WilkesboroDude Posted April 6, 2013 Share Posted April 6, 2013 ...DISCUSSION... MULTI-DAY SEVERE WEATHER EPISODE IS EXPECTED ACROSS PARTS OF THE S-CNTRL AND PERHAPS EVENTUALLY THE SERN CONUS IN ASSOCIATION WITH AN UPPER-LEVEL TROUGH PROGRESSING EWD FROM THE WRN CONUS. PRECEDING DAYS OF SLY RETURN FLOW OF A MODIFIED GULF AIR MASS BENEATH A STOUT EML SHOULD YIELD AT LEAST MODERATELY UNSTABLE CONDITIONS AHEAD OF THE PLAINS DRYLINE BEING OVERTAKEN BY A COLD FRONT THAT WILL PROGRESS EWD DURING THE PERIOD. WITH STRENGTHENING OF MID-LEVEL SWLYS AS THE SPEED MAX EJECTS FROM THE BASE OF THE WRN CONUS TROUGH...SETUP SHOULD BE FAVORABLE FOR SUPERCELLS AND AN EVENTUAL SQUALL LINE WITH ALL MODES OF SEVERE /SOME SIGNIFICANT/ PROBABLE DURING D4-5. STILL...CONFIDENCE IS ONLY AVERAGE FOR HIGHLIGHTING CORRIDORS OF ENHANCED COVERAGE PROBABILITIES /AOA 30 PERCENT/ AS MODELS REMAIN MODERATELY DIVERGENT WITH TIMING OF THE KEY SYNOPTIC FEATURES DURING THIS TIME FRAME. DISCREPANCIES WITH EVOLUTION OF THE UPPER-LEVEL TROUGH AND ATTENDANT COLD FRONT BECOME EVEN GREATER BY D6-7...WHERE SEVERE WEATHER AREAS COULD EVENTUALLY BE WARRANTED IN PARTS OF THE SOUTHEAST. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted April 6, 2013 Author Share Posted April 6, 2013 NWS Blacksburg:This system has the potential for a qlcs with possibly strong to severe thunderstorms as well. Will mention this in the severe weather potential statement this morning. At least one day of 80f looks possible for the Southside/NC Piedmont next week. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted April 6, 2013 Author Share Posted April 6, 2013 ALERT: Widespread Tornado Threat Possible http://www.weather.com/news/tornado-central/severe-outbreak-south-20130404 Link to comment Share on other sites More sharing options...
WilkesboroDude Posted April 7, 2013 Author Share Posted April 7, 2013 Accuweather: By Wednesday, the severe weather is forecast to reach some of the Mississippi Valley states and may organize into a solid line of thunderstorms, known as a squall line. Link to comment Share on other sites More sharing options...
Disc Posted April 7, 2013 Share Posted April 7, 2013 Accuweather: This is for the mid-West and has nothing to do with SE.. If anything in the SE, it'll likely be some sort of squall line pushing through mid/late week. Link to comment Share on other sites More sharing options...
Jon Posted April 7, 2013 Share Posted April 7, 2013 This is for the mid-West and has nothing to do with SE.. If anything in the SE, it'll likely be some sort of squall line pushing through mid/late week. Bingo. Here, I'll make it easy: http://www.americanwx.com/bb/index.php/topic/39881-significant-severe-weather-threats-48-10/page-6 /lockthread Link to comment Share on other sites More sharing options...
WilkesboroDude Posted April 7, 2013 Author Share Posted April 7, 2013 This is for the mid-West and has nothing to do with SE.. If anything in the SE, it'll likely be some sort of squall line pushing through mid/late week. You guys are going to have to chill. Our weather comes from the west I was just tracking the origins. SE (TN/MS) now highlighted squall line or w/e...could get some discrete storms out ahead of it. Link to comment Share on other sites More sharing options...
jburns Posted April 7, 2013 Share Posted April 7, 2013 You guys are going to have to chill. Our weather comes from the west I was just tracking the origins. SE (TN/MS) now highlighted squall line or w/e...could get some discrete storms out ahead of it. Actually you need to chill. This thread is useless. If something develops on the 9th an obs thread can be started then. Until then this should be discussed in the main April severe thread. By now you should have realized that no one else has posted and begun the search for the reason. A hint. When everyone else has the opposite opinion of yours, you are most likely wrong. Link to comment Share on other sites More sharing options...
