Nikolai Posted August 27, 2012 Share Posted August 27, 2012 I figure this should be split off from the other banter thread as it's a topic so many here are familiar with and eager to discuss: a hurricane striking New Orleans. Models are currently scattered along the Gulf Coast from Shreveport through to Mobile, but this thread is specific to New Orleans and the impact that Isaac is likely to have on the city. What kind of changes have been made to the city's levee system since Katrina? I know the Army Corps of Engineers is building an enormous new system, but completion wasn't scheduled until later on in 2012--and who knows if they would have pushed it back even further. Is the new levee system adequate or even ready for a potential Category 2+ Isaac's impacts on New Orleans? Also important is Isaac's approach. Unlike Katrina, which was moving due North by the time New Orleans felt the impact, Isaac will be moving WNW if it does indeed hit New Orleans. What are the different implications from a storm that arrives from the Southeast and potentially lingers over the city for 24 hours? Discuss! Link to comment Share on other sites More sharing options...
Indystorm Posted August 27, 2012 Share Posted August 27, 2012 Hurricane Gustav made landfall as a category 2 hurricane and NOLA survived, albeit with the largest mass evacuation in the state's history of nearly 2 million people, 200,000 of whom were from NOLA. Link to comment Share on other sites More sharing options...
Witness Protection Program Posted August 27, 2012 Share Posted August 27, 2012 Models are currently scattered along the Gulf Coast from Shreveport through to Mobile, but this thread is specific to New Orleans and the impact that Isaac is likely to have on the city. If Isaac comes ashore at Shreveport, NOLA will have become Atlantis. Link to comment Share on other sites More sharing options...
Nikolai Posted August 27, 2012 Author Share Posted August 27, 2012 Doomsday track for NOLA on NHC's 11PM forecast. + Link to comment Share on other sites More sharing options...
Nikolai Posted August 27, 2012 Author Share Posted August 27, 2012 The entire southern portion of Louisiana is literally at or a few feet above sea level. Does anyone have data on how much land was lost to Katrina? If Isaac does make landfall near NOLA and also stalls as models indicate, I would imagine the potential for enormous land-loss and coastal erosion would be quite high. The region is already extremely vulnerable and such a long-lasting and powerful event could do a major number on swamps that are already being swallowed by the ocean every day. Something else to keep in mind is that New Orleans continues to sink each year. Here's a study from 2005 with data showing parts of the city sinking over an inch every year. That's not a huge difference from 2005, but it should be kept in mind that New Orleans is actually lower in elevation now than it was then, however minimal the difference may be (6-12 inches in most of the city). http://earthobservatory.nasa.gov/IOTD/view.php?id=6623 Link to comment Share on other sites More sharing options...
real Posted August 27, 2012 Share Posted August 27, 2012 Looking at that map, is it really realistic to think the hurricane would just be off shore the mouth of the Mississippi at 8 p.m. Tuesday but then, still a hurricane, just north of Lake Pontchartrain at 8 pm. Wednesday, 24 hours later. I know models show system slowing upon landfall, but that seems hard to believe. If even it did slow that much, could it really stay a cane on that entire 24-hour slog? Link to comment Share on other sites More sharing options...
Indystorm Posted August 27, 2012 Share Posted August 27, 2012 Mandatory evacuation for St. Charles Parish in LA....over 50,000 people. Link to comment Share on other sites More sharing options...
Indystorm Posted August 27, 2012 Share Posted August 27, 2012 Lessons from Katrina.... Mayor Landrieu: Our position is that we are not going to have shelters of last resort. People cannot rely on the city sheltering people in the event of a major storm. And we will take whatever precautions we need to protect people but unfortunately people hear that the wrong way and they don’t make provisions for their families and for themselves and we get into the situation that we had during Katrina and Rita and we do not want to do that again. Link to comment Share on other sites More sharing options...
EastCoastLow Posted August 27, 2012 Share Posted August 27, 2012 My understanding is also that the pump system didn't cope with Katrina, water levels in the city were rising well before levee breach. Maybe another major storm (if Isaac does become decent) will finally make people realise what a folly New Orleans is from a geographical point of view. Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 543 AM CDT WED AUG 22 2012 .SHORT TERM... UPPER LEVEL TROUGH WILL REMAIN OVER THE LOWER MISSISSIPPI VALLEY AND NORTHERN GULF OF MEXICO AREA TODAY WITH VORTICITY MAXIMA MOVING THROUGH. STALLED FRONTAL BOUNDARY IS EXPECTED TO REMAIN OFFSHORE...HOWEVER...ISENTROPIC LIFT WILL PRODUCE ABUNDANT CLOUD COVER AT LEAST EARLY THIS MORNING WITH BREAKS EXPECTED BY LATE MORNING AND AFTERNOON. THERE MAY BE SOME PATCHES OF LIGHT RAIN MIXED WITH SOME ISOLATED SHOWERS AND THUNDERSTORMS TODAY...MAINLY ALONG AND SOUTH OF THE I-12/10 CORRIDOR. ANY RAINFALL TODAY SHOULD REMAIN GENERALLY LIGHT...BUT POSSIBLY A BIT MORE PERSISTENT IN SOME SOUTHEAST LOUISIANA COASTAL AREAS. THERE HAS BEEN A BETTER SURGE OF LOWER DEWPOINTS OVERNIGHT...AND THIS SHOULD LEAD TO A MORE NOTICEABLE DROP IN HUMIDITY TODAY. AM FORECASTING HIGHS NEAR 90 IN MOST AREAS...HOWEVER...IF CLOUDS STAY THICK THEN THE HIGHS MAY HOLD IN THE MID 80S. REGARDLESS...IT SHOULD BE UNSEASONABLY PLEASANT FOR AUGUST WITH THE LOWER HUMIDITY IF YOU STAY OUT OF THE MIDDAY SUN. TONIGHT THROUGH FRIDAY...THE MAIN UPPER TROUGH WILL WEAKEN OVER THE EASTERN U.S. WITH THE TRAILING SHEAR AXIS SETTLING SOUTHEAST OVER THE NORTHERN GULF OF MEXICO. WINDS IN THE LOWER TO MID LEVELS WILL BECOME RATHER LIGHT...SO THERE WILL BE LITTLE CHANGE IN AIRMASS. THIS MEANS THE EFFECTS OF THE DRIER CONTINENTAL AIRMASS WILL BE SLOW TO TRANSITION BACK TO OUR NORMAL HUMID TROPICAL. HAVE SOME LOW END POPS...GENERALLY 20 TO 30 PERCENT...MAINLY IN SOUTHERN PORTIONS OF THE FORECAST AREA...BUT ANY RAIN SHOULD BE RATHER HIT OR MISS...AND BRIEF. LESS CLOUD COVER TONIGHT WILL ALLOW THE TEMPERATURES TO FINALLY DIP WELL INTO THE 60S OVER AREAS AWAY FROM THE WARMING EFFECTS OF THE TIDAL LAKES AND SOUTHEAST LOUISIANA COASTAL BAYS AND SOUNDS. THE DRIER AIR AND PARTLY TO MOSTLY SUNNY SKIES WILL STILL HEAT UP EFFICIENTLY WITH NEAR 90 DEGREE HIGHS EXPECTED THURSDAY AND FRIDAY. .LONG TERM... THE MAIN CONCERN OBVIOUSLY WILL BE THE TRACK AND STRENGTH OF TROPICAL STORM ISAAC. THE OFFICIAL FORECAST FOLLOWS A WEST TO WEST NORTHWEST TRACK AROUND THE PERIPHERY OF THE MID LEVEL ATLANTIC RIDGE...REACHING SOUTH OF PUERTO RICO AS A HURRICANE THURSDAY AFTERNOON...NEAR HISPANOLIA FRIDAY...EASTERN CUBA SATURDAY...AND BACK OVER THE ATLANTIC BETWEEN NORTH CENTRAL CUBA AND SOUTHEAST FLORIDA ON SUNDAY. THE CONE OF UNCERTAINTY AT 2 AM MONDAY EXTENDS FROM THE FAR EASTERN GULF OF MEXICO ACROSS THE SOUTHERN HALF OF THE FLORIDA PENINSULA TO THE BAHAMAS. BEYOND THAT TIME...THE GFS AND ECMWF SHOW A STRONG AND PROGRESSIVE SHORTWAVE TROUGH MOVING SOUTHEAST THROUGH THE GREAT LAKES AND OHIO VALLEY MONDAY INTO TUESDAY. BOTH MODELS SHOWS A FAIRLY STRONG 500 MB HIGH CENTERED OVER THE SOUTHERN ROCKIES AND OKLAHOMA/TEXAS PANHANDLE REGION. THE SHORTWAVE TROUGH MAY BE TOO FAR NORTH TO RE-CURVE ISAAC...SO A TRACK INTO THE EASTERN GULF OF MEXICO IS STILL A GOOD POSSIBILITY. BEYOND THAT TIME...THERE IS TOO MUCH UNCERTAINTY TO SPECULATE ON WHETHER THE DEEP LAYER STEERING CURRENTS WOULD DRAW ISAAC NORTH OR NORTHWEST. THE LOCAL WEATHER IS LIKELY TO REMAIN DRIER WITH RAIN CHANCES GENERALLY BELOW NORMAL WITH MAINLY ISOLATED DIURNAL SHOWERS AND THUNDERSTORMS. TEMPERATURES SHOULD TREND NEAR TO SLIGHTLY ABOVE SEASONAL AVERAGES FOR HIGHS AND NEAR AVERAGE FOR LOWS. && .AVIATION... VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE PERIOD WITH EAST TO SOUTHEAST WINDS LESS THAN 10 KNOTS. SOME PATCHY LIGHT FOG MAY RESULT IN MVFR CONDITIONS TOWARD DAYBREAK. $$ .MARINE... THE STALLED FRONTAL BOUNDARY WILL SERVE AS A FOCUS FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY OVER THE OUTER GULF WATERS TODAY. WITH A LAX GRADIENT IN PLACE...EXPECT WINDS TO REMAIN 10 KNOTS OR LESS FOR THE NEXT FEW DAYS. RETURN TO LIGHT ONSHORE FLOW EXPECTED WEDNESDAY AS THE FRONT BECOMES DIFFUSE. LATE IN THE PERIOD WINDS GAIN A NORTHERLY COMPONENT ATTRIBUTED TO THE FRINGES OF THE CIRCULATION AROUND ISAAC. Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 419 PM CDT WED AUG 22 2012 .SYNOPSIS... LATEST SURFACE ANALYSIS SHOWED A 1019MB HIGH OVER THE NORTH CENTRAL GULF AND A DISSOLVING NEARLY STATIONARY BOUNDARY FROM SOUTH GEORGIA TO NORTH CENTRAL GULF. SURFACE DEWPOINT READINGS WERE FROM LOWER 70S ALONG THE SOUTHEAST LOUISIANA COAST TO UPPER 50S ACROSS SOUTHWEST MISSISSIPPI. PRECIPITABLE WATER VALUE PLOTS FROM THIS MORNING REGIONAL SOUNDINGS SHOWED VALUES BELOW 1 INCH NEAR OR NORTH OF 1-20...1.44 INCHES AT LIX...AND INITIALIZED DATA VALUE OF 1.8 INCHES ALONG SOUTH OF TIDAL LAKES. UPPER AIR ANALYSIS SHOWED THE RIDGE OVER WEST TEXAS...NEW MEXICO...BERMUDA RIDGE ACROSS WEST ATLANTIC TO BAHAMAS AND WEAK TROUGH AXIS ACROSS THE LOWER MISSISSIPPI VALLEY. IN ADDITION...TROPICAL STORM ISAAC NEAR THE LEEWARD ISLANDS. && .DISCUSSION... THE MAIN TROUGH WILL SLIGHTLY DEEPEN ALONG THE EASTERN SEABOARD THROUGH THURSDAY. THIS WILL DRIVE DRY AIR SOUTHEAST EAST OF MISSISSIPPI RIVER TO FLORIDA. WITH LESS OF A PUSH TO THE WEST...DEEP MOISTURE WILL MIGRATE NORTH AND MAINTAIN RAIN CHANCE WEST OF LAKE PONTCHARTRAIN FOR THURSDAY. THIS PIVOT POINT AND REMNANTS OF DRY AIR WILL SLOWLY DRIFT EAST LATE THURSDAY THROUGH FRIDAY. THUS RAIN CHANCES WILL RETURN ACROSS THE FORECAST AREA THURSDAY NIGHT WITH THE BEST CHANCES TO THE WEST. PRECIPITABLE WATER VALUES WILL RETURN TO NEAR 1.8 TO 1.9 INCHES WITH A SLIVER OF 1.5 INCHES ACROSS THE EXTREME PARTS OF MISSISSIPPI COAST. ERGO...WILL UP AREA TO CHANCE OF RAIN BY SATURDAY WITH JUST A SLIGHT CHANCE NEAR PQL OVER THE WEEKEND. A STRONG SHORT WAVE IS EXPECTED TO TRACK ACROSS THE PLAINS RIDGE SATURDAY TO THE GREAT LAKES REGION MONDAY. WITH APPROACHING ISAAC...SUBSIDENCE TO THE NORTHWEST OF THE SYSTEM WILL DIMINISH RAIN CHANCES ACROSS THE AREA NEXT WEEK. TROPICAL STORM ISAAC IS EXPECTED TRACK NORTHWEST INTO THE FAR EASTERN GULF BY MONDAY AND POSSIBLY NEAR 30N AND 83W BY WEDNESDAY ACCORDING HPC. WILL MAINTAIN A SOMEWHAT DRY FORECAST FOR NEXT WEEK BASED ON THIS TRACK. && .AVIATION... VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE PERIOD WITH EAST TO SOUTHEAST WINDS LESS THAN 10 KNOTS. WINDS WILL BECOME NEARLY CALM BY 03Z THURSDAY. SOME PATCHY LIGHT FOG MAY RESULT IN MVFR CONDITIONS THURSDAY MORNING. && .MARINE... THE STALLED FRONTAL BOUNDARY WILL SERVE AS A FOCUS FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY OVER THE OUTER GULF WATERS THROUGH TONIGHT. THE PRESSURE GRADIENT REMAINS VERY WEAK AND WINDS WILL REMAIN 10 KNOTS OR LESS FOR THE NEXT FEW DAYS. BY WEDNESDAY...WINDS MAY INCREASE WITH A NORTHERLY COMPONENT ATTRIBUTED TO THE FRINGES OF THE CIRCULATION AROUND ISAAC. Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 546 AM CDT THU AUG 23 2012 .SHORT TERM... GENERALLY QUIET WEATHER PATTERN WILL PREVAIL LOCALLY...HOWEVER RAIN CHANCES WILL GO UP A BIT FRIDAY INTO SATURDAY AS THE STALLED FRONTAL BOUNDARY NEAR THE SOUTH LOUISIANA COAST SLOWLY MOVES BACK NORTH AND BECOMES DIFFUSE. THE BETTER CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE NEAR THE FRONTAL BOUNDARY TODAY...AND OVER SOUTH LOUISIANA AND SOUTHWEST MISSISSIPPI FRIDAY AND SATURDAY. TEMPERATURES SHOULD REMAIN SLIGHTLY BELOW CLIMO AVERAGES. LATEST VORTEX MESSAGE FROM RECON ON ISAAC AND EASTERN CARIBBEAN SEA BUOY DATA STILL SHOWS A DISORGANIZED SYSTEM AT THE SURFACE WITH PRESSURES NOT FALLING AND WINDS BELOW 35 KNOTS...HOWEVER THE SATELLITE PRESENTATION IS VERY IMPRESSIVE...SO EVENTUAL STEADY INTENSIFICATION IS IMMINENT WHILE THE STORM REMAINS OVER WATER. ISAAC IS FORECAST TO TRACK WEST TO WEST NORTHWEST TOWARDS THE SOUTH AND WEST COAST OF HISPANIOLA ON FRIDAY/FRIDAY NIGHT AND EASTERN CUBA ON SATURDAY. REFER TO THE LATEST ADVISORIES FROM THE NATIONAL HURRICANE CENTER. .LONG TERM... A MOSTLY DRY PATTERN IS EXPECTED AS DEEP LAYER WINDS START TO FAVOR NORTHEAST TO NORTH AROUND THE CIRCULATION OF ISAAC BY LATE SUNDAY THROUGH WEDNESDAY. THE OFFICIAL FORECAST TRACK BRINGS ISAAC INTO THE SOUTHEAST GULF OF MEXICO LATE SUNDAY NIGHT AS A CATEGORY ONE HURRICANE LATE SUNDAY NIGHT. THE MODELS HAVE LESS SPREAD TODAY WITH THE 00Z ECMWF HAVING SHIFTED EAST TOWARDS MOB/PNS...AND THE 00Z GFS SLIGHTLY WEST TOWARDS AQQ/TLH. AT THIS TIME...THE MAIN IMPACT FROM ISAAC IS EXPECTED TO BE HAZARDOUS BOATING CONDITIONS OFFSHORE AS WINDS AND SWELLS INCREASE...ESPECIALLY EAST OF SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM MONDAY NIGHT THROUGH WEDNESDAY MORNING. && .AVIATION... SPOTTY LOCATIONS ACROSS THE AREA HAVE REPORTED LIGHT FOG THIS MORNING. THIS WILL CONTINUE UNTIL SUNRISE WITH VIS DROPPING INTO MVFR RANGE. OTHERWISE...VFR WILL PREVAIL THROUGH THE NEXT 24 HRS AT TERMINALS. WINDS TO BE QUITE LIGHT AT 5 TO 10 KNOTS WITH DIRECTION RANGING FROM EAST IN THE NORTH TO SOUTHEAST OVERNIGHT. TO THE NORTH THERE WILL BE LITTLE IN THE WAY OF EVEN CLOUDS WITH SUCH DRY AIR. SHOWERS AND STORMS ARE POSSIBLE TODAY BUT MAINLY ALONG AND SOUTH OF A HUM TO MSY LINE. MEFFER $$ .MARINE... STALLED FRONTAL BOUNDARY OVER THE COASTAL WATERS WILL CONTINUE TO BE A FOCUS FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TODAY. WEAK SURFACE PATTER IN PLACE WILL KEEP WINDS ON THE WEAKER SIDE BUT B/C IT IS HIGH PRESSURE TO THE EAST DOING THE INFLUENCING... DIRECTION TO BE MOSTLY EAST TO SOUTHEAST. THIS PATTERN WILL CONTINUE WELL INTO THE WEEKEND. MOVING INTO NEXT WEEK THE TRACK OF TROPICAL STORM ISAAC WILL HAVE LARGE AFFECTS ON WINDS AND SEAS THROUGH THE COASTAL WATERS EVEN IF THE STORM TRACKS IN THE FAR EASTERN GULF OF MEXICO. CURRENT FORECAST IS A BLEND OF ECMWF AND GFS WINDS. THE OUTER WATERS WILL BE IMPACTED WITH THE STRONGEST WINDS OF SMALL CRAFT TO POSSIBLY GALE TUES THROUGH WED. RESULTING SEAS ARE IN THE 8 TO 10 FOOT RANGE WITH THAT FETCH AND WIND SPEEDS. FCST CHANGE FROM NOW TO EVENT HIGHLY DEPENDENT ON TRACK OF THE STORM. MEFFER $$ .DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SUPPORTING SLURRY EVACUATIONS IN ASSUMPTION PARISH. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 358 PM CDT THU AUG 23 2012 .SYNOPSIS... UPPER AIR ANALYSIS CONTINUE TO SHOW A TROUGH AXIS FROM NORTHEAST CONUS TO NORTHEAST GULF...A SHORT WAVE NEAR THE FOUR CORNERS REGION AND RIDGES OVER BAJA CALIFORNIA TO MID MISSISSIPPI VALLEY AND WEST ATLANTIC TO BAHAMAS. DIVERGENCE AT THE BASE OF TROUGH AND THE FRONT SIDE OF THE RIDGE HAS ALLOWED ASCENT AND CONVECTION OVER NORTHWEST GULF. PRECIPITABLE WATER PLOTS SHOWED THE DRY AIR BEHIND THE TROUGH WITH SUB 1 INCH VALUES NORTH OF I-20 BUT 1.4 INCHES AT LIX AND 1.68 INCHES AT LCH. SURFACE ANALYSIS CONTINUE TO SHOW A VERY WEAK PRESSURE GRADIENT ACROSS THE SOUTHEAST...MAINLY A BROAD 1018MB HIGH FROM NORTHEAST GULF TO NORTHEAST CONUS. && .DISCUSSION... DISTURBANCE AT THE BASE OF THE UPPER LEVEL TROUGH WILL LIFT NORTHEAST THROUGH FRIDAY TO THE MID ATLANTIC STATES. THIS WILL ALLOW THE NORTHWEST FLOW BEHIND TROUGH TO SHIFT EAST AND WEAKEN OVER THE LOWER MISSISSIPPI VALLEY THROUGH. AS A RESULT...DEEPER MOISTURE WILL ADVECT IN FROM SOUTHWEST. PRECIPITABLE WATER VALUES MAY RANGE FROM 2 INCHES OVER BATON ROUGE AREA TO 1.2 INCHES OVER PQL...ERGO BETTER CHANCES OF RAIN FOR WEST ZONES FRIDAY. DEEPER MOISTURE WILL INCH FARTHER EAST THROUGH SATURDAY INTO SUNDAY WITH BETTER CHANCES OF RAIN INCH FARTHER EAST TO THE PEARL RIVER AND PORTION OF THE MISSISSIPPI COAST BY SUNDAY. USING THE OFFICIAL FORECAST FROM NHC TRACK FORECAST FOR ISAAC...ISAAC IS EXPECTED TO REACH 80W BY SUNDAY. BROAD CIRCULATION AROUND ISAAC WILL HALT DRY EASTWARD PROGRESSION LATE SUNDAY AND THIS DRY AIR WILL BEGIN TO DRIFT WEST. ADDED WITH DESCENT OF AIR TO THE NORTHWEST OF ISAAC...RAIN CHANCES ARE EXPECTED TO DECREASE MONDAY AND TUESDAY. WESTERN FRINGES OF ISAAC WILL LIKELY INCREASE RAIN CHANCES OVER COASTAL WATERS TUESDAY INTO WEDNESDAY. IN ADDITION...WARM AND DRY AIR WILL RESULT INTO HIGH TEMPERATURES WELL INTO THE 90S FOR MID NEXT WEEK. && .AVIATION... VFR WILL BE THE PREVAILING WEATHER AT ALL 8 TERMINALS THROUGH THE NEXT 24. WINDS TO BE QUITE LIGHT AT 5 TO 10 KNOTS WITH DIRECTION RANGING FROM EAST IN THE NORTH TO SOUTHEAST OVERNIGHT. SPOTTY LOCATIONS ACROSS THE AREA HAVE REPORTED LIGHT FOG AGAIN FRIDAY MORNING. CONVECTION MAY AFFECT MORE SITES FRIDAY AFTERNOON...EXCLUDING GPT. && .MARINE... WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE THROUGH THE WEEKEND WITH AN EASTERLY FLOW IN PLACE. FAST FORWARD TO NEXT WEEK... THE TRACK OF TROPICAL STORM ISAAC WILL HAVE LARGE AFFECTS ON WINDS AND SEAS THROUGH THE COASTAL WATERS EVEN IF THE STORM TRACKS IN THE EASTERN GULF OF MEXICO. CURRENT FORECAST IS A BLEND OF ECMWF AND GFS WINDS. THE OUTER WATERS WILL BE IMPACTED WITH THE STRONGEST WINDS OF SMALL CRAFT TO POSSIBLY GALE TUES THROUGH WED. RESULTING SEAS ARE IN THE 8 TO 10 FOOT RANGE WITH THAT FETCH AND WIND SPEEDS. FCST CHANGE FROM NOW TO EVENT HIGHLY DEPENDENT ON TRACK OF THE STORM. Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 447 AM CDT FRI AUG 24 2012 .DISCUSSION... DEEPER MOISTURE WILL BEGIN TO ADVECT INTO THE REGION TODAY AS AN AREA OF DISTURBED WEATHER IS JUST OFF TO THE WEST THE FORECAST AREA. EXPECT HIGHER RAIN CHANCES AND BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS TODAY ESPECIALLY FOR AREAS ALONG AND WEST OF INTERSTATE 55. WILL CARRY LIKELY POPS TODAY FOR WESTERN AREAS AND CHANCE POPS FOR EASTERN AREAS. EXPECT MOISTURE TO CONTINUE TO INCREASE THROUGH THE WEEKEND AND AFTERNOON RAIN CHANCES TO PERSIST THROUGH THE WEEKEND. ONLY EXPECTING A 20 TO 30 PERCENT CHANCE OF AFTERNOON SHOWERS THROUGH THE WEEKEND.THE LONGER RANGE FORECAST DEPENDS SOLELY ON THE PATH THAT TROPICAL STORM ISAAC TAKES. THE CURRENT FORECAST ACCOUNTS FOR A FURTHER EAST TRACK. RIGHT NOW HAVE ONLY CHANCE POPS FOR THE MISSISSIPPI COAST WEDNESDAY MORNING AND SLIGHT CHANCE FOR THE REST OF THE FORECAST AREAS. EXPECT RAIN CHANCES TO LINGER THROUGH EARLY THURSDAY MORNING AS ISAAC LIFTS OUT OF THE AREA. EXPECT TEMPERATURES TO REACH IN THE LOW 90S EARLY NEXT WEEK. TROPICAL STORM ISAAC IS STILL STRUGGLING TO COMPLETELY ORGANIZE THIS MORNING. RECON FLIGHTS HAVE BEEN OUT OVER ISAAC ALL MORNING AND HAVE FOUND A FEW VORT MAXES AND SOME STRONGER SURFACE WINDS EMBEDDED IN THE DEEPEST CONVECTION. THE LATEST OFFICIAL FORECAST HAS ADJUSTED THE INITIAL FORECAST POINT A LITTLE BIT FURTHER SOUTH THIS MORNING. THE FORECAST STILL HAS ISAAC MAKING LANDFALL BETWEEN MOBILE AND PENSACOLA EARLY WEDNESDAY MORNING AS A CATEGORY ONE HURRICANE. LAST NIGHTS MODEL RUNS SUPPORT THIS AS THE ECMWF THE WESTERN MOST MODEL SHIFTED BACK EASTWARD SUPPORTING A LANDFALL AROUND MOBILE BAY AND THE GFS RUN CAME IN WITH A LANDFALL AT PENSACOLA. THE GFS IS A LITTLE BIT MORE PROGRESSIVE WITH THE MOVEMENT OF ISSAC BUT BOTH MODELS ARE PRETTY CLOSE WITH THE INTENSITY. IF THE CURRENT TRACK HOLDS UP THE IMPACT FROM ISAAC WILL NOT BE SIGNIFICANT. HOWEVER...IF ISAAC CONTINUES TO STRUGGLE TO ORGANIZE AND THE CENTER OF CIRCULATION CONTINUES TO JOG MORE SOUTH AND WEST THE TRACK COULD CHANGE SHIFT MORE WEST WITH A GREATER IMPACT TO THE AREA. WE WILL DEFINITELY HAVE TO WATCH THE EVOLUTION AND PROGRESSION OF ISAAC AS THE DAY GOES ON. 13/MH && .AVIATION... CURRENTLY VFR CONDITIONS ACROSS THE AREA BUT CLOUD COVER HAS BEEN INCREASING. CANNOT RULE OUT A FEW MVFR VISIBILITIES AS WE APPROACH SUNRISE...ESPECIALLY AT KHUM AND KASD. AS MOISTURE RETURNS TO WESTERN PORTIONS OF THE CWA TODAY...PRECIPITATION CHANCES WILL INCREASE IN THOSE AREAS. WILL USE TEMPO GROUPS AT KHUM AND KBTR DURING THE AFTERNOON HOURS...WITH PROB30 GROUPS AT KMSY...KNEW...KHDC AND KMOB DUE TO STEEPER GRADIENT OF RAIN CHANCES FROM WEST TO EAST. WILL KEEP KASD AND KGPT DRY. CONVECTION WILL DISSIPATE AGAIN BY 01Z. MEFFER && .MARINE... CONDITIONS WILL BE QUITE ACTIVE IN TERMS OF CONVECTION IN COASTAL WATERS WEST OF THE MISSISSIPPI RIVER IN RESPONSE TO AN INVERTED TROUGH TO THE WEST. RAIN CHANCES DECREASE THROUGH THE WEEKEND. WEAK SURFACE PATTER IN PLACE WILL KEEP WINDS ON THE WEAKER SIDE TODAY AT 5 TO 10 KNOTS. THIS PATTERN WILL NOT CHANGE ALL THAT MUCH THIS WEEKEND BUT COULD SEE A MORE CONSISTENT 10 KNOTS TO SLIGHTLY ABOVE THAT OFFSHORE WITH SEAS BUILDING A LITTLE AS WELL. MOVING INTO NEXT WEEK THE TRACK OF TROPICAL STORM ISAAC WILL HAVE LARGE AFFECTS ON WINDS AND SEAS THROUGH THE COASTAL WATERS EVEN IF THE STORM TRACKS IN THE FAR EASTERN GULF OF MEXICO. CURRENT FORECAST IS A BLEND OF ECMWF AND GFS WINDS. THE OUTER WATERS WILL BE IMPACTED WITH THE STRONGEST WINDS OF SMALL CRAFT TO POSSIBLY GALE...IF NOT HIGHER... TUES THROUGH WED. RESULTING SEAS ARE IN THE 8 TO 12 FOOT RANGE WITH THAT FETCH AND WIND SPEEDS. FCST CHANGE FROM NOW TO EVENT HIGHLY DEPENDENT ON TRACK OF THE STORM. MEFFER .DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SUPPORTING SLURRY EVACUATIONS IN ASSUMPTION PARISH. MONITORING TROPICAL STORM ISAAC. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 413 PM CDT FRI AUG 24 2012 .SYNOPSIS... UPPER AIR ANALYSIS SHOWS TWO SYSTEMS...ONE TO THE NORTHWEST AND THE OTHER SOUTHEAST OF THE FORECAST AREA...THAT MAY POSSIBLY MEET OR INTERACT JUST EAST OF THE AREA. A VIGOROUS UPPER LEVEL CYCLONIC CIRCULATION OVER THE FOUR CORNERS REGION AND TROPICAL STORM ISAAC SOUTH OF HAITI. AT THE SURFACE...RIDGE OF HIGH PRESSURE WAS LOCATED OVER NORTHEAST CONUS TO NORTHEAST GULF. PRECIPITABLE WATER PLOTS SHOWED VALUES NEAR 2 INCHES NEAR SLIDELL AND DEEPER MOISTURE WEST. IN ADDITION...SEVERAL DISTURBANCES WERE OVER SOUTHEAST TEXAS AND NORTHWEST GULF TRIGGERING CONVECTION. && .DISCUSSION... SURFACE RIDGE WILL REMAIN IN PLACE WITH THE AXIS FROM MID ATLANTIC STATES TO SOUTHEAST TEXAS. AS A RESULT...SURFACE AND LOW LEVEL FLOW WILL REMAIN EASTERLY THROUGH THE WEEKEND. THE APPROACH OF THE SHORT WAVE OVER THE FOUR CORNERS REGION WILL PULL THE DEEP MOISTURE POOL OVER LOUISIANA MOISTURE NORTH. DISTURBANCES WILL MOVE SOUTH OVER NORTHWEST GULF SATURDAY AND COVERAGE OF CONVECTION WILL SCATTERED OVER WEST ZONES SATURDAY AND SUNDAY. TOWARD THE END OF THE WEEKEND...THE CIRCULATION AROUND APPROACHING ISAAC WILL PULL SOME DRY AIR BACK WEST OF THE FORECAST AREA FROM EAST TO WEST STARTING LATE SUNDAY THROUGH EARLY TUESDAY. WITH THE CURRENT OFFICIAL NHC TRACK...INCREASED RAIN CHANCES TO LIKELY TUESDAY AND TUESDAY NIGHT OVER THE COASTAL WATERS EAST OF THE MISSISSIPPI RIVER. BOTH NHC AND HPC ARE FORECAST THIS TROPICAL SYSTEM TO THE TRACK NORTH TUESDAY INTO WEDNESDAY NORTH OF 30N. VIGOROUS WAVE OVER FOUR CORNER REGION WILL TRACK TO THE GREAT LAKES REGION BY MONDAY WITH TRAIL AXIS TO NORTH LOUISIANA. THIS AXIS IS EXPECTED TO PICK UP ISAAC AND LIFT THE TROPICAL SYSTEM NORTH LATE TUESDAY THROUGH WEDNESDAY. NORTH WINDS TO THE WEST OF THE TROPICAL SYSTEM WILL DRIVE SOUTH OVER THE AREA THURSDAY AND FRIDAY...THUS DECREASING RAIN CHANCES FOR THIS TIME PERIOD. && .MARINE... WEAK PRESSURE GRADIENT AND RIDGE FROM MID ATLANTIC TO SOUTHEAST WILL MAINTAIN AN EAST TO NORTHEAST FLOW OVER THE COASTAL WATERS THROUGH THE WEEKEND. THIS FLOW MAY SLOWLY INCREASE AS ISAAC ENTERS THE SOUTHEAST GULF EARLY MONDAY WITH NORTHEAST WINDS INCREASING UP TO 20 KNOTS BY MONDAY MORNING. WITH THE OFFICIAL TRACK OF ISAAC...WINDS AND WAVES ARE EXPECTED TO INCREASE MONDAY THROUGH TUESDAY. THE OUTER WATERS WILL BE IMPACTED WITH THE STRONGEST WINDS OF SMALL CRAFT TO POSSIBLY GALE...IF NOT HIGHER... TUES THROUGH WED. RESULTING SEAS ARE IN THE 12 TO 17 FEET RANGE WITH THAT FETCH AND WIND SPEEDS. FCST CHANGE FROM NOW TO EVENT HIGHLY DEPENDENT ON TRACK OF THE STORM. && .AVIATION... SCATTERED CONVECTION WILL CONTINUE TO IMPACT AREA TERMINALS THROUGH THE EVENING HOURS. HAVE KEPT IN VCTS WORDING DUE TO THE COVERAGE...AND HAVE ALSO KEPT A TEMPO GROUP IN FOR THE TERMINALS UNTIL 22Z. THE STRONGEST STORMS COULD PRODUCE BRIEF PERIODS OF IFR RESTRICTIONS AND STRONG WIND GUSTS OVER 25 KNOTS. THE CONVECTIVE THREAT WILL DIMINISH BY 02Z...WITH VFR CONDITIONS BEING THE RULE OVERNIGHT. HOWEVER...A WEAK INVERSION MAY ALLOW FOR SOME LIGHT FOG FORMATION AT KMCB AROUND 10-12Z IN THE MORNING. EXPECT ANOTHER ROUND OF CONVECTION TO DEVELOP AFTER 15Z TOMORROW...AS A TROUGH LINGERS OVER THE GULF SOUTH. HAVE PUT IN VCSH AFTER 15Z TO REFLECT THE CONTINUED HIGH RISK OF CONVECTION. 32 $$ .DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...MONITORING TROPICAL STORM ISAAC. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 351 AM CDT SAT AUG 25 2012 .SHORT TERM... A MID LEVEL SHORT WAVE TROUGH LIFTING OUT OF THE CENTRAL AND SOUTHERN PLAINS AND ACROSS THE MID AND LOWER MISSISSIPPI VALLEY TODAY WILL AID IN THE DEVELOPMENT OF SCATTERED CONVECTION AS IT ACTS UPON A STILL RELATIVELY MOIST AND UNSTABLE ATMOSPHERE. THE BEST CHANCES FOR CONVECTION WILL BE ACROSS THE NORTHWESTERN SECTIONS WHERE THE BEST LIFT WILL BE LIFT WILL BE LOCATED. THE SHOWER AND THUNDERSTORM ACTIVITY WILL WANE AFTER SUNSET. 11 .LONG TERM... TROPICAL STORM ISAAC IS FORECAST TO TRACK OUT OF THE NORTHERN CARIBBEAN AND INTENSIFY INTO A HURRICANE AS IT MOVES ACROSS THE FLORIDA STRAITS AND INTO THE EASTERN GULF MEXICO OVER THE NEXT FEW DAYS AS IT MOVES INTO A WEAKNESS IN THE UPPER RIDGE AS AN UPPER TROUGH DIGS ACROSS THE EASTERN U.S. ALTHOUGH THERE IS STILL SOME DIVERGENCE WITH THE MODEL SOLUTIONS AS ISAAC MOVES ACROSS THE EASTERN GULF...OVERALL THE MODEL CONSENSUS BRINGS ISAAC INTO THE PANHANDLE OF FLORIDA LATE TUESDAY OR TUESDAY NIGHT. THE ECMWF SOLUTION HAS SHIFTED NOTICEABLY TO THE EAST AND IS CLOSE TO THE GFS THROUGH LANDFALL. AFTER LANDFALL HOWEVER...THE ECMWF SOLUTION HAS ISAAC BEING LEFT BEHIND BY THE UPPER TROUGH RESULTING IN IT LINGERING OVER THE GULF COAST REGION WHILE THE GFS CONTINUES TO MOVE IT NORTHWARD. AT THIS TIME...A SLOW NORTHWARD PROGRESSION OF THE SYSTEM IS EXPECTED. ON THIS TRACK THE VAST MAJORITY OF THE RAINFALL WILL STAY EAST OF THE FORECAST AREA. AS ISAAC MOVES INTO THE EASTERN GULF...DRIER AIR WILL BE DRAWN INTO THE REGION. THIS ALONG WITH SUBSIDENCE WILL RESULT IN LOW RAIN CHANCES SUNDAY AND MONDAY ALONG WITH SOMEWHAT HIGHER DAYTIME TEMPERATURES. RAIN CHANCES WILL INCREASE ACROSS PRIMARILY THE EASTERN SECTIONS OF THE FORECAST AREA TUESDAY AS ISAAC MOVES TOWARD THE NORTHEAST GULF. THE HIGHER RAIN CHANCES WILL CONTINUE WEDNESDAY ACROSS EASTERN AREAS OF THE FORECAST AREA AS ISAAC MOVES INLAND. DRIER AIR WILL FILTER INTO THE AREA AGAIN IN THE WAKE OF ISAAC FOR THE END OF THE WEEK. 11 && .AVIATION... SATELLITE SHOWS WIDESPREAD COVERAGE OF CLOUD COVER ACROSS THE AREA BUT THE DECK IS WELL ABOVE 10K FEET SO GENERALLY VFR CONDITIONS HAVE BEEN OBSERVED. A FEW SPOTS OF LIGHT FOG STILL POSSIBLE BEFORE SUNRISE. MOISTURE PATTERN ON SATURDAY FAIRLY SIMILAR TO FRIDAY...WITH MOST PRECIPITATION CONCENTRATED ALONG AND WEST OF INTERSTATE 55. WILL CARRY TEMPO TSRA GROUPS WITH MVFR CONDITIONS FOR THE AFTERNOON FOR KHUM...KBTR...KHDC AND KMCB. PRECIPITATION WILL DIE OUT SHORTLY AFTER SUNSET. MEFFER && .MARINE... EASTERLY FLOW WILL BE ON THE INCREASE TODAY IN RESPONSE TO PRESSURE GRADIENT ALREADY BEGINNING TO TIGHTEN BETWEEN SURFACE RIDGE TO THE NORTHEAST AND TROPICAL STORM ISAAC TRACKING NORTHWEST TOWARDS THE GULF. SEAS WILL SLOWLY BEGIN RESPONDING AS WELL. EXPECT WIND DIRECTION TO GRADUALLY VEER TOWARDS THE NORTHEAST SUNDAY AND MONDAY. MORE SUBSTANTIAL WIND SPEEDS LIKELY TO BE OBSERVED IN OUTER WATERS MONDAY AFTN. MAY HAVE TO ISSUE SMALL CRAFT ADVISORY FOR THOSE AREAS AS SPEEDS TO BE 20-25 KTS AND SEAS BUILDING TO 7 FEET. CONDITIONS WILL RAPIDLY DETERIORATE MONDAY NIGHT AS ISAAC TRACKS THROUGH THE NORTHERN GULF. BASED ON THE LATEST NHC FORECAST TRACK...NEAR GALE FORCE OR HIGHER CONDITIONS WILL BE POSSIBLE IN COASTAL WATERS FROM MONDAY NIGHT THROUGH TUESDAY NIGHT AS THE STORM MOVES NORTH JUST EAST OF OUR COASTAL WATERS. HAVE NOT MADE SIGNIFICANT CHANGES TO THE FORECAST BUT DID LIMIT SEA HTS TO 15 FEET IN OUTER WATERS. STILL TOO EARLY FOR WATCHES OR ADVISORIES TO BE ISSUED. CONDITIONS TO IMPROVE WED THROUGH THE REST OF THE WEEK AS THE STORM MOVES INLAND AND DISSIPATES. MEFFER Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 348 PM CDT SAT AUG 25 2012 .SYNOPSIS... LATEST SURFACE ANALYSIS SHOWED A TROUGH AXIS FROM MINNESOTA TO WEST TEXAS...ANOTHER TROUGH AXIS FROM MID ATLANTIC TO NORTHEAST GULF AND CYCLONIC CIRCULATION OVER EASTERN CUBA ASSOCIATED WITH ISAAC. PRECIPITABLE WATER PLOTS REVEALED VALUES OF 1.85 INCHES AT LIX AT 18Z AND 2.3 INCHES AT LCH AT 12Z. A WEAK UPPER LEVEL ANTICYCLONIC CIRCULATION OVER THE FORECAST AREA HAS PRODUCED A DESCENT AIR MASS THIS MORNING SUPPRESSING THUNDERSTORM DEVELOPMENT UNTIL THE AFTERNOON HOURS. SURFACE ANALYSIS SHOWED THE RIDGE AXIS FROM THE NORTHEAST CONUS TO CENTRAL MISSISSIPPI. && .DISCUSSION... SURFACE RIDGE AXIS SHOULD REMAIN IN PLACE THROUGH SUNDAY. AS ISAAC MOVES INTO THE EXTREME SOUTHEAST GULF LATE SUNDAY...FLOW WILL BECOME MORE NORTHEASTERLY AND INCREASING BY MONDAY MORNING...ESPECIALLY FOR EAST ZONES. DEWPOINT READINGS IN THE UPPER 50S MAY MIGRATE SOUTHWEST ACROSS PARTS OF SOUTHERN MISSISSIPPI LATE SUNDAY INTO MONDAY. IN ADDITION...THE LOWER LEVELS MOISTURE WILL DECREASE WITH POSSIBLE VALUES RANGING FROM 1.7 INCHES AT BTR TO 1.1 INCHES BY MONDAY. MOREOVER...SUBSIDENCE NORTHWEST OF ISAAC WILL SUPPRESS DEVELOPMENT AS EARLY AS SUNDAY AND CONTINUE INTO MONDAY. DRY AIR WILL LIKELY HEAT UP IN THE AFTERNOON AND WEST ZONES WILL EXPERIENCE HIGHS IN THE MID 90S SUNDAY AND ESPECIALLY MONDAY. FOLLOWING NHC OFFICIAL TRACK OF ISAAC TUESDAY AND WEDNESDAY...WILL CONTINUE TO INTRODUCE CONVECTION OVER COASTAL ZONES TUESDAY...SHOWER LIKELY FOR MISSISSIPPI COASTAL AND COASTAL ZONES EAST OF MISSISSIPPI RIVER TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING. WHILE MID RANGE MODELS HAVE CHANGED TRACKS OF ISAAC WITH GFS NOW WEST AND ECMWF MORE EAST...TIDAL INCREASES OF 2 FEET IS EXPECTED ALONG THE COAST THROUGH THURSDAY WITH NHC TRACK. AS THE ISAAC TRACK NORTH...DRY AIR ENTRAINMENT ON THE BACK SIDE WILL CURTAIL RAIN CHANCES OVER THE AREA THURSDAY INTO FRIDAY. && .MARINE... EASTERLY FLOW WILL BE ON THE INCREASE SUNDAY IN RESPONSE THE TIGHTENING PRESSURE GRADIENT BETWEEN SURFACE RIDGE TO THE NORTHEAST AND TROPICAL STORM ISAAC TRACKING NORTHWEST TOWARDS THE GULF. IN ADDITION...SEAS WILL SLOWLY BUILD BY MONDAY. EXPECT WIND DIRECTION TO GRADUALLY VEER NORTHEAST SUNDAY AND MONDAY WITH WIND SPEEDS INCREASING EAST OF THE MISSISSIPPI AND WELL OFFSHORE. A SMALL CRAFT ADVISORY MAY BE ISSUED FOR THOSE AREAS AS SPEEDS TO BE 20-25 KTS AND SEAS BUILDING TO 7 FEET. CONDITIONS WILL RAPIDLY DETERIORATE MONDAY NIGHT AS ISAAC TRACKS THROUGH THE NORTHERN GULF. BASED ON THE LATEST NHC FORECAST TRACK...NEAR GALE FORCE OR HIGHER CONDITIONS WILL BE POSSIBLE IN COASTAL WATERS FROM EARLY TUESDAY THROUGH WEDNESDAY MORNING AS THE STORM MOVES NORTH JUST EAST OF OUR COASTAL WATERS. CONDITIONS TO IMPROVE WED THROUGH THE REST OF THE WEEK AS THE STORM MOVES INLAND AND DISSIPATES. && .AVIATION... ISOLATED CONVECTION WILL CONTINUE TO DEVELOP NEAR KMCB AND KBTR THROUGH 00Z. AFTER 00Z...THE CONVECTIVE THREAT WILL DIMINISH GREATLY...WITH VFR CONDITIONS EXPECTED AT ALL TERMINALS. AROUND 12Z...A WEAK INVERSION MAY DEVELOP AT KMCB...WHICH COULD ALLOW FOR SOME LIGHT FOG FORMATION. VISIBILITIES MAY FALL TO AROUND 5SM...PRODUCING A PERIOD OF MVFR RESTRICTIONS TO THE AREA. THE INVERSION WILL QUICKLY BREAK BY 13-14Z. THE RISK OF CONVECTION IS MUCH LOWER FOR SUNDAY...AND EXPECT VFR CONDITIONS TO BE FOUND AT ALL TERMINALS. 