Srain Posted March 8, 2011 Share Posted March 8, 2011 MESOSCALE DISCUSSION 0204 NWS STORM PREDICTION CENTER NORMAN OK 0952 AM CST TUE MAR 08 2011 AREAS AFFECTED...MUCH OF LA AND SRN MS CONCERNING...OUTLOOK UPGRADE VALID 081552Z - 081645Z MUCH OF LA INTO SRN MS IS BEING UPGRADED TO A MODERATE RISK IN THE UPCOMING 1630Z DAY 1 CONVECTIVE OUTLOOK. CONDITIONS ARE EXPECTED TO BECOME FAVORABLE LATER THIS AFTERNOON THROUGH TONIGHT FOR A FEW STRONG AND POSSIBLY LONG-LIVED TORNADOES ACROSS THIS REGION. FURTHER DETAILS WILL BE AVAILABLE IN THE MORNING UPDATE OF THE DAY 1 OUTLOOK. ..PETERS.. 03/08/2011 ATTN...WFO...MOB...JAN...LIX...LCH...SHV... Link to comment Share on other sites More sharing options...
kwt Posted March 8, 2011 Share Posted March 8, 2011 Well there is that moderate risk I think we were all waiting for. Just waiting now till the later afternoon hours and eveing hours to get things sparking up. Is anyone here chasing, I know the area is pretty pants but there is always one that will chance it? Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 8, 2011 Share Posted March 8, 2011 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1025 AM CST TUE MAR 08 2011 VALID 081630Z - 091200Z ...THERE IS A MDT RISK OF SVR TSTMS PARTS OF LA AND SRN MS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF EAST TX/OK INTO THE LOWER MS VALLEY... ...SYNOPSIS... LARGE SCALE TROUGH SHIFTS EWD ACROSS PLAINS THRU THE FORECAST PERIOD. ONE S/WV NOW ROTATING NEWD THRU KS/NRN OK WHILE UPSTREAM VORT MAX CENTRAL NM MOVES EWD ACROSS SRN PLAINS TO LOWER MS VALLEY 12Z WED. IMPRESSIVE MOISTURE STREAMING NWD FROM WRN GULF INTO SRN PLAINS AND LOWER MS VALLEY THRU THIS EVENING AS A WARM FRONT DEVELOPS INLAND ACROSS SERN TX EWD INTO SRN MS BY LATER THIS AFTERNOON. STEEP MID LEVEL LAPSE RATES HAVE SPREAD EWD ACROSS SRN PLAINS INTO LOWER MS VALLEY THIS MORNING ATOP THE DEEPENING LOW LEVEL MOISTURE AS DEWPOINTS RISE THRU THE 60S BY THIS AFTERNOON ACROSS LWR MS VALLEY. ..LA/MS LATER THIS AFTERNOON AND TONIGHT... THE FOCUSING MECHANISMS FOR CONVECTIVE DEVELOPMENT REMAIN A QUESTION ATTM HOWEVER A WEAK CAPPING INVERSION AND INCREASING LARGE SCALE FORCING ARE EXPECTED TO RESULT IN SCATTERED DISCRETE THUNDERSTORM DEVELOPMENT IN A RATHER STRONGLY SHEARED ENVIRONMENT. FORECAST SOUNDINGS SUGGEST EFFECTIVE SHEAR VALUES OF 40-50 KNOTS AND 0-3KM SRH OF 250-350 M2/S2. WITH LARGE SCALE ASCENT INCREASING BOTH DUE TO CONTINUED WARM ADVECTION AND APPROACH OF THE NM IMPULSE AND MID/UPPER LEVEL WIND MAX... DISCRETE THUNDERSTORM DEVELOPMENT APPEARS LIKELY BY LATER THIS AFTERNOON AND EVENING VICINITY OF THE WARM FRONT MOVING INLAND ACROSS LA AND SRN MS. GIVEN THAT MLCAPES INCREASE TO 1500 J/KG AND FAVORABLE SHEAR ENVIRONMENT NOW IN PLACE WILL JUST IMPROVE THRU THE AFTERNOON...THE THREAT OF SUPERCELLS DEVELOPING INCLUDING TORNADOES ARE LIKELY BEGINNING BY LATE THIS AFTERNOON AND CONTINUING TONIGHT ACROSS LA INTO SRN MS. THERE IS THE RISK OF STRONG TORNADOES. UPSCALE ORGANIZATION INTO BOWS/LEWPS IS POSSIBLE OVERNIGHT WITH THE POTENTIAL FOR DAMAGING WINDS SPREADING EWD INTO WRN AL. PORTION OF THIS AREA HAS BEEN UPGRADED TO A MDT RISK DUE TO THE GREATER CONFIDENCE OF THE POTENTIAL FOR STRONG TORNADOES. ...OK/TX/AR/LA... BY LATER THIS AFTERNOON...THE SURFACE DRYLINE WILL SURGE EASTWARD INTO EAST-CENTRAL OK AND CENTRAL TX. MODELS STILL DIFFER ON THE EXTENT OF CONVECTIVE DEVELOPMENT ALONG THE BOUNDARY...BUT SUFFICIENT RISK IS PRESENT TO MAINTAIN SLIGHT RISK ALONG THIS CORRIDOR. THOSE STORMS THAT DO DEVELOP WILL POSE A THREAT OF LARGE HAIL... DAMAGING WINDS...AND EVEN ISOLATED TORNADOES. IT APPEARS THE MOST LIKELY AREA FOR THUNDERSTORMS ALONG THE DRYLINE WILL BE ALONG AND IMMEDIATELY SOUTH OF THE RED RIVER LATER TODAY. THESE STORMS WILL SPREAD EASTWARD INTO PORTIONS OF AR/LA THIS EVENING WITH A CONTINUED SEVERE THREAT. ..HALES/GRAMS.. 03/08/2011 Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 8, 2011 Share Posted March 8, 2011 Link to comment Share on other sites More sharing options...