WNCwx Posted April 8, 2013 Share Posted April 8, 2013 I appreciate the creation of this thread and would like to see more like it to track each individual severe threat. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted April 8, 2013 Author Share Posted April 8, 2013 I appreciate the creation of this thread and would like to see more like it to track each individual severe threat. That or get the 1 thread to update the title to be more specific with timing each time. Link to comment Share on other sites More sharing options...
nrgjeff Posted April 8, 2013 Share Posted April 8, 2013 Fortunately for the public still perhaps in a winter lull, I don't think this week will be too bad in Dixie Alley. First off, Central/West forum has a good handle on the Plains. Today is conditional in NW Kansas. In three weeks, that’d be a gem of a setup. Tuesday will feature a squall line undercut by cold air – SPC notes that as well. Wednesday will feature unidirectional winds. I can hardly imagine even a lot of straight line winds Tue/Wed. In addition the whole thing is positively tilted until crossing the Mississippi River. Thursday is the day thunderstorms reach Dixie Alley. Both GFS and Euro have the positively tilted system going to a more negative tilt. However it closes off up in the Ohio Valley, netting little gain for storm chasing interests. Rather than an open negative wave, it’s a closed upper system lumbering up into the Ohio Valley. Best upper dynamics likely to be well north of Dixie thermodynamics. There is a southern jet stream progged to eject out of Texas. However it just curves north and though not quite unidirectional, directional wind shear with height is lackluster. All of the above is why SPC rightly punts on a Day 4 forecast. However I’ll commit. How about a lovely warm week and no severe – just heavy rain. Our friends in Dixie alley perhaps can safely have their cake and eat it too! Link to comment Share on other sites More sharing options...
WNCwx Posted April 8, 2013 Share Posted April 8, 2013 I just hate it that the line (whether it develops a QLCS or not) will be crossing western North Carolina in the dark when there will be no photo ops. At least I'll have the public safety traffic to report on my Twitter and Fakebook™ pages. *edited for grammar.* Link to comment Share on other sites More sharing options...
DixieBlizzard Posted April 8, 2013 Share Posted April 8, 2013 This is not a significant threat. You are the queen of hyperbole Wilkesborogal. Link to comment Share on other sites More sharing options...
LithiaWx Posted April 8, 2013 Share Posted April 8, 2013 I appreciate the creation of this thread and would like to see more like it to track each individual severe threat. Link to comment Share on other sites More sharing options...
oconeexman Posted April 8, 2013 Share Posted April 8, 2013 This is not a significant threat. You are the queen of hyperbole Wilkesborogal. Bahaha good one! Link to comment Share on other sites More sharing options...
DixieBlizzard Posted April 8, 2013 Share Posted April 8, 2013 Bahaha good one! Most people in North GA just love ol' Wilkes. He became near and dear to us over the winter. (he IS a drama queen though)... Link to comment Share on other sites More sharing options...
WilkesboroDude Posted April 9, 2013 Author Share Posted April 9, 2013 It appears a Slight Risk will cover many of us tomorrow on the day 3 outlook. Link to comment Share on other sites More sharing options...
Poimen Posted April 9, 2013 Share Posted April 9, 2013 Link to comment Share on other sites More sharing options...
Jon Posted April 9, 2013 Share Posted April 9, 2013 It appears a Slight Risk will cover many of us tomorrow on the day 3 outlook. many of us? what are you looking at??? Link to comment Share on other sites More sharing options...
WilkesboroDude Posted April 9, 2013 Author Share Posted April 9, 2013 many of us? what are you looking at??? SPC Link to comment Share on other sites More sharing options...