32 && .DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...MONITORING TROPICAL STORM ISAAC. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 506 AM CDT SUN AUG 26 2012 ...HURRICANE WATCH ISSUED FOR THE MISSISSIPPI GULF COAST AND FOR LOWER ST. BERNARD AND LOWER PLAQUEMINES PARISHES IN LOUISIANA... .SHORT TERM... QUICKLY...SINCE THERE ARE OTHER ISSUES TO DISCUSS...TODAY SHOULD BE A FAIRLY QUIET WEATHER DAY. THIS SHOULD ALLOW AMPLE TIME AND DECENT CONDITIONS FOR PREPARATIONS TO BE COMPLETED. TEMPERATURES WILL REACH INTO THE LOWER 90S TODAY WITH VERY LITTLE CHANCE FOR ANY RAIN AS SURFACE HIGH PRESSURE REMAINS IN PLACE OVER THE AREA. MONDAY IS LOOKING MUCH THE SAME AS ISSAC IS FORECAST TO MOVE INTO THE EXTREME SOUTHEASTERN GULF OF MEXICO BY LATE SUNDAY NIGHT OR EARLY IN THE MORNING HOURS ON MONDAY. WITH ISSAC POSITIONED OFF TO THE SOUTHEAST OF THE FORECAST AREA...WINDS WILL BE OUT OF THE NORTH AND NORTHEAST. THAT WILL AID IN BRINGING SOME DRIER AIR INTO THE AREA AND ALLOW TEMPERATURES TO CLIMB INTO THE LOWER 90S EAST AND SOUTH AND INTO THE MID 90S WEST. LOW RAIN CHANCES EXPECTED THROUGHOUT MOST OF THE DAY MONDAY AS WELL BEFORE CONDITIONS BEGIN TO DETERIORATE FROM EAST TO WEST BEGINNING LATE MONDAY NIGHT. .LONG TERM... NO ON TO THE TOPIC OF MAIN CONCERN...TROPICAL STORM ISAAC. ISAAC IS LOCATED ABOUT 200 MILES TO THE EAST-SOUTHEAST OF KEY WEST AND MOVING TOWARDS THE NORTHWEST AT 18 MPH. THE OVERALL STRUCTURE OF THE STORM CONTINUES TO LOOK RAGGED ON SATELLITE WITH LIMITED DEEP CONVECTION MAINLY OFF TO THE NORTH AND EAST OF THE CENTER. THAT SAID...A RECONNAISSANCE FLIGHT HAS FOUND A SLIGHTLY LOWER PRESSURE OF 995 MB AND WINDS OF 65 MPH. THE NEW FORECAST TRACK FROM THE NATIONAL HURRICANE CENTER CONTINUES TO SHOW ISSAC MOVING GENERALLY IN A WEST-NORTHWEST TO NORTHWEST MOTION TOWARDS THE FLORIDA KEYS AND THE GULF OF MEXICO. IN THE SHORT TERM...THE NEXT 36 HOURS...THE MODEL GUIDANCE IS IN GOOD AGREEMENT ON THAT TRACK. BY EARLY MONDAY MORNING THE HURRICANE CENTER TRACK PUTS ISSAC AROUND 100 MILES TO THE NORTHWEST OF KEY WEST AND INTO THE GULF OF MEXICO. ONCE ISAAC REACHES THE GULF...STRENGTHENING IS FORECAST. AT THAT POINT...MOST OF THE RELIABLE MODEL GUIDANCE IS STILL IN DECENT AGREEMENT WITH THE ECMWF...THE GFS...THE NAM AND THE CMC ALL IN REASONABLE AGREEMENT WITH THE CANADIAN THE FURTHEST WEST. THAT IS WHERE THINGS START TO GET A LITTLE...OFF. THE DIFFERENCES IN THE MODEL RUNS HINGE MOSTLY ON HOW THEY HANDLE THE EVOLUTION OF A SHORTWAVE TROUGH AND HIGH PRESSURE RIDGES TO THE WEST AND THE EAST OF SAID TROUGH. THE GFS AND THE CMC SHOW THE TROUGH BYPASSING ISSAC AND THE TWO RIDGES CLOSING THE GAP BETWEEN THEM LEAVING ISSAC BEHIND TO CONTINUE IN A NORTHWESTWARD MOTION TOWARD THE CENTRAL GULF COAST. THE NAM AND THE ECMWF BOTH LEAVE ENOUGH OF A WEAKNESS OVER THE EASTERN FLORIDA PANHANDLE TO ALLOW FOR A NORTHERLY MOTION TOWARDS THE END OF THE TRACK. DISCOUNTING THE NAM FOR ITS NOTORIOUS ISSUES IN THE TROPICS...AND WITH THE IDEA THAT THE ECMWF WAS ONE OF...IF NOT THE BEST...PERFORMING MODELS IN THE RECENT PAST SOME COMPARISONS WERE DONE ON THE LAST TWO RUNS. THE 12Z RUN YESTERDAY TOOK ISSAC INTO THE FLORIDA PANHANDLE NEAR APALACHICOLA. THE 00Z RUN FROM A FEW HOURS AGO SHOWS A LANDFALL POINT NEAR THE FLORIDA/ALABAMA BORDER. THE 00Z RUN OF THE MODEL DEFINITELY SHOWED A STRONGER ATLANTIC RIDGE WHICH ACCOUNTED FOR THE PUSH FURTHER WEST AS THERE WAS LITTLE DIFFERENCE IN THE EVOLUTION OF THE TROUGH IN THE TWO RUNS. THIS WILL BE WATCHED CLOSELY IN THE NEXT RUN SINCE IT REMAINS ONE OF THE EASTERN MOST MODELS AT THIS POINT. SHOULD IT SHIFT MORE TO THE WEST AND THE OTHER MODELS CONTINUE THEIR WESTWARD SHOWING...ADDITIONAL ADJUSTMENTS TO THE HURRICANE CENTER ARE POSSIBLE. FOR THE TIME BEING HAVE GONE WITH A BLEND OF THE ECMWF AND THE GFS WITH A BIT MORE WEIGHT PLACED ON THE ECMWF SINCE IT IS CLOSER TO THE CURRENT HURRICANE CENTER FORECAST TRACK. THIS WILL BRING THE POSSIBILITY OF TROPICAL STORM CONDITIONS INTO THE AREA ON MONDAY NIGHT ALONG THE EASTERN PARTS OF THE MISSISSIPPI GULF COAST AND TUESDAY MORNING INTO THE NEW ORLEANS METRO AREA. HURRICANE CONDITIONS WILL ALSO BE POSSIBLE...ESPECIALLY BY TUESDAY MORNING ALONG THE MISSISSIPPI COAST. RAIN CHANCES WILL OBVIOUSLY BE DEPENDENT ON THE EVENTUAL TRACK OF ISAAC...AND THEY CURRENTLY REFLECT SOME OF THE UNCERTAINTY IN THE FORECAST TRACK AS MENTIONED IN THE NATIONAL HURRICANE CENTER DISCUSSION. NEEDLESS TO SAY...THIS IS A DEVELOPING AND FLUID SITUATION THAT CAN CHANGE GREATLY OVER THE NEXT 24-36 HOURS. THE BOTTOM LINE IS THAT PARTS OF THE AREA ARE NOW UNDER A HURRICANE WATCH AND IN THOSE AREA PREPARATIONS SHOULD BE RUSHED TO COMPLETION AS QUICKLY AS POSSIBLE. OUTSIDE THE HURRICANE WATCH...RESIDENTS SHOULD CONTINUE TO MONITOR THE LATEST UPDATES ON ISAAC AND BE PREPARED TO TAKE ACTION IF NEEDED. && .AVIATION... VFR CONDITIONS ARE EXPECTED THROUGH 12Z MONDAY WITH THE POSSIBLE EXCEPTION OF SOME MVFR VISIBILITIES DUE TO LIGHT FOG AROUND DAYBREAK. && .MARINE... A HURRICANE WATCH IS NOW IN EFFECT FOR THE MARINE ZONES EAST OF THE MISSISSIPPI RIVER. EXPECT DETERIORATING CONDITIONS ACROSS THE COASTAL WATERS BEGINNING MONDAY AND CONTINUING THROUGH TUESDAY AND WEDNESDAY AS ISAAC IS FORECAST TO STRENGTHEN TO A HURRICANE AS MOVES INTO SOUTHEAST GULF OF MEXICO AND TRACKS TOWARD THE NORTH GULF COAST. THE LATEST FORECAST FROM NHC HAS ISAAC MAKING LANDFALL AS A CATEGORY 2 HURRICANE AROUND MOBILE BAY TUESDAY NIGHT AND EARLY WEDNESDAY. && .PRELIMINARY POINT TEMPS/POPS... MCB 91 67 92 72 / 10 10 10 10 BTR 92 70 94 73 / 10 10 0 10 ASD 91 70 91 75 / 10 10 10 20 MSY 90 74 91 78 / 10 10 10 20 GPT 91 73 90 75 / 10 10 20 30 PQL 91 69 90 75 / 10 10 20 40 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...HURRICANE WATCH UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: LOWER PLAQUEMINES...AND LOWER ST. BERNARD. GM...HURRICANE WATCH UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...LAKE BORGNE...AND MISSISSIPPI SOUND. MS...HURRICANE WATCH UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: HANCOCK...HARRISON...AND JACKSON. GM...HURRICANE WATCH UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...LAKE BORGNE...AND MISSISSIPPI SOUND. Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION...RESENT NATIONAL WEATHER SERVICE NEW ORLEANS LA 506 AM CDT SUN AUG 26 2012 ...HURRICANE WATCH ISSUED FOR THE MISSISSIPPI GULF COAST AND FOR LOWER ST. BERNARD AND LOWER PLAQUEMINES PARISHES IN LOUISIANA... .SHORT TERM... QUICKLY...SINCE THERE ARE OTHER ISSUES TO DISCUSS...TODAY SHOULD BE A FAIRLY QUIET WEATHER DAY. THIS SHOULD ALLOW AMPLE TIME AND DECENT CONDITIONS FOR PREPARATIONS TO BE COMPLETED. TEMPERATURES WILL REACH INTO THE LOWER 90S TODAY WITH VERY LITTLE CHANCE FOR ANY RAIN AS SURFACE HIGH PRESSURE REMAINS IN PLACE OVER THE AREA. MONDAY IS LOOKING MUCH THE SAME AS ISSAC IS FORECAST TO MOVE INTO THE EXTREME SOUTHEASTERN GULF OF MEXICO BY LATE SUNDAY NIGHT OR EARLY IN THE MORNING HOURS ON MONDAY. WITH ISSAC POSITIONED OFF TO THE SOUTHEAST OF THE FORECAST AREA...WINDS WILL BE OUT OF THE NORTH AND NORTHEAST. THAT WILL AID IN BRINGING SOME DRIER AIR INTO THE AREA AND ALLOW TEMPERATURES TO CLIMB INTO THE LOWER 90S EAST AND SOUTH AND INTO THE MID 90S WEST. LOW RAIN CHANCES EXPECTED THROUGHOUT MOST OF THE DAY MONDAY AS WELL BEFORE CONDITIONS BEGIN TO DETERIORATE FROM EAST TO WEST BEGINNING LATE MONDAY NIGHT. .LONG TERM... NO ON TO THE TOPIC OF MAIN CONCERN...TROPICAL STORM ISAAC. ISAAC IS LOCATED ABOUT 200 MILES TO THE EAST-SOUTHEAST OF KEY WEST AND MOVING TOWARDS THE NORTHWEST AT 18 MPH. THE OVERALL STRUCTURE OF THE STORM CONTINUES TO LOOK RAGGED ON SATELLITE WITH LIMITED DEEP CONVECTION MAINLY OFF TO THE NORTH AND EAST OF THE CENTER. THAT SAID...A RECONNAISSANCE FLIGHT HAS FOUND A SLIGHTLY LOWER PRESSURE OF 995 MB AND WINDS OF 65 MPH. THE NEW FORECAST TRACK FROM THE NATIONAL HURRICANE CENTER CONTINUES TO SHOW ISSAC MOVING GENERALLY IN A WEST-NORTHWEST TO NORTHWEST MOTION TOWARDS THE FLORIDA KEYS AND THE GULF OF MEXICO. IN THE SHORT TERM...THE NEXT 36 HOURS...THE MODEL GUIDANCE IS IN GOOD AGREEMENT ON THAT TRACK. BY EARLY MONDAY MORNING THE HURRICANE CENTER TRACK PUTS ISSAC AROUND 100 MILES TO THE NORTHWEST OF KEY WEST AND INTO THE GULF OF MEXICO. ONCE ISAAC REACHES THE GULF...STRENGTHENING IS FORECAST. AT THAT POINT...MOST OF THE RELIABLE MODEL GUIDANCE IS STILL IN DECENT AGREEMENT WITH THE ECMWF...THE GFS...THE NAM AND THE CMC ALL IN REASONABLE AGREEMENT WITH THE CANADIAN THE FURTHEST WEST. THAT IS WHERE THINGS START TO GET A LITTLE...OFF. THE DIFFERENCES IN THE MODEL RUNS HINGE MOSTLY ON HOW THEY HANDLE THE EVOLUTION OF A SHORTWAVE TROUGH AND HIGH PRESSURE RIDGES TO THE WEST AND THE EAST OF SAID TROUGH. THE GFS AND THE CMC SHOW THE TROUGH BYPASSING ISSAC AND THE TWO RIDGES CLOSING THE GAP BETWEEN THEM LEAVING ISSAC BEHIND TO CONTINUE IN A NORTHWESTWARD MOTION TOWARD THE CENTRAL GULF COAST. THE NAM AND THE ECMWF BOTH LEAVE ENOUGH OF A WEAKNESS OVER THE EASTERN FLORIDA PANHANDLE TO ALLOW FOR A NORTHERLY MOTION TOWARDS THE END OF THE TRACK. DISCOUNTING THE NAM FOR ITS NOTORIOUS ISSUES IN THE TROPICS...AND WITH THE IDEA THAT THE ECMWF WAS ONE OF...IF NOT THE BEST...PERFORMING MODELS IN THE RECENT PAST SOME COMPARISONS WERE DONE ON THE LAST TWO RUNS. THE 12Z RUN YESTERDAY TOOK ISSAC INTO THE FLORIDA PANHANDLE NEAR APALACHICOLA. THE 00Z RUN FROM A FEW HOURS AGO SHOWS A LANDFALL POINT NEAR THE FLORIDA/ALABAMA BORDER. THE 00Z RUN OF THE MODEL DEFINITELY SHOWED A STRONGER ATLANTIC RIDGE WHICH ACCOUNTED FOR THE PUSH FURTHER WEST AS THERE WAS LITTLE DIFFERENCE IN THE EVOLUTION OF THE TROUGH IN THE TWO RUNS. THIS WILL BE WATCHED CLOSELY IN THE NEXT RUN SINCE IT REMAINS ONE OF THE EASTERN MOST MODELS AT THIS POINT. SHOULD IT SHIFT MORE TO THE WEST AND THE OTHER MODELS CONTINUE THEIR WESTWARD SHOWING...ADDITIONAL ADJUSTMENTS TO THE HURRICANE CENTER ARE POSSIBLE. FOR THE TIME BEING HAVE GONE WITH A BLEND OF THE ECMWF AND THE GFS WITH A BIT MORE WEIGHT PLACED ON THE ECMWF SINCE IT IS CLOSER TO THE CURRENT HURRICANE CENTER FORECAST TRACK. THIS WILL BRING THE POSSIBILITY OF TROPICAL STORM CONDITIONS INTO THE AREA ON MONDAY NIGHT ALONG THE EASTERN PARTS OF THE MISSISSIPPI GULF COAST AND TUESDAY MORNING INTO THE NEW ORLEANS METRO AREA. HURRICANE CONDITIONS WILL ALSO BE POSSIBLE...ESPECIALLY BY TUESDAY MORNING ALONG THE MISSISSIPPI COAST. RAIN CHANCES WILL OBVIOUSLY BE DEPENDENT ON THE EVENTUAL TRACK OF ISAAC...AND THEY CURRENTLY REFLECT SOME OF THE UNCERTAINTY IN THE FORECAST TRACK AS MENTIONED IN THE NATIONAL HURRICANE CENTER DISCUSSION. NEEDLESS TO SAY...THIS IS A DEVELOPING AND FLUID SITUATION THAT CAN CHANGE GREATLY OVER THE NEXT 24-36 HOURS. THE BOTTOM LINE IS THAT PARTS OF THE AREA ARE NOW UNDER A HURRICANE WATCH AND IN THOSE AREA PREPARATIONS SHOULD BE RUSHED TO COMPLETION AS QUICKLY AS POSSIBLE. OUTSIDE THE HURRICANE WATCH...RESIDENTS SHOULD CONTINUE TO MONITOR THE LATEST UPDATES ON ISAAC AND BE PREPARED TO TAKE ACTION IF NEEDED. && .AVIATION... VFR CONDITIONS ARE EXPECTED THROUGH 12Z MONDAY WITH THE POSSIBLE EXCEPTION OF SOME MVFR VISIBILITIES DUE TO LIGHT FOG AROUND DAYBREAK. && .MARINE... A HURRICANE WATCH IS NOW IN EFFECT FOR THE MARINE ZONES EAST OF THE MISSISSIPPI RIVER. EXPECT DETERIORATING CONDITIONS ACROSS THE COASTAL WATERS BEGINNING MONDAY AND CONTINUING THROUGH TUESDAY AND WEDNESDAY AS ISAAC IS FORECAST TO STRENGTHEN TO A HURRICANE AS MOVES INTO SOUTHEAST GULF OF MEXICO AND TRACKS TOWARD THE NORTH GULF COAST. THE LATEST FORECAST FROM NHC HAS ISAAC MAKING LANDFALL AS A CATEGORY 2 HURRICANE AROUND MOBILE BAY TUESDAY NIGHT AND EARLY WEDNESDAY. && .DECISION SUPPORT... DSS CODE...RED. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...MONITORING TROPICAL STORM ISAAC. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 91 67 92 72 / 10 10 10 10 BTR 92 70 94 73 / 10 10 0 10 ASD 91 70 91 75 / 10 10 10 20 MSY 90 74 91 78 / 10 10 10 20 GPT 91 73 90 75 / 10 10 20 30 PQL 91 69 90 75 / 10 10 20 40 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...HURRICANE WATCH FOR THE FOLLOWING ZONES: LOWER PLAQUEMINES...AND LOWER ST. BERNARD. GM...HURRICANE WATCH FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...LAKE BORGNE...AND MISSISSIPPI SOUND. MS...HURRICANE WATCH FOR THE FOLLOWING ZONES: HANCOCK...HARRISON...AND JACKSON. GM...HURRICANE WATCH FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...LAKE BORGNE...AND MISSISSIPPI SOUND. 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My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 1210 PM CDT SUN AUG 26 2012 .UPDATE... HAVE HAD TO MAKE SOME SIGNIFICANT ADJUSTMENTS TO THE FORECAST GIVEN THE LATEST FORECAST TRACK FOR TROPICAL STORM ISAAC. HAVE INCREASED WINDS ACROSS THE AREA...AS WELL RAIN CHANCES AND QPF VALUES. HAVE BUMPED UP POPS TO CATEGORICAL BEGINNING TUESDAY AND CONTINUING INTO WEDNESDAY NIGHT AS THE TROPICAL CYCLONE MOVES THROUGH THE FORECAST AREA. RAINFALL VALUES HAVE ALSO BEEN INCREASED...WITH QPF IN EXCESS OF 6 INCHES EXPECTED. THESE VALUES MAY INCREASE AS GUIDANCE FROM HPC COMES IN THIS AFTERNOON. 32 && .PREV DISCUSSION... /ISSUED 745 AM CDT SUN AUG 26 2012/ SOUNDING DISCUSSION... NO PROBLEMS WITH THE 12Z FLIGHT. PARTLY CLOUDY SKIES WERE OBSERVED AT RELEASE WITH A FEW LAYER OF ALTOCUMULUS CLOUDS. THESE MID CLOUDS ARE ABOVE 10K FEET. THE PW VALUE REMAINS AT 1.80 INCHES. THERE IS A 7 DEGREE INVERSION JUST BELOW 500 FEET. THE LIFTED INDEX IS NOW INDICATED AT -7.2 INDICATING A CONTINUED UNSTABLE ENVIRONMENT. MEAN LOW LEVEL WINDS FROM THE SURFACE THROUGH 5K FEET ARE FROM THE SOUTHEAST AT 10KTS. FROM 5K TO 10K FEET THE WINDS BACK AND ARE EASTERLY AT JUST UNDER 10KTS. NORTHERLY WINDS ARE IN PLACE FROM 25K FEET THROUGH NEARLY 35K FEET. Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 543 PM CDT SUN AUG 26 2012 ...FOCUS IS ON TROPICAL STORM ISAAC MOVING INTO THE GULF OF MEXICO... .SYNOPSIS... TROPICAL STORM ISAAC NEAR KEY WEST MOVING WNW AT 16 MPH. HIGH PRESSURE AT THE SURFACE EXTENDING FROM CUMBERLAND PLATEAU INTO LOUISIANA AT PRESENT. SUBSIDENCE KEEPING MOST OF THE AREA DRY FOR NOW WITH TEMPERATURES UPPER 80S TO LOWER 90S. && .SHORT TERM... FORECAST PRODUCTS ARE BASED ON 4 PM CDT FORECAST ADVISORY FROM NATIONAL HURRICANE CENTER. TROPICAL STORM AND HURRICANE WARNINGS HAVE BEEN ISSUED FOR PORTIONS OF THE AREA...REPLACING PREVIOUS WATCHES AND EXPANDING THE AREA. ONSET OF TROPICAL STORM CONDITIONS AS EARLY AS MONDAY NIGHT IN LOWER PLAQUEMINES PARISH...TUESDAY MORNING NEAR A SLIDELL TO HOUMA LINE AND SPREADING NORTHWEST. LANDFALL FORECAST OVERNIGHT TUESDAY NIGHT. KEEP UPDATED WITH HURRICANE LOCAL STATEMENTS FOR EXPECTED HAZARDS. 35 && .LONG TERM... EXPECT TROPICAL STORM CONDITIONS TO CONTINUE INTO WEDNESDAY NIGHT BEFORE ISAAC EXITS THE AREA. HIGH PRESSURE WILL GRADUALLY BUILD BACK INTO THE AREA BEHIND THE STORM FOR THE END OF THE WEEK. 35 && .AVIATION... VFR CONDITIONS EXPECTED THROUGH NEXT 24 HOURS...WITH CONDITIONS BEGINNING TO DETERIORATE TOMORROW NIGHT. 35 && .MARINE... ABOUT 24 MORE HOURS OF FAVORABLE WEATHER TO COMPLETE PREPARATIONS FOR ISAAC. AFTER THAT...CONDITIONS WILL DETERIORATE RAPIDLY...ESPECIALLY OVER THE OPEN WATERS. WITH CURRENT FORECAST TRACK...WAVE HEIGHTS IN EXCESS OF 20 FEET WILL BE POSSIBLE OVER THE OPEN WATERS TUESDAY AND TUESDAY NIGHT. CONDITIONS WILL NOT BE FAVORABLE FOR MARINE OPERATIONS UNTIL THE DAYTIME HOURS ON THURSDAY. 35 && .DECISION SUPPORT... DSS CODE...RED. DEPLOYED...3 DEPLOYMENTS BEGINNING MONDAY MORNING. ACTIVATION...GOHSEP ALREADY ACTIVATED...MISSISSIPPI CRISIS ACTION CENTER ACTIVATING MONDAY MORNING. ACTIVITIES...MONITORING TROPICAL STORM ISAAC. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 67 94 72 87 / 10 10 20 50 BTR 70 95 74 88 / 10 10 20 50 ASD 68 93 75 86 / 10 10 40 70 MSY 74 93 77 87 / 10 10 40 70 GPT 70 94 76 85 / 10 20 50 70 PQL 66 93 76 85 / 10 30 50 70 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: ASCENSION...ASSUMPTION...LIVINGSTON...LOWER JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST. BERNARD...LOWER TERREBONNE...NORTHERN TANGIPAHOA...ORLEANS...SOUTHERN TANGIPAHOA...ST. CHARLES...ST. JAMES...ST. JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER TERREBONNE...AND WASHINGTON. TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: EAST BATON ROUGE...EAST FELICIANA...IBERVILLE...POINTE COUPEE...ST. HELENA...WEST BATON ROUGE...AND WEST FELICIANA. GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. MS...TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: AMITE...PIKE...WALTHALL...AND WILKINSON. HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: HANCOCK...HARRISON...JACKSON...AND PEARL RIVER. GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. 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My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 512 AM CDT MON AUG 27 2012 .TROPICAL STORM ISAAC CONTINUES TO MOVE THROUGH THE GULF OF MEXICO... .DISCUSSION... TROPICAL STORM ISAAC IS CURRENTLY MOVING WNW AT 14 MPH THROUGH THE GULF OF MEXICO WITH SUSTAINED WINDS OF 65 MPH. WE ARE STILL ANTICIPATING ISAAC TO BECOME A HURRICANE AT SOME POINT TODAY. THE FORWARD MOTION OF ISAAC IS ALSO EXPECTED TO SLOW DOWN SOME ALLOWING ISAAC TO REACH THAT HURRICANE STATUS. THE LATEST TRACK FROM THE NATIONAL HURRICANE CENTER HAS NOT CHANGED THAT MUCH IT HAS BEEN BUMPED SLIGHTLY TO THE WEST AND MAKE LANDFALL AS A STRONG CATEGORY ONE HURRICANE WITH SUSTAINED WINDS OF 90 MPH. THE ONSET OF TROPICAL STORM CONDITIONS COULD OCCUR AS EARLY AS TONIGHT IN LOWER PLAQUEMINES PARISH...TUESDAY MORNING NEAR A SLIDELL TO HOUMA LINE AND SPREADING NORTHWEST. LANDFALL FORECAST OVERNIGHT TUESDAY NIGHT INTO WEDNESDAY MORNING. TROPICAL STORM FORCE WINDS EXTEND WELL OUT FOR THE CENTER OF ISAAC. HEAVY RAINFALL AMOUNTS OF OVER 6 INCHES CAN BE EXPECTED. HURRICANE AND TROPICAL STORM WARNINGS ARE UP FOR THE ENTIRE FORECAST AREA. SEE HURRICANE LOCAL STATEMENT FOR MORE DETAILS ON WARNINGS AND EXPECTED CONDITIONS. TROPICAL STORM CONDITIONS WILL LINGER INTO WEDNESDAY AND EARLY THURSDAY AS ISAAC EXITS THE REGION. HIGH PRESSURE WILL GRADUALLY BUILD BACK INTO THE AREA BEHIND THE STORM FOR THE END OF THE WEEK. 13/MH && .AVIATION... VFR CONDITIONS ARE EXPECTED FOR ONE MORE DAY BEFORE DETERIORATING PRIMARILY AFTER 06Z TUESDAY AS TROPICAL STORM ISAAC APPROACHES. EXPECT WINDS TO GRADUALLY STRENGTHEN BEGINNING LATER THIS AFTERNOON AND THIS EVENING WITH WINDS NEAR 15 KNOTS FOR MUCH OF THE AREA. 11 && .MARINE... CONDITIONS WILL DETERIORATE RAPIDLY TODAY AS PORTIONS OF ISAAC WILL MOVE INTO THE AREA THIS AFTERNOON AND EVENING. WITH CURRENT FORECAST TRACK...WAVE HEIGHTS IN EXCESS OF 20 FEET WILL BE POSSIBLE OVER THE OPEN WATERS TUESDAY AND TUESDAY NIGHT. CONDITIONS WILL NOT BE FAVORABLE FOR MARINE OPERATIONS UNTIL THE DAYTIME HOURS ON THURSDAY. .DECISION SUPPORT... DSS CODE...RED. DEPLOYED...DEPLOYED TO GOHSEP...NEW ORLEANS...AND MISSISSIPPI CRISIS ACTION CENTER. ACTIVATION...NONE. ACTIVITIES...MONITORING TROPICAL STORM ISAAC. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 93 72 86 74 / 10 10 60 80 BTR 95 73 88 75 / 10 10 70 80 ASD 93 76 85 78 / 10 60 70 90 MSY 93 77 86 78 / 10 50 80 90 GPT 93 76 84 78 / 20 60 80 90 PQL 92 76 84 78 / 30 60 80 90 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: ASCENSION...ASSUMPTION...LIVINGSTON...LOWER JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST. BERNARD...LOWER TERREBONNE...NORTHERN TANGIPAHOA...ORLEANS...SOUTHERN TANGIPAHOA...ST. CHARLES...ST. JAMES...ST. JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER TERREBONNE...AND WASHINGTON. TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: EAST BATON ROUGE...EAST FELICIANA...IBERVILLE...POINTE COUPEE...ST. HELENA...WEST BATON ROUGE...AND WEST FELICIANA. GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. MS...TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: AMITE...PIKE...WALTHALL...AND WILKINSON. HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: HANCOCK...HARRISON...JACKSON...AND PEARL RIVER. GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. 