WilkesboroDude Posted April 9, 2013 Author Share Posted April 9, 2013 Special Statement Statement as of 3:47 PM CDT on April 08, 2013 ... Severe storms possible late Wednesday night and Thursday... A strong cold front is expected to move across middle Tennessee late Wednesday night or Thursday... with a line of showers and thunderstorms developing along the front and pushing across the mid state. Conditions appear favorable for some of the thunderstorms late Wednesday night or Thursday to be strong to severe. However... major differences between computer model guidance lead to considerable uncertainty on the timing and degree of any severe weather that could impact the mid state. April is the peak month for severe weather across middle Tennessee. Prepare ahead for potential severe weather by monitoring the latest forecasts and checking batteries in your NOAA Weather Radio. Stay tuned to local media and weather.Gov for the latest information on this potential severe weather situation. Link to comment Share on other sites More sharing options...
MADDOGG Posted April 9, 2013 Share Posted April 9, 2013 Wilkes you must be doing somthing right (the way your stir up ol farts is amazing) Link to comment Share on other sites More sharing options...
nrgjeff Posted April 9, 2013 Share Posted April 9, 2013 When the thread was created, it was justified. However the whole event has fallen apart like Kansas in the last 40 seconds vs Michigan, or UNC in the 2nd half vs Kansas. Plenty of pain to go around. Oh yeah, weather.... Looks like a squall line Wed/Thur. Winds nearly unidirectional surface to jet stream. Cold front rushing east killing any chance of a dry line. NAM/WRF shows pre-frontal trough intermittently on a few panels, but not consistently, and I doubt it happens at all. Surface cool pool outruns upper dynamics. Complete melt-down if you believe models days out. Otherwise, law of averages generally favors fading events until 1-2 days out. No surprises here. Enjoy the warm temperatures before the front! Link to comment Share on other sites More sharing options...
MADDOGG Posted April 9, 2013 Share Posted April 9, 2013 LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...THE GFS REMAINS SLIGHTLY FASTER THAN THE ECMWF WITH REGARDS TOTIMING OF NEXT FRONTAL PASSAGE... WITH GFS PUSHING THE COLD FRONTINTO NW GA EARLY THURSDAY EVENING... AND ECMWF NOT UNTIL MIDNIGHTOR LATER FOR THIS SAME LOCATION. DESPITE MODEL DIFFERENCES...CONFIDENCE IS INCREASING THAT AT LEAST ISOLATED SEVERE STORMS WILLACCOMPANY THIS STORM SYSTEM. ALTHOUGH MODEL INSTABILITIES APPEARMODEST... WITH MAYBE 400-800 MLCAPE SPREADING INTO NORTH GA THURSDAYAFTERNOON AND EVENING... BOTH MODELS SHOW A STRONG UPPER DISTURBANCESTRENGTHENING WIND PROFILES... WHICH WOULD SERVE TO ENHANCEEXPECTED SQUALL LINE CONVECTION PUSHING ACROSS ALABAMA AND INTO NWAND WEST CENTRAL GA LATE THURSDAY AFTERNOON OR EARLY EVENINGAHEAD OF THE APPROACHING COLD FRONT. AT THIS TIME... IT APPEARSTHE MAIN THREAT WOULD BE DAMAGING WINDS FROM BOWING ECHOES EMBEDDEDWITHIN THE EXPECTED SQUALL LINE. HOWEVER... A LOW CAPE...HIGH WINDSHEAR ENVIRONMENT WOULD SUPPORT A FEW TORNADOES... ESPECIALLY IFANY ISOLATED SUPER CELL STORMS CAN DEVELOP OUT AHEAD OF THE SQUALLLINE. ALTHOUGH STRONG TO SEVERE STORMS WILL BE POSSIBLE ACROSS ALLOF NORTH AND CENTRAL GA PER LATEST DAY 3 OUTLOOK FROM SPC...TIMING OF UPPER SUPPORT WOULD SUGGEST THE GREATEST SEVERE THREATWOULD BE GENERALLY ALONG AND WEST OF AN AMERICUS TO COVINGTON TOBLAIRSVILLE LINE... AND MAINLY FROM LATE THURSDAY AFTERNOON THROUGHMAYBE 4 AM FRIDAY MORNING. HOWEVER... THIS COULD CHANGE... AND ALLINTEREST ACROSS NORTH AND CENTRAL GA ARE ADVISED TO CLOSELY MONITORLATER FORECAST CONCERNING THIS NEXT POTENTIALLY DANGEROUS WEATHERSYSTEM. THE HEAVIEST RAINFALL AMOUNTS STILL APPEAR TO BE ACROSSNORTH AND WEST CENTRAL GA WHERE 1 TO 2 INCHES ARE EXPECTED... WITHGENERALLY AN INCH OR LESS LIKELY ELSEWHERE. OTHERWISE... EXPECTCLEARING CONDITIONS ON FRIDAY BEHIND THE DEPARTING COLD FRONT WITHHIGH PRESSURE IN CONTROL THROUGH AT LEAST EARLY SUNDAY. AS THESURFACE RIDGE SLIPS EAST... A MOIST SOUTHERLY WIND FLOW COULD BEENHANCED BY AN ACTIVE WESTERLY FLOW ALOFT TO BRING ISOLATED SHOWERSBACK INTO THE FORECAST FOR LATE SUNDAY INTO MONDAY. HAVE KEPT COVERAGEISOLATED WITH NO MENTION OF THUNDER FOR NOW. 39 Link to comment Share on other sites More sharing options...
Jon Posted April 9, 2013 Share Posted April 9, 2013 When the thread was created, it was justified. However the whole event has fallen apart like Kansas in the last 40 seconds vs Michigan, or UNC in the 2nd half vs Kansas. Plenty of pain to go around. Oh yeah, weather.... Looks like a squall line Wed/Thur. Winds nearly unidirectional surface to jet stream. Cold front rushing east killing any chance of a dry line. NAM/WRF shows pre-frontal trough intermittently on a few panels, but not consistently, and I doubt it happens at all. Surface cool pool outruns upper dynamics. Complete melt-down if you believe models days out. Otherwise, law of averages generally favors fading events until 1-2 days out. No surprises here. Enjoy the warm temperatures before the front! The tor threat in Oklahoma is weaksauce right now...especially with a moderate risk and it being April 9th... Link to comment Share on other sites More sharing options...
WilkesboroDude Posted April 9, 2013 Author Share Posted April 9, 2013 I like squall lines. It provides a greater and widespread chance of thunderstorms instead of the spotty discrete supercells that never affect me. Link to comment Share on other sites More sharing options...
WNCwx Posted April 10, 2013 Share Posted April 10, 2013 Well, for the few of us who care about the westernmost reaches of the Southeast, here is the Day 2 Outlook Categorical: The text from the GSP Disco: .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...AS OF 245 AM WED...A DEEP LOW PRES SYSTEM WILL EMERGE FROM THEPLAINS THU MORNING AND MOVE TOWARD THE GREAT LAKES. SHORTWAVE ENERGYEJECTING FROM THE BASE OF THE ASSOCIATED TROUGH OVER THE LOWER MSVALLEY WILL DRIVE A STRONG COLD FRONT ACROSS THE MID AND DEEP SOUTHTOWARD THE REGION. IN THE INCREASINGLY HUMID WARM SECTOR AIRMASSAHEAD OF THE APPROACHING FRONT...SCATTERED CONVECTION SHOULD DEVELOPBY MIDDAY THU AS THE CAPPING INVERSION WEAKENS...WITH COVERAGESTEADILY GROWING ACROSS THE WRN AND SRN PARTS OF THE FORECAST AREATHROUGH THU AFTN. STRONGER DISCRETE CONVECTION IS MOST LIKELY INAREAS SE OF INTERSTATE 85 LATE THU AFTERNOON WHERE THE LOW TO MID60S DEWPOINT POOL WILL LIKELY BE IN PLACE. 850 MB FLOW SHOULDSTRENGTHEN AND BACK SLIGHTLY THROUGH THU EVENING AS THE UPPERSHORTWAVE AND FRONT APPROACH...AND UPPER JET DIVERGENCE WILLINCREASE THROUGH THE EVENING HOURS TO IMPROVE FORCING AS WELL. THESPC 3 HR CALIBRATED SEVERE THUNDERSTORM SREF GUIDANCE INDICATES THEGREATEST SVR TSTM CHANCES IN NE GA AND THE WRN UPSTATE AROUND 00ZFRI...WITH CHANCES DIMINISHING SLIGHTLY FARTHER EAST OVERNIGHT.HOWEVER...A QLCS THREAT SHOULD CONTINUE ACROSS THE ERN PIEDMONTTHROUGH THE OVERNIGHT HOURS...ESPECIALLY IF THE