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My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 420 PM CDT MON AUG 27 2012 .SYNOPSIS... TROPICAL STORM ISAAC CONTINUES TO TRACK NORTHWESTWARD AT 14 MPH THROUGH THE CENTRAL GULF. MAXIMUM SUSTAINED WINDS ARE AT 65 MPH. PRESSURE IS DOWN 4 MB FROM PREVIOUS ADVISORY GIVING A MINIMUM PRESSURE OF 984 MB. ISAAC EXPECTED TO BECOME A HURRICANE WITHIN THE NEXT 12 TO 24 HOURS AND IS EXPECTED TO MAKE LANDFALL AS A CATEGORY ONE STORM NEAR THE MOUTH OF THE MISSISSIPPI RIVER LATE TOMORROW NIGHT. && .DISCUSSION... POTENTIAL FOR HEAVY RAINFALL AND WIDESPREAD POWER OUTAGES AS WINDS ARE EXPECTED TO INCREASE TO NEAR HURRICANE FORCE ACROSS SOUTHEAST LOUISIANA AND SOUTHERN COASTAL MISSISSIPPI BY LATE TOMORROW NIGHT. LOOSE SOIL FROM PREVIOUS COUPLE OF MONTHS OF ABOVE NORMAL RAINFALL COMBINED WITH ADDITIONAL HEAVY RAINFALL IS LIKELY TO ALLOW TREES TO BE EASILY UPROOTED FROM STRONG WINDS. ONSET OF TROPICAL STORM CONDITIONS EXPECTED TO BEGIN LATE TONIGHT OVER COASTAL PARISHES OF LA AND COASTAL MISSISSIPPI. TROPICAL STORM FORCE CONDITIONS AND POTENTIALLY HURRICANE CONDITIONS EXPECTED FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING ESPECIALLY SOUTH OF I-12 IN LOUISIANA AND ALONG ALL COASTAL MISSISSIPPI COUNTIES. CONDITIONS EXPECTED TO IMPROVE BY LATE THURSDAY WITH A DRYING TREND EXPECTED TO TAKE HOLD FROM FRIDAY INTO THE WEEKEND AS AN UPPER LEVEL RIDGE BUILDS IN AFTER ISAAC DEPARTS THE REGION. INCREASED POPS FOR THURSDAY AS MODELS ARE SHOWING A SLOWER TRACK NORTHWARD THAN PREVIOUS RUNS FROM REMNANTS OF ISAAC. KEPT 40 TO 50 POPS IN FRIDAY WILL GENERAL 30 TO 40 PERCENTAGE POPS OVER THE WEEKEND. && .AVIATION... FLIGHT CONDITIONS WILL BEGIN DETERIORATING FROM THE SOUTHEAST TO NORTHWEST AFTER 06Z. GUSTS TO 35 KNOTS POSSIBLE AT KHUM...KMSY...KNEW...KASD...KGPT FROM 06Z ONWARD AND CONDITIONS DETERIORATING FROM THERE. 35 && .MARINE... WILL BE UPDATED BASED ON THE NHC 5 PM EDT ADVISORY. CONDITIONS EXPECTED TO DETERIORATE RAPIDLY OVERNIGHT TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... MCB 72 86 74 82 / 10 60 80 90 BTR 73 88 75 83 / 10 70 80 90 ASD 76 85 78 83 / 60 70 90 90 MSY 77 86 78 84 / 50 80 90 90 GPT 76 84 78 83 / 60 80 90 90 PQL 76 84 78 83 / 60 80 90 90 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: ASCENSION...ASSUMPTION...LIVINGSTON...LOWER JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST. BERNARD...LOWER TERREBONNE...NORTHERN TANGIPAHOA...ORLEANS...SOUTHERN TANGIPAHOA...ST. CHARLES...ST. JAMES...ST. JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER TERREBONNE...AND WASHINGTON. FLASH FLOOD WATCH FROM 7 AM TUESDAY TO 7 PM WEDNESDAY FOR THE FOLLOWING ZONES: ASCENSION...ASSUMPTION...EAST BATON ROUGE...EAST FELICIANA...IBERVILLE...LIVINGSTON...LOWER JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST. BERNARD...LOWER TERREBONNE...NORTHERN TANGIPAHOA...ORLEANS...POINTE COUPEE...SOUTHERN TANGIPAHOA...ST. CHARLES...ST. HELENA...ST. JAMES...ST. JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER TERREBONNE...WASHINGTON...WEST BATON ROUGE...AND WEST FELICIANA. TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: EAST BATON ROUGE...EAST FELICIANA...IBERVILLE...POINTE COUPEE...ST. HELENA...WEST BATON ROUGE...AND WEST FELICIANA. GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. MS...FLASH FLOOD WATCH FROM 7 AM TUESDAY TO 7 PM WEDNESDAY FOR THE FOLLOWING ZONES: AMITE...HANCOCK...HARRISON...JACKSON...PEARL RIVER...PIKE...WALTHALL...AND WILKINSON. TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: AMITE...PIKE...WALTHALL...AND WILKINSON. HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: HANCOCK...HARRISON...JACKSON...AND PEARL RIVER. GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 500 AM CDT TUE AUG 28 2012 .DISCUSSION... TROPICAL STORM ISAAC IS SLOWLY STRENGTHENING IN THE GULF HEADING TOWARDS THE LOUISIANA COAST. AS OF 4 AM CST ISAAC HAD MAX SUSTAINED WINDS OF 70 MPH MOVING NORTHWEST AT 12 MPH. THE CENTRAL PRESSURE WAS AT 977 MB WHICH IS VERY IMPRESSIVE FOR A TROPICAL STORM. THE NATIONAL HURRICANE CENTER STILL EXPECTS ISAAC TO BECOME A HURRICANE SOMETIME TODAY BEFORE MAKING LANDFALL LATE TONIGHT INTO EARLY WEDNESDAY MORNING. CURRENT RADAR IMAGERY SHOWS THE FIRST OUTER BANDS FROM ISAAC ARE MOVING ACROSS PLAQUEMINES PARISH. POTENTIAL FOR HEAVY RAINFALL AND WIDESPREAD POWER OUTAGES AS WINDS ARE EXPECTED TO INCREASE TO NEAR HURRICANE FORCE ACROSS SOUTHEAST LOUISIANA AND SOUTHERN COASTAL MISSISSIPPI BY THIS EVENING AND OVERNIGHT INTO WEDNESDAY. LOOSE SOIL FROM PREVIOUS COUPLE OF MONTHS OF ABOVE NORMAL RAINFALL COMBINED WITH ADDITIONAL HEAVY RAINFALL IS LIKELY TO ALLOW TREES TO BE EASILY UPROOTED FROM STRONG WINDS. A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE ENTIRE CWA TO ACCOUNT FOR THE EXTREME RAINFALL TOTALS EXPECTED. FOR THE LATEST INFORMATION FOR TROPICAL STORM ISAAC PLEASE SEE THE LATEST HURRICANE LOCAL STATEMENTS AND NATIONAL HURRICANE CENTER FORECASTS. CONDITIONS EXPECTED TO IMPROVE BY LATE THURSDAY WITH A DRYING TREND EXPECTED TO TAKE HOLD FROM FRIDAY INTO THE WEEKEND AS AN UPPER LEVEL RIDGE BUILDS IN AFTER ISAAC DEPARTS THE REGION. INCREASED POPS FOR THURSDAY AS MODELS ARE SHOWING A SLOWER TRACK NORTHWARD THAN PREVIOUS RUNS FROM REMNANTS OF ISAAC. KEPT 40 TO 50 POPS IN FRIDAY WILL GENERAL 30 TO 40 PERCENTAGE POPS OVER THE WEEKEND. && .AVIATION... CONDITIONS AT THE EACH OF THE TERMINALS WILL DETERIORATE THROUGH THE PERIOD AS ISAAC APPROACHES AND EVENTUALLY MAKES LANDFALL IN THE CWA THIS EVENING. TROPICAL STORM FORCE WINDS WILL DEVELOP DURING THE DAY WITH AT LEAST HURRICANE WIND GUSTS POSSIBLE AT THE MORE COASTAL TAF SITES LATER TODAY AND TONIGHT. RAINBANDS ASSOCIATED WITH ISAAC WILL ALSO INCREASINGLY HAVE AN IMPACT ON THE TERMINALS DURING THE PERIOD. 11 && .MARINE... CONDITIONS WILL DETERIORATE RAPIDLY TODAY AS ISAAC IS EXPECTED TO BECOME A HURRICANE AT SOME POINT TODAY. EXPECT TROPICAL STORM TO HURRICANE CONDITIONS TODAY AND LAST THROUGH TOMORROW. FOR MORE INFORMATION SEE COASTAL WATERS FORECAST AND HURRICANE LOCAL STATEMENT. .DECISION SUPPORT... DSS CODE...RED. DEPLOYED...DEPLOYED TO GOHSEP...MISSISSIPPI CRISIS ACTION CENTER AND NEW ORLEANS EOC. ACTIVATION...DEPLOYMENTS ABOVE WERE ACTIVATED YESTERDAY. ACTIVITIES...MONITORING TROPICAL STORM ISAAC. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 87 74 82 75 / 70 100 100 100 BTR 88 75 83 76 / 70 100 100 90 ASD 85 78 83 78 / 90 100 100 90 MSY 86 78 84 78 / 90 100 100 90 GPT 84 78 83 78 / 90 100 100 90 PQL 84 78 83 76 / 90 100 100 90 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: ASCENSION...ASSUMPTION...LIVINGSTON...LOWER JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST. BERNARD...LOWER TERREBONNE...NORTHERN TANGIPAHOA...ORLEANS...SOUTHERN TANGIPAHOA...ST. CHARLES...ST. JAMES...ST. JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER TERREBONNE...AND WASHINGTON. FLASH FLOOD WATCH UNTIL 7 PM WEDNESDAY FOR THE FOLLOWING ZONES: ASCENSION...ASSUMPTION...EAST BATON ROUGE...EAST FELICIANA...IBERVILLE...LIVINGSTON...LOWER JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST. BERNARD...LOWER TERREBONNE...NORTHERN TANGIPAHOA...ORLEANS...POINTE COUPEE...SOUTHERN TANGIPAHOA...ST. CHARLES...ST. HELENA...ST. JAMES...ST. JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER TERREBONNE...WASHINGTON...WEST BATON ROUGE...AND WEST FELICIANA. TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: EAST BATON ROUGE...EAST FELICIANA...IBERVILLE...POINTE COUPEE...ST. HELENA...WEST BATON ROUGE...AND WEST FELICIANA. GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. MS...FLASH FLOOD WATCH UNTIL 7 PM WEDNESDAY FOR THE FOLLOWING ZONES: AMITE...HANCOCK...HARRISON...JACKSON...PEARL RIVER...PIKE...WALTHALL...AND WILKINSON. TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: AMITE...PIKE...WALTHALL...AND WILKINSON. HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: HANCOCK...HARRISON...JACKSON...AND PEARL RIVER. GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 627 PM CDT TUE AUG 28 2012 .SYNOPSIS... ISAAC HAS STRENGTHENED INTO A CATEGORY ONE HURRICANE. AS OF 4 PM CDT HURRICANE ISAAC HAD MAXIMUM SUSTAINED WINDS OF 80 MPH AND A MINIMUM CENTRAL PRESSURE OF 975 MB. SOME SLIGHT STRENGTHENING IS POSSIBLE BEFORE ISAAC MAKES LANDFALL. ISAAC IS CURRENTLY MOVING NORTHWESTWARD AT 8 MPH. ISAAC IS EXPECTED TO CONTINUE MOVING IN A SIMILAR DIRECTION BUT SLOW ITS FORWARD SPEED SLIGHTLY OVER THE NEXT 48 HOURS. DUE TO THE SLOW MOVEMENT...HEAVY AMOUNTS OF RAIN AS WELL AS A LONG DURATION OF TROPICAL STORM FORCE WINDS ARE EXPECTED TO LAST FOR 36 TO 48 HOURS. WIDESPREAD POWER OUTAGES WITH DOWNED TREES AND POWER LINES LIKELY TO OCCUR DUE TO STRONG WINDS AND VERY WET SOIL. ISAAC IS CURRENTLY LOCATED ABOUT 30 MILES SOUTH OF THE MOUTH OF THE MISSISSIPPI. && .SHORT TERM... HURRICANE ISAAC IS EXPECTED TO MAKE LANDFALL LATE TONIGHT INTO EARLY TOMORROW MORNING AS A CATEGORY ONE STORM NEAR THE MOUTH OF THE MISSISSIPPI RIVER. A FLASH FLOOD WATCH CONTINUES UNTIL THURSDAY MORNING AT 7AM AS ISAAC IS EXPECTED TO TRACK VERY SLOWLY ACROSS SOUTHEASTERN AND EVENTUALLY INTO CENTRAL LOUISIANA THROUGH TOMORROW NIGHT. ISOLATED SHORT LASTING QUICK SPIN UP WEAK TORNADOES POSSIBLE ESPECIALLY ON THE RIGHT FRONT QUADRANT OF THE STORM AS FRICTION IS CREATED UPON LANDFALL. THEREFORE A TORNADO WATCH REMAINS IN AFFECT FOR PARTS OF SOUTHEASTERN LOUISIANA AND PORTIONS OF SOUTHERN LOUISIANA. FOR THE LATEST INFORMATION FOR TROPICAL STORM ISAAC PLEASE SEE THE LATEST HURRICANE LOCAL STATEMENTS AND NATIONAL HURRICANE CENTER FORECASTS. && .LONG TERM... A DRYING TREND IS EXPECTED TO TAKE HOLD BEGINNING THURSDAY NIGHT THROUGH THE WEEKEND AS A LARGE UPPER LEVEL RIDGE BUILDS IN OVER THE EAST- CENTRAL PART OF THE COUNTRY. ABOVE NORMAL TEMPERATURES WITH BELOW NORMAL POPS EXPECTED FROM THE WEEKEND INTO EARLY NEXT WEEK. .AVIATION... HAZARDOUS WEATHER CONDITIONS EXPECTED TO CONTINUE THROUGH THE FORECAST PERIOD. && .MARINE... TROPICAL STORM CONDITIONS WILL CONTINUE OVERNIGHT WITH HURRICANE CONDITIONS LIKELY AS WELL AS ISAAC CONTINUES TO TRACK NORTHWESTWARD TOWARDS THE LOUISIANA COAST. EXPECT TROPICAL STORM TO HURRICANE CONDITIONS TO LAST THROUGH TOMORROW EVENING. FOR MORE INFORMATION SEE COASTAL WATERS FORECAST AND HURRICANE LOCAL STATEMENT. && .PRELIMINARY POINT TEMPS/POPS... MCB 76 82 75 86 / 100 100 