SHARPER ECMWFSHORTWAVE VERIFIES 06Z TO 12Z FRI. THE COMBINATION OF THESE FEATURESWARRANTS THE SLIGHT RISK OF SEVERE TSTMS CURRENTLY FEATURED ACROSSTHE REGION IN THE SPC DAY 2 OUTLOOK...AND THE SEVERE THREAT WILLCONTINUE TO BE ADVERTISED IN THE HWO.THE COLD FRONT AND ATTENDANT DEEP MOISTURE SHOULD CROSS THE AREAFAST ENOUGH PM THU THROUGH AM FRI TO LIMIT HYDRO CONCERNS.HOWEVER...LOCALLY HEAVY RAINFALL CAN CERTAINLY BE EXPECTED WITH ANYTRAINING CONVECTION AND IN SRLY UPSLOPE AREAS OF THE SRN MTNS.GRADIENT WINDS COULD ALSO POSE A PROBLEM AT THE HIGHER ELEVATIONSTHU EVENING...BUT WITH ANY 40+ MPH GUSTS LIMITED MAINLY TOELEVATIONS ABOVE 3500 FEET. A DRYING AND DOWNSLOPING FLOW ISEXPECTED POST FROPA ON FRI...WITH ANY WESTERLY UPSLOPE MOISTURE INTHE WRN MTNS BEING TOO SHALLOW FOR ANY LINGERING SHOWERS ALONG THESPINE FRI/FRI NIGHT. It is too bad that these things mostly cross my section of southwestern North Carolina after dark. Perhaps there will be renewed interest in this system from certain cliques since they do mention possible QLCS for the Piedmont. As for us in the mountains, it's gonna be an interesting night listening to the scanner as firefighters will have to do battle with falling trees as this storm passes through. Link to comment Share on other sites More sharing options...
NavarreDon Posted April 10, 2013 Share Posted April 10, 2013 GSP's overnight: .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...AS OF 245 AM WED...A DEEP LOW PRES SYSTEM WILL EMERGE FROM THEPLAINS THU MORNING AND MOVE TOWARD THE GREAT LAKES. SHORTWAVE ENERGYEJECTING FROM THE BASE OF THE ASSOCIATED TROUGH OVER THE LOWER MSVALLEY WILL DRIVE A STRONG COLD FRONT ACROSS THE MID AND DEEP SOUTHTOWARD THE REGION. IN THE INCREASINGLY HUMID WARM SECTOR AIRMASSAHEAD OF THE APPROACHING FRONT...SCATTERED CONVECTION SHOULD DEVELOPBY MIDDAY THU AS THE CAPPING INVERSION WEAKENS...WITH COVERAGESTEADILY GROWING ACROSS THE WRN AND SRN PARTS OF THE FORECAST AREATHROUGH THU AFTN. STRONGER DISCRETE CONVECTION IS MOST LIKELY INAREAS SE OF INTERSTATE 85 LATE THU AFTERNOON WHERE THE LOW TO MID60S DEWPOINT POOL WILL LIKELY BE IN PLACE. 850 MB FLOW SHOULDSTRENGTHEN AND BACK SLIGHTLY THROUGH THU EVENING AS THE UPPERSHORTWAVE AND FRONT APPROACH...AND UPPER JET DIVERGENCE WILLINCREASE THROUGH THE EVENING HOURS TO IMPROVE FORCING AS WELL. THESPC 3 HR CALIBRATED SEVERE THUNDERSTORM SREF GUIDANCE INDICATES THEGREATEST SVR TSTM CHANCES IN NE GA AND THE WRN UPSTATE AROUND 00ZFRI...WITH CHANCES DIMINISHING SLIGHTLY FARTHER EAST OVERNIGHT.HOWEVER...A QLCS THREAT SHOULD CONTINUE ACROSS THE ERN PIEDMONTTHROUGH THE OVERNIGHT HOURS...ESPECIALLY IF THE SHARPER ECMWFSHORTWAVE VERIFIES 06Z TO 12Z FRI. THE COMBINATION OF THESE FEATURESWARRANTS THE SLIGHT RISK OF SEVERE TSTMS CURRENTLY FEATURED ACROSSTHE REGION IN THE SPC DAY 2 OUTLOOK...AND THE SEVERE THREAT WILLCONTINUE TO BE ADVERTISED IN THE HWO.THE COLD FRONT AND ATTENDANT DEEP MOISTURE SHOULD CROSS THE AREAFAST ENOUGH PM THU THROUGH AM FRI TO LIMIT HYDRO CONCERNS.HOWEVER...LOCALLY HEAVY RAINFALL CAN CERTAINLY BE EXPECTED WITH ANYTRAINING CONVECTION AND IN SRLY UPSLOPE AREAS OF THE SRN MTNS.GRADIENT WINDS COULD ALSO POSE A PROBLEM AT THE HIGHER ELEVATIONSTHU EVENING...BUT WITH ANY 40+ MPH GUSTS LIMITED MAINLY TOELEVATIONS ABOVE 3500 FEET. A DRYING AND DOWNSLOPING FLOW ISEXPECTED POST FROPA ON FRI...WITH ANY WESTERLY UPSLOPE MOISTURE INTHE WRN MTNS BEING TOO SHALLOW FOR ANY LINGERING SHOWERS ALONG THESPINE FRI/FRI NIGHT. Link to comment Share on other sites More sharing options...
MADDOGG Posted April 10, 2013 Share Posted April 10, 2013 Sounds like they might arrive to late for my area, that being said i have high confidence that whatever is left will be killed by the GA/AL line! I will say those storms we had back a few weeks ago when the temp was in the 40's where very strong being the temp it was. Link to comment Share on other sites More sharing options...
andyhb Posted April 10, 2013 Share Posted April 10, 2013 45% probs added for tomorrow. DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 PM CDT WED APR 10 2013 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS THU AND THU NIGHT ACROSS THE LOWER OHIO/TENNESSEE VALLEYS AND CENTRAL/EASTERN GULF STATES INTO THE CAROLINAS... ...SYNOPSIS... TO THE SOUTH OF A PROMINENT HIGHER LATITUDE BLOCK...MODELS SUGGEST THAT UPPER TROUGHING ENCOMPASSING MUCH OF THE INTERIOR OF THE U.S. WILL PERSIST...BUT CYCLONIC FLOW MAY BEGIN TO BECOME LESS AMPLIFIED DURING THIS FORECAST PERIOD. ONLY A SLOW EASTWARD PROGRESSION OF A MID-LEVEL CLOSED LOW FROM THE MID MISSOURI VALLEY INTO THE UPPER MIDWEST IS FORECAST THURSDAY AND THURSDAY NIGHT. BUT...A SIGNIFICANT SHORT WAVE IMPULSE...NOW DIGGING INTO THE BASE OF LARGER SCALE TROUGHING ACROSS THE NORTHERN MEXICAN PLATEAU...APPEARS LIKELY TO ACCELERATE EAST NORTHEAST OF THE LOWER RIO GRANDE VALLEY THROUGH THE CENTRAL/SOUTHERN APPALACHIANS/MID ATLANTIC REGION BY 12Z FRIDAY. UNCERTAINTY LINGERS CONCERNING TIMING...BUT THE MOST RAPID ACCELERATION MAY OCCUR EAST OF THE LOWER MISSISSIPPI VALLEY THURSDAY EVENING INTO THE OVERNIGHT HOURS. AS THIS OCCURS...INCREASED COUPLING OF AN ASSOCIATED 500 MB JET STREAK WITH A STRENGTHENING 850 MB SPEED MAXIMUM APPEARS PROBABLE ACROSS THE EASTERN GULF STATES INTO THE CAROLINAS...ACCOMPANIED BY SECONDARY FRONTAL WAVE DEVELOPMENT ACROSS SOUTHEASTERN MISSISSIPPI AND