100 80 BTR 77 83 76 88 / 100 100 90 70 ASD 80 83 78 88 / 100 100 90 80 MSY 80 84 78 88 / 100 100 90 70 GPT 80 83 78 86 / 100 100 90 70 PQL 80 83 76 86 / 100 100 90 70 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...FLASH FLOOD WATCH UNTIL 7 AM THURSDAY FOR THE FOLLOWING ZONES: ASCENSION...ASSUMPTION...EAST BATON ROUGE...EAST FELICIANA...IBERVILLE...LIVINGSTON...LOWER JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST. BERNARD...LOWER TERREBONNE...NORTHERN TANGIPAHOA...ORLEANS...POINTE COUPEE...SOUTHERN TANGIPAHOA...ST. CHARLES...ST. HELENA...ST. JAMES...ST. JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER TERREBONNE...WASHINGTON...WEST BATON ROUGE...AND WEST FELICIANA. HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: ASCENSION...ASSUMPTION...LIVINGSTON...LOWER JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST. BERNARD...LOWER TERREBONNE...NORTHERN TANGIPAHOA...ORLEANS...SOUTHERN TANGIPAHOA...ST. CHARLES...ST. JAMES...ST. JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER TERREBONNE...AND WASHINGTON. TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: EAST BATON ROUGE...EAST FELICIANA...IBERVILLE...POINTE COUPEE...ST. HELENA...WEST BATON ROUGE...AND WEST FELICIANA. GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. MS...FLASH FLOOD WATCH UNTIL 7 AM THURSDAY FOR THE FOLLOWING ZONES: AMITE...HANCOCK...HARRISON...JACKSON...PEARL RIVER...PIKE...WALTHALL...AND WILKINSON. TROPICAL STORM WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: AMITE...PIKE...WALTHALL...AND WILKINSON. HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: HANCOCK...HARRISON...JACKSON...AND PEARL RIVER. GM...HURRICANE WARNING UNTIL 9 PM MONDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 751 PM CDT TUE AUG 28 2012 .SOUNDING DISCUSSION... NO PROBLEMS WITH THIS EVENINGS 00Z FLIGHT. USED A DE-REALER AND ADDITIONAL HYDROGEN DUE TO STRONG NORTH-NORTHEASTERLY WINDS WITH THE APPROACH OF HURRICANE ISAAC. A LIGHT SHOWER AND OVERCAST SKIES WERE OBSERVED AT RELEASE. MEAN LOW LEVEL WINDS FROM THE SURFACE THROUGH 5K FEET ARE FROM THE NORTHEAST AT 55KTS. FROM 5K TO 10K FEET THE WINDS VEER SOME AND ARE FROM THE EAST-NORTHEAST AT 60KTS. NORTHEASTERLY WINDS REMAIN THROUGH NEARLY 46K FEET. STORM MOTION IS TO THE WEST AT 41KTS. THE COLUMN IS TROPICALLY SATURATED OR NEARLY SATURATED FROM JUST ABOVE THE SURFACE THROUGH 20K FEET OR NEAR 470MB. THE PW VALUE WAS AT 2.79 INCHES. Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOBILE AL 439 AM CDT WED AUG 22 2012 .SHORT TERM...(TODAY THROUGH FRIDAY)TODAY THROUGH TONIGHT...THE REGION WILL REMAIN UNDER THE BASE OF AN UPPER LEVEL TROF OVER THE EASTERN STATES. MEANWHILE...A WEAK SFC TROUGH WILL REMAIN STALLED ACROSS SOUTH CENTRAL ALABAMA. THESE FEATURES COMBINED WITH A MOIST AIRMASS WITH PW VALUES FROM 1.8 TO 2 INCHES WILL LEAD TO ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE COAST LATER THIS MORNING...BEFORE EXPANDING INLAND THROUGH THE LATE AFTERNOON. WHILE WIDESPREAD SEVERE THUNDERSTORMS ARE NOT EXPECTED...AN ISOLATED SEVERE THUNDERSTORM IS POSSIBLE WITH THE MAIN THREAT BEING STRONG WIND GUSTS. A PRELIMINARY ASSESSMENT OF THE WET MICROBURST RISK FOR TODAY INDICATES A HIGH RISK. DUE TO THE SLOW MOVEMENT OF THE STORMS TODAY...LOCALLY HEAVY RAINFALL TOTALS ARE ALSO POSSIBLE ALONG WITH FREQUENT LIGHTNING. 12/DS THIS AFTERNOON`S WET MICROBURST RISK IS LOW. THURSDAY...THE UPPER TROUGH OVER THE EASTERN CONUS FILLS A BIT...BECOMING AN UPPER TROUGH JUST OVER THE ATLANTIC SEABOARD FROM THE MID ATLANTIC REGION SOUTH TO OVER THE NORTHERN GULF OF MEX. A LIGHT NORTH TO NORTHEASTERLY FLOW IN THE BOUNDARY LAYER HELPS TO MAINTAIN THE DRIER AIR THAT HAS MOVED OVER MOST OF THE FA TODAY AND TONIGHT. THE NAM...ECMWF AND HIRES MODELS MAINTAIN A BIT MORE MOISTURE OVER SOUTHEASTERN-MOST SECTIONS OF THE FA THAN THE GFS. FOR THE STATISTICAL GUIDANCE...THIS TRANSLATES INTO ISOLATED POPS ALONG THE NW FL COASTAL COUNTIES AND AREA COASTAL WATERS. WITH THE AREA UNDER THE SUBSIDENCE SIDE OF THE EAST COAST TROUGH...AM TENDING TO LEAN TOWARDS THE DRIER GFS FOR POPS...THOUGH NOT QUITE AS WARM WITH POPS DUE TO THE ADDED MOISTURE. THURSDAY NIGHT...SHORTWAVE ENERGY PASSING EAST OVER THE SOUTHERN/CENTRAL PLAINS PUSHES AN UPPER RIDGE OVER THE LOWER MISS RIVER VALLEY...HELPING TO SQUASH ANY PRECIP DEVELOPMENT. A SURFACE RIDGE BUILDS ALONG THE ATLANTIC SEABOARD FROM NEW ENGLAND SW TO OVER THE S-ERN CONUS. AN UPPER TROUGH FORMS OVER THE MID ATLANTIC REGION OF THE CONUS FROM SOME SHORTWAVE ENERGY. THIS RESULTS IN A GENERAL NORTHEASTERLY FLOW OVER THE FA AND TEMPS BELOW SEASONAL. FRIDAY...MOST OF THE GUIDANCE IS ADVERTISING THE UPPER TROUGH OVER THE MID-ATLANTIC REGION ORGANIZING INTO A CLOSED SYSTEM...HELPING TO PUSH THE SURFACE RIDGE ALONG THE EAST COAST NORTHEASTWARD...BRINGING A MORE EASTERLY FLOW TO THE SOUTHEASTERN CONUS AND MOISTURE OF THE ATLANTIC OCEAN. THE NAM TAKES THIS INCOMING MOISTURE TO HEART... ADVERTISING LOW END CHANCE POPS IN THE STATISTIC GUIDANCE...WHILE THE OTHER GUIDANCE IS ADVERTISING ISOLATED OR NONE. WENT WITH ISOLATED AT MOST...MAINLY OVER THE SOUTHWESTERN-MOST SECTION OF THE FA OR MARINE AREAS...WITH THE MORE ORGANIZED MOISTURE FLOW OFF THE GULF OVER THE LOWER MISS RIVER VALLEY. FOR TEMPS...WENT AROUND SEASONAL. IT`S AT THIS TIME...ALL THE GUIDANCE IS ADVERTISING THE APPEARANCE IF ISSAC ON THE SCOPE...MOVING TO A POINT APPROACHING CUBA. .LONG TERM...(FRIDAY NIGHT ON)FRIDAY NIGHT BEGINS WITH ISAAC APPROACHING CUBA...AROUND THE BASE OF AN UPPER RIDGE OVER THE WESTERN ATLANTIC...OFF THE CAROLINA COAST. A WEAKLY ORGANIZED UPPER SYSTEM OVER THE CAROLINAS...AN UPPER RIDGE STRETCHING EAST OVER MEX TO THE WESTERN GULF OF MEX. ITS A WEAK UPPER TROUGH OVER THE EASTERN GULF OF MEX THAT IS MAKING FOR AN INTERESTING FORECAST IN THE EXTENDED. THE GFS/NAM/CANADIAN MAINTAIN THIS UPPER TROUGH OVER THE EASTERN GULF INTO THE WEEKEND...ALLOWING ISSAC TO MOVE NORTH OVER THE FL PENINSULA. THE ECMWF BUILDS THE WESTERN ATLANTIC RIDGE WEST...OVER THE GULF OF MEX...STALLING ISAAC OVER CUBA THROUGH THE WEEKEND. CONCENSUS IS TO THROUGH CANADIAN OUT THE DOOR. CURRENT FORECAST TAKES ISSAC TO NEAR KMIA BY SUNDAY NIGHT...MORE IN LINE WITH THE GFS INTERPRETATION OF THINGS. EXTRAPOLATING THIS COURSE OF ACTION FARTHER OUT IN TIME...ISSAC HEADS NORTH OVER THE FL PENINSULA THROUGH THE LAST COUPLE OF DAYS OF THE EXTENDED. FOR THE FORECAST...THIS MEANS A SLOWLY INCREASING CHANCE FOR POPS THROUGH THE EXTENDED...WITH THE BEST CHANCE BEING TUESDAY AND WEDNESDAY. TEMPS...AROUND SEASONAL DURING THE DAY...SEVERAL DEGREES BELOW SEASONAL MODERATING TO SEASONAL. && .AVIATION...(08/12Z ISSUANCE)...PRIMARILY VFR CONDITIONS EXPECTED THROUGH MUCH OF THE MORNING HOURS. HOWEVER...SHOWERS AND THUNDERSTORMS WILL INCREASE IN COVERAGE BY LATE MORNING AND CONTINUE THROUGH THE AFTERNOON HOURS. MVFR/IFR CONDITIONS ARE POSSIBLE IN AND AROUND TSRA DURING MAINLY THE AFTERNOON AND EARLY EVENING HOURS. 12/DS && .MARINE...HIGH PRESSURE WILL CONTINUE OVER MUCH OF THE EASTERN AND NORTH CENTRAL GULF THROUGH SUNDAY. A LIGHT TO MODERATE WEST TO SOUTHWEST WIND WILL CONTINUE THROUGH EARLY NEXT WEEK. WINDS AND SEAS WILL BE HIGHER IN AND AROUND SHOWERS AND THUNDERSTORMS THROUGH EARLY NEXT WEEK. THE SHOWERS AND THUNDERSTORMS WILL BE MOST NUMEROUS DURING THE MORNING HOURS. 12/DS Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOBILE AL 327 PM CDT WED AUG 22 2012 .SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...THE FRONT THAT PASSED EARLIER IS PULLING OFFSHORE AND SHOWING SIGNS OF EARLY FRONTOLYSIS. CONVECTION HAS DECREASED MUCH AND CLOUD TOPS HAVE WARMED THEN DISSIPATED AS EVIDENCED BY IR AND SATELLITE IMAGERY. UPPER TROUGH IS SITUATED OVER THE REGION EXTENDING NORTH INTO QUEBEC PROVINCE...AND WILL DAMPEN OUT OVER THE NEXT 48 TO 72 HOURS GETTING REPLACED BY A RIDGE WITH A SMALL BREAK JUST UNDER US OVER THE GULF. THE PRESENCE OF SAID FEATURE SHOULD KEEP US PRETTY DRY INTO THE WEEKEND. IT WILL ALSO GET US PRETTY WARM WITH MAXIMA IN THE LOWER 90S. AS FOR THE VERTICAL PROFILE...THE FORECAST SOUNDINGS AND CROSS SECTIONS INDICATE OVERALL STABILIZING TREND. USED GFS GUIDANCE WITH LITTLE DEVIATION ESPECIALLY POPS. TEMPERATURE WENT A DEGREE OR TWO HIGHER FOR THIS CYCLE THAN LAST. 77/BD .LONG TERM (SATURDAY THROUGH TUESDAY )...NO CHANGES. WAVENUMBER 5 PROG INDICATES A BREAKDOWN IN THE RIDGE OVER WESTLANT. NO BAROCLINIC FEATURES ARE INDICATED IN THE OFFING...THE RAIN CHANCES WILL DECLINE AND THE TEMPERATURES WILL CLIMB. THERE IS A WEAK UPPER SYSTEM OVER THE CAROLINAS AND AN UPPER RIDGE FROM OVER MEXICO TO THE WESTERN GULF BY DAY 4. ITS A WEAK UPPER TROUGH OVER THE EASTERN GULF OF MEX THAT IS MAKING FOR AN INTERESTING FORECAST IN THE EXTENDED. THE GFS/NAM/CANADIAN MAINTAIN THIS UPPER TROUGH OVER THE EASTERN GULF INTO THE WEEKEND...ALLOWING ISSAC TO MOVE NORTH OVER THE FL PENINSULA. THE ECMWF BUILDS THE WESTERN ATLANTIC RIDGE WEST...OVER THE GULF. FOR THE EXTENDED FORECAST...THIS MEANS A SLOWLY INCREASING CHANCE FOR POPS THROUGH THE EXTENDED...WITH THE HIGHEST CHANCE BEING TUESDAY NEXT WEEK ANTICIPATING A RETURN TO THE SEABREEZE. TEMPS AROUND SEASONAL. && .AVIATION...(08/12Z ISSUANCE)...PRIMARILY VFR CONDITIONS EXPECTED THROUGH THE REST OF THE DAY. MVFR/IFR CONDITIONS POSSIBLE IN AND AROUND IS ISOLD SHRA/TSRA THURSDAY MORNING LATE. 77/BD && .MARINE...LITTLE CHANGE TO FORECAST. USED MODEL OUTPUT FROM SIMULATING WAVES NEARSHORE (SWAN) TO FORECAST SEAS. SURFACE HIGH WILL CONTINUE TO DOMINATE THE EASTERN AND NORTH CENTRAL GULF THROUGH SUNDAY. A LIGHT TO MODERATE WIND FROM THE WEST AND SOUTHWEST WILL CONTINUE THROUGH EARLY NEXT WEEK. WINDS AND SEAS WILL BE HIGHER IN AND NEAR SHOWERS AND THUNDERSTORMS THROUGH EARLY NEXT WEEK. THE SHOWERS AND THUNDERSTORMS WILL BE MOST NUMEROUS DURING THE MORNING AND PROGRESSIVELY FURTHER OFFSHORE. 77/BD Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOBILE AL 452 AM CDT THU AUG 23 2012 .SHORT TERM...(TODAY THROUGH SATURDAY)FOR TODAY THROUGH TONIGHT... WEAKENING SFC BOUNDARY REMAINS OFFSHORE TO THE SOUTH OF THE FCST AREA...BUT LIFT ALONG AND NORTH OF THE BOUNDARY IS RESULTING IN ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS OVER THE FLORIDA COASTAL WATERS THIS MORNING. WATER VAPOR IMAGERY SHOWING A SHARP MOISTURE GRADIENT ACROSS THE FAR EASTERN SECTIONS OF THE FCST AREA...WITH VERY DRY AIRMASS OVER MOST OF THE REGION AND MORE MOIST TOWARD FLORIDA PANHANDLE COUNTIES. THIS INCREASED MOISTURE OVER THE SOUTHEASTERN ZONES COMBINED WITH THE FRONTAL BOUNDARY JUST OFFSHORE...ALONG WITH DAYTIME HEATING AND A WEAK SEA BREEZE CIRCULATION...WILL RESULT IN ISOLATED TO SCATTERED SHOWERS AND STORMS TO DEVELOP ALONG AND JUST INLAND FROM THE COAST TODAY. MOST OF THE ACTIVITY IS EXPECTED TO OCCUR OVER THE WESTERN FLORIDA PANHANDLE. LITTLE TO NO RAIN CHANCES OVER INTERIOR PORTIONS OF FCST AREA WHERE THE MUCH DRIER AIR DOMINATES. TONIGHT...ANY ISOLATED SHOWERS AND STORMS THAT PERSIST WILL BE SOUTH OVER THE NORTHERN GULF...WITH NO RAINFALL EXPECTED OVER LAND AREAS. SKIES WILL REMAIN PARTLY CLOUDY OR MOSTLY CLEAR ACROSS THE REGION THROUGH TONIGHT. A WEAK WIND FLOW PATTERN WILL PERSIST OVER THE REGION... WITH LIGHT NORTHEASTERLY WINDS EXPECTED TODAY AND THEN LIGHT AND VARIABLE TONIGHT. HIGH TEMPS TODAY RISING INTO THE LOWER 90S ACROSS MOST OF THE FCST AREA...EXCEPT FOR ALONG AND JUST INLAND FROM THE COAST...WHERE UPPER 80S ARE MORE LIKELY. MIN TEMPS TONIGHT EXPECTED TO BE IN THE LOW TO MID 60S INTERIOR AND LOWER 70S ALONG THE IMMEDIATE COAST. 12/DS THIS AFTERNOON`S WET MICROBURST RISK IS LOW. FOR FRIDAY...THE SEMI-ORGANIZED LOW OVER THE CAROLINAS SHIFTS NORTHEAST...PUSHING THE CENTER OF THE SURFACE RIDGE OVER THE MID- ATLANTIC REGION NORTHEAST. THIS WILL SHIFT THE RIDGELINE STRETCHING SOUTHWEST ALONG THE EASTERN SEABOARD NORTHEAST NORTHEAST A BIT...WITH THE RESULT BEING SOUTHEAST FLOW OFF THE GULF STRENGTHENING OVER THE LOWER MISS RIVER VALLEY...AND LOW LEVEL FLOW BECOMING EAST TO SOUTHEAST OVER THE FA. THIS WILL HELP TO BEGIN TO INCREASE MOISTURE LEVELS OVER THE FA. WITH THE SURFACE BOUNDARY HANGING TOUGH OVER THE MARINE FA...A FEW TSRA MAY AFFECT NEAR COASTAL AREAS...BUT AM EXPECTING A GENERALLY RAIN-FREE DAY OVER THE LAND PART OF THE FA. TEMPS AROUND SEASONAL ARE EXPECTED. FRIDAY NIGHT...NO REAL SIGNIFICANT CHANGE NOTED IN THE GUIDANCE... OTHER THAN ISSAC MOVING OVER THE SOUTHWESTERN CARIBBEAN. WITH BEST MOISTURE INFLUX OVER THE FA BEING ALONG THE COAST AND SOUTHWESTERN SECTIONS OF THE CONUS...OVERNIGHT TEMPS ARE AGAIN EXPECTED TO DROP TO SEVERAL DEGREES BELOW SEASONAL OVER MOST OF THE FA. SATURDAY...THE UPPER LOW OVER THE MID-ATLANTIC REGION MEANDERS A BIT NORTHEAST...TAKING THE EAST-COAST SURFACE RIDGE A BIT FARTHER NORTHEAST WITH IT. THE RESULT IS A BIT MORE ORGANIZED SOUTHEASTERLY FLOW OVER MOST OF THE FA...BRINGING IN A BIT MORE MOISTURE. STILL FEEL A BIT TOO DRY FOR TSRA...ESPECIALLY WITH AN UPPER LOW THAT HAS MIGRATED TO OVER THE LOWER MISS RIVER VALLEY. TEMPS AGAIN EXPECTED TO BE AROUND SEASONAL. .LONG TERM...(SATURDAY NIGHT ON)THIS IS WHERE THE FORECAST GETS INTERESTING. IN ADDITION TO THE UPPER HIGH OVER/NEAR THE LOWER MISS RIVER VALLEY...ANOTHER UPPER RIDGE STRETCHING WEST TOWARDS THE FL PENINSULA FROM THE OPEN ATLANTIC. THE UPPER TROUGH REMAINS OVER.NEAR THE FL PENINSULA...AND IT`S THE DANCE BETWEEN THESE THREE UPPER FEATURES THROUGH THE WEEKEND INTO THE COMING WEEK THAT STEERS ISSAC...NEAR CUBA BY SATURDAY NIGHT...IN ITS DANCE IN ITS JOURNEY IN THE EXTENDED. THE MAIN PLAYERS IN THE EXTENDED ARE IN BETTER AGREEMENT AT THE BEGINNING OF THE EXTENDED...THOUGH THE ECMWF IS A BIT FARTHER WEST WITH THE STEERING FEATURES BY A SCOOCH ON THE SYNOPTIC SCALE. SATURDAY NIGHT INTO MONDAY MORNING...ISAAC TAKES A PATH TO OVER CENTRAL CUBA BEFORE HEADING NNW IN THE UPPER TROUGH OVER/NEAR THE FL PENINSULA. WITH THE UPPER FEATURES IN MORE AGREEMENT...SPEED HAS ALSO COME MORE IN LINE...EVEN THE SPEED-DEMON CANADIAN. THE GFS...ECMF...AND CANADIAN HAVE ISSAC OVER/NEAR THE SOUTHERN FL PENINSULA BY MONDAY MORNING...WITH THE ECMWF AND GFS ADVERTISING A POSITION OVER THE FL KEYS. FOR THE FA...THIS MEANS THE SE LOW LEVEL FLOW BECOMING MORE NORTHEASTERLY BY MONDAY MORNING...SHUTTING OFF THE GULF MOISTURE...THOUGH BRINGING IN TROPICAL ATLANTIC MOISTURE. BY TUESDAY MORNING...THE ECMWF AND GFS HAVE ISSAC OFF THE GULF COAST OF THE FL PENINSULA...WITH THE ECMWF ADVERTISING A MORE WESTERLY POSITION. BOTH ARE AT THE SAME GENERAL LATITUDE AT THIS TIME...PRETTY GOOD AGREEMENT WEST OF TAMPA BAY. THE CANADIAN HAS TAKEN ISSAC MORE QUICKLY NORTHWARD...PUTTING ISAAC OVER SOUTHERN GA. WITH THE CANADIAN GENERALLY A POOR PERFORMER...HAVE DROPPED IT FROM CONSIDERATION. FOR THE FA...BY TUESDAY MORNING...THE FA IS UNDER MODERATE TO STRONG NNE TO NE LOW LEVEL FLOW...WITH THE STRONGEST WINDS BEING OVER THE SOUTHEASTERN CORNER OF THE MARINE FA. DEPENDING UPON HOW ISAAC GROWS...AM EXPECTING TO BEGIN SEEING RAIN-BANDS FROM ISAAC MOVING OVER THE MARINE FA TO LAND AREAS. BY WEDNESDAY MORNING...THE REAL FORECAST PROBLEM LIES. THE ECMWF IS ADVERTISING ISSAC SOUTH OF THE WESTERN FLORIDA PENINSULA...WHILST THE GFS IS ADVERTISING A POSITION OVER THE AL/FL/GA JUNCTURE. BIG DIFFERENCES IN WINDS/RAIN AND TEMPS. CONCENSUS IS TO LEAN THE FORECAST TOWARDS THE GFS SOLUTION...WITH ISAAC AFFECTING MAINLY EASTERN SECTIONS OF THE FA TUESDAY AND TUESDAY NIGHT BEFORE MOVING OFF TUESDAY NIGHT INTO WEDNESDAY. FROM THERE...THE USUAL POST TROPICAL SYSTEM DRY-OUT. && .AVIATION...(23/12Z ISSUANCE)...VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH CLOUD BASES AT MID/HIGH LEVELS. LIGHT EAST TO NORTHEAST FLOW EARLY TODAY...BECOMING MORE SOUTHEAST TO SOUTHERLY BY THIS AFTERNOON (23/21Z). WINDS BECOME LIGHT AND VARIABLE TONIGHT. MAY BE AN ISOLATED SHRA/TSRA OVER WESTERN FLORIDA PANHANDLE REGION TODAY...BUT COVERAGES TOO WIDESPREAD TO INCLUDE IN TERMINAL FCSTS ATTM. 12/DS && .MARINE...LITTLE CHANGE IN FCST IN THE SHORT TERM...BUT WINDS AND SEAS EXPECTED TO BEGIN INCREASING AT THE VERY END OF THE FCST PERIOD AS AFFECTS OF ISAAC POSSIBLY BEGIN TO IMPACT THE MARINE AREA IF THE CURRENT FCST FOR THE STORM HOLDS. ANY SIGNIFICANT AFFECTS...IF THEY DO OCCUR...WILL BE JUST BEYOND THIS FCST PACKAGE TIME PERIOD. IN THE MEANTIME...A WEAKENING STATIONARY FRONT OVER THE COASTAL WATERS DISSIPATES BY THE EARLY PART OF THE WEEKEND AS A HIGH PRESSURE RIDGE NOSES IN FROM THE NORTHEAST. THIS WILL RESULT IN A LIGHT GENERALLY EAST TO SOUTHEAST WIND FLOW THROUGH SATURDAY. WINDS BECOMING MORE EAST AND NORTHEASTERLY SUNDAY THROUGH LATE MONDAY WHILE GRADUALLY INCREASING...ALONG WITH SLOWLY BUILDING SEAS. ISOLATED TO SCATTERED SHRA/TSRA ARE EXPECTED OVER THE NEAR SHORE WATERS AND COASTAL BAYS AND WATERWAYS FOR THE NEXT COUPLE OF DAYS...MOST NUMEROUS OFFSHORE. THE GFS AND ECMWF ARE COMING INTO BETTER AGREEMENT WITH ISAAC IMPACTING THE EASTERN GULF OF MEXICO JUST BEYOND THE FCST PERIOD FOR THIS MARINE PACKAGE. OFFICIAL NHC FCST...WHICH IS IN CLOSEST AGREEMENT WITH THE GFS...BRINGS ISAAC INTO THE EASTERN GULF TO THE WEST OF TAMPA AS A CAT1 HURRICANE BY 28/06Z (MONDAY NIGHT). THE GFS WIND FIELD WAS USED FOR THE WIND FCST THIS PACKAGE AS IT WAS IN GOOD AGREEMENT WITH NHC FCST. WINDS/SEAS ARE EXPECTED TO BE APPROACHING SCA CRITERIA BY MONDAY NIGHT. MARINE INTERESTS SHOULD MONITOR THE PROGRESS OF ISAAC CAREFULLY OVER THE NEXT SEVERAL DAYS...AS IMPACTS LIKELY TO INCREASE ACROSS THE MARINE AREA EARLY TO MIDDLE PART OF NEXT WEEK. 12/DS Link to comment Share on other sites More sharing options...
My Weather Today Posted August 29, 2012 Share Posted August 29, 2012 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOBILE AL 418 PM CDT THU AUG 23 2012 .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...CHART FEATURES INCLUDE REMAINS OF A FRONT OFFSHORE IS WEAKENING INTO A TROUGH WHILE A STRENGTHENING RIDGE OVER THE PIEDMONT BRINGS NORTHEAST WINDS INTO THE REGION. 500 MB TROUGH OVER THE REGION. WEAK VORTLOBES TRANSIT THE AREA BUT THE PRECIPITABLE WATER IS LESS THAN 1.5 INCHES FOR THE NEXT 48 HOURS AND LI IS ABOUT +1. BASICALLY CLEAR AND SEVEN FOR THE NEXT 60 HOURS. THE SATELLITE IMAGERY IN THE WATER VAPOR BAND IS SHOWING A SHARP MOISTURE GRADIENT ACROSS THE FAR EASTERN SECTIONS OF THE FCST AREA...WITH VERY DRY AIR OVER THE REGION AND MORE MOIST TOWARD CENTRAL FLORIDA PANHANDLE. VERTICAL PROFILE: THE RAOB AND FORECAST SOUNDINGS INDICATE A DRY ATMOSPHERE WITH A TEMPERATURE PROFILE APPROXIMATING MOIST ADIABATIC WHICH MEANS VERY STABLE WITH LITTLE CHANCE OF CONVECTION. MODELS WERE CLOSE ON THE NEAR TERM. WE HAD ONLY A DEGREE OR TWO DEVIATION FROM GUIDANCE AND A SMALL AMOUNT OF THAT WAS TO PROVIDE CONSISTENCY WITH NEIGHBORS. /77 .LONG TERM (SUNDAY THROUGH WEDNESDAY )...NO CHANGES TO FORECAST. UPPER HIGH OVER/NEAR THE LOWER MISSISSIPPI VALLEY...ANOTHER UPPER RIDGE EXTENDING WEST TOWARDS THE FL PENINSULA FROM THE OPEN ATLANTIC. THE UPPER TROUGH REMAINS NEAR THE FLORIDA PENINSULA. THESE THREE UPPER FEATURES WILL BE THE MAJOR INFLUENCE ON THE TRACK OF ISSAC. INTO MONDAY MORNING...THE GFS AND ECMWF HAVE ISSAC OVER THE SOUTHEAST GULF...ALBEIT WITH POSITION OF THE ECMWF ABOUT 200 MILES SOUTH OF THE GFS. EITHER WOULD INDICATE THE LOW LEVEL FLOW BECOMING MORE EASTERLY BY THEN WHICH WOULD SHUT OFF THE GULF MOISTURE AND BRINGING IN TROPICAL ATLANTIC MOISTURE. BY TUESDAY MORNING...GFS HAS ISSAC OFF THE GULF COAST OF THE FLORIDA PENINSULA...WHILE THE ECMWF CALCULATES A POSITION ABOUT 125 MILES SOUTH OF VERMILLION BAY LOUISIANA. ECMWF WOULD HAVE THE REGION UNDER MODERATE TO STRONG SOUTHEAST WINDS BECOMING EAST TO NORTHEAST WITH STRONGEST WINDS OVER THE SOUTHWESTERN CORNER OF THE REGION BY WEDNESDAY MORNING. THIS WOULD BRING CONSIDERABLE RAINFALL PROSPECTS AS WELL. CONVERSELY THE GFS BRINGS ON A STRONG NORTH WIND WITH LESS RAIN. THIS IS WHERE INCREASING UNCERTAINTY IN THE FORECAST APPEARS. A LOT IS ALSO DEPENDING ON THE SIZE OF ISAAC. GIVEN THE DISAGREEMENT WITH THE EXTENDED MODEL OUTPUTS THIS FAR OUT...THERE IS LOW CONFIDENCE IN HOW THE EVOLUTION OF THIS EVENT WILL EVENTUALLY UNFOLD. /77 && .MARINE...A WEAK RIDGE OF HIGH PRESSURE OVER THE AREA WILL MAINTAIN A LIGHT EAST TO SOUTH WIND FLOW THROUGH SATURDAY. WINDS WILL BECOME MORE EAST AND NORTHEASTERLY SUNDAY THROUGH LATE MONDAY WHILE GRADUALLY INCREASING...ALONG WITH SLOWLY BUILDING SEAS. THE NATIONAL HURRICANE CENTER CALLS FOR TROPICAL STORM ISAAC TO BECOME A HURRICANE AS IT LIFTS NORTHWEST ACROSS THE FLORIDA STRAITS LATE SUNDAY...TRACKING NORTHWEST ACROSS THE GULF OF MEXICO MONDAY INTO TUESDAY. EXPECT WINDS AND SEAS TO TREND HIGHER ACROSS THE MARINE AREA EARLY NEXT WEEK. STAY TUNED TO THE LATEST FORECASTS AND ADVISORIES ISSUED BY THE NATIONAL HURRICANE CENTER ON TROPICAL STORM ISAAC. Link to comment Share on other sites More sharing options...
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