CENTRAL ALABAMA INTO THE LEE OF THE SOUTHERN APPALACHIANS. MODELS ALSO SUGGEST THAT THERE WILL BE CONTINUED SLOW DEEPENING OF THE PRIMARY SURFACE CYCLONE ACROSS SOUTHERN PORTIONS OF THE GREAT LAKES REGION...WEST OF THE APPALACHIANS. THE TRAILING COLD FRONT IS EXPECTED TO ADVANCE EAST OF THE MISSISSIPPI VALLEY...INTO THE VICINITY OF THE APPALACHIANS BY THE END OF THE PERIOD...AS A SIGNIFICANT PRECEDING INTRUSION OF COLD AIR IS SLOW TO MODIFY ACROSS THE LOWER GREAT LAKES REGION AND MUCH OF THE NORTHEAST. ...LWR OH/TN VALLEYS AND CNTRL/ERN GULF STATES INTO CAROLINAS... DEEP LAYER SHEAR IS EXPECTED TO BECOME MORE THAN SUFFICIENT FOR SEVERE STORMS WITHIN THE WARM ENVIRONMENT ENCOMPASSING A LARGE PORTION OF THE EASTERN U.S...AHEAD OF THE FRONT ADVANCING EAST OF THE MISSISSIPPI VALLEY...AND SOUTH OF THE STALLING FRONT ACROSS THE UPPER OHIO VALLEY AND MID ATLANTIC COAST REGION. AND SOME ASPECTS OF THE EVOLVING LARGE SCALE PATTERN APPEAR FAVORABLE FOR A MORE SIGNIFICANT SEVERE WEATHER OUTBREAK THAN INDICATED BY THE CURRENT CATEGORICAL AND PROBABILISTIC OUTLOOKS. HOWEVER...ONE PROMINENT POTENTIAL LIMITING FACTOR EVIDENT IN MODEL FORECASTS IS THE CONTINUING PRESENCE OF DRIER POCKETS WITHIN THE WARM SECTOR INTO THE DAY THURSDAY...PARTICULARLY IN THE BOUNDARY LAYER...EAST OF THE CENTRAL APPALACHIANS...AND ACROSS THE CUMBERLAND PLATEAU SOUTHWARD INTO EASTERN GULF COASTAL AREAS. WHILE THIS MAY MODIFY SOME ON SOUTHERLY LOW-LEVEL FLOW...RICHER BOUNDARY LAYER MOISTURE CHARACTERIZED BY UPPER 60S/70S DEW POINTS IS NOT EXPECTED INLAND OF IMMEDIATE GULF COASTAL AREAS DURING THIS PERIOD. EARLY PERIOD PRE-FRONTAL CONVECTION AND ASSOCIATED CLOUD COVER PROVIDE ADDITIONAL UNCERTAINTY CONCERNING DESTABILIZATION... PARTICULARLY ACROSS THE LOWER OHIO/TENNESSEE VALLEYS. HOWEVER... AT LEAST A NARROW NORTH/SOUTH CORRIDOR OF WEAK TO MODERATE BOUNDARY LAYER BASED DESTABILIZATION APPEARS PROBABLE DURING THE PEAK AFTERNOON HEATING. IN THE PRESENCE OF WIND PROFILES...WHICH FORECAST SOUNDINGS SUGGESTS COULD EXHIBIT PRONOUNCED LOW-LEVEL HODOGRAPH SIZE AND CLOCKWISE CURVATURE...STRONG/SEVERE STORMS APPEAR PROBABLE...INCLUDING THE RISK FOR AT LEAST A FEW DISCRETE SUPERCELLS CAPABLE OF PRODUCING TORNADOES AND LARGE HAIL. FARTHER SOUTH...PROBABILITIES FOR THE EVOLUTION OF AN ORGANIZED SEVERE MESOSCALE CONVECTIVE SYSTEM APPEAR HIGHER AS FORCING/SHEAR INCREASES IN ASSOCIATION WITH THE ACCELERATING SHORT WAVE IMPULSE ...ACROSS ALABAMA/GEORGIA BY EARLY THURSDAY EVENING. THIS MAY BE ACCOMPANIED BY A MORE SUBSTANTIVE/WIDESPREAD DAMAGING WIND THREAT. TORNADOES AND LARGE HAIL WILL ALSO BE POSSIBLE WITH THIS ACTIVITY. ..KERR.. 04/10/2013 Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.