blackjack123 Posted March 8, 2011 Share Posted March 8, 2011 So is this potential tornado outbreak going to happen later on this evening/tonight? Is it possible it might be earlier? Link to comment Share on other sites More sharing options...
CUmet Posted March 8, 2011 Share Posted March 8, 2011 I'm probably on the cautious end about this event. Although the moisture and low-level shear are certainly impressive during the evening/overnight hours, especially near the retreating warm front, there are several big question marks about this event. 1) Narrow warm sector, because of poor low-level trajectories in the past few days advected modified continental air. Mind you, areas in East TX, LA, and southern MS will see mid-upper 60s dewpoints easily, but the warm sector has a distinct inverted-V shape that is usually associated with underachieving events in my experience. This reduces the areal coverage of the significant events down to LA and SW MS, and reduces the amount of room for error. The latest RUC and HRRR runs already show a slower northward push of the warm front than the NAM/GFS indicate. 2) Relatively unimpressive wind fields, particularly in the mid-upper levels. The trough is passing by well to the north, and is negatively-tilted. The 0-6 km shear in the aforementioned threat areas look to be on the order of 50 kt, which isn't absolutely terrible, but not too impressive for low-moderate instability cases like this one. 3) Warm mid-levels. It may be difficult to get deep convection to initiate in the free warm sector, certainly before 00z. A bigger problem is that the forecast soundings indicate little CAPE in the lowest 3 km, with lapse rates nearly moist-adiabatic up to 650 mb or so. Now, I don't want to completely downplay this event, as it only takes one or two significant tornadoes (especially at night) to do a lot of damage. However, these are my honest thoughts regarding tonight. Link to comment Share on other sites More sharing options...
wxsmwhrms Posted March 8, 2011 Share Posted March 8, 2011 I'm probably on the cautious end about this event. Although the moisture and low-level shear are certainly impressive during the evening/overnight hours, especially near the retreating warm front, there are several big question marks about this event. 1) Narrow warm sector, because of poor low-level trajectories in the past few days advected modified continental air. Mind you, areas in East TX, LA, and southern MS will see mid-upper 60s dewpoints easily, but the warm sector has a distinct inverted-V shape that is usually associated with underachieving events in my experience. This reduces the areal coverage of the significant events down to LA and SW MS, and reduces the amount of room for error. The latest RUC and HRRR runs already show a slower northward push of the warm front than the NAM/GFS indicate. 2) Relatively unimpressive wind fields, particularly in the mid-upper levels. The trough is passing by well to the north, and is negatively-tilted. The 0-6 km shear in the aforementioned threat areas look to be on the order of 50 kt, which isn't absolutely terrible, but not too impressive for low-moderate instability cases like this one. 3) Warm mid-levels. It may be difficult to get deep convection to initiate in the free warm sector, certainly before 00z. A bigger problem is that the forecast soundings indicate little CAPE in the lowest 3 km, with lapse rates nearly moist-adiabatic up to 650 mb or so. Now, I don't want to completely downplay this event, as it only takes one or two significant tornadoes (especially at night) to do a lot of damage. However, these are my honest thoughts regarding tonight. I pretty much agree with this, except for point three. While there is a bit of a warm nose around maybe 600-700 mb, the mid/upper levels are actually quite cold for this time of year around -15C at 500 mb and -40C at 300 mb. I don't think there's going to be any problem getting convection going in the warm sector tonight as some moderate height falls moving into the area. That actually I guess gives me some disagreement with point 2 - the models are showing MLCAPE values around 1000 J/kg, which is plenty sufficient for intense supercells with 50 kt of 0-6km shear. There is a pretty favorable looking setup for high end tors but it's a pretty small area, namely SW MS into central and maybe SE LA. Overall I think SPC has a very good handle on things. Link to comment Share on other sites More sharing options...
CUmet Posted March 8, 2011 Share Posted March 8, 2011 I pretty much agree with this, except for point three. While there is a bit of a warm nose around maybe 600-700 mb, the mid/upper levels are actually quite cold for this time of year around -15C at 500 mb and -40C at 300 mb. I don't think there's going to be any problem getting convection going in the warm sector tonight as some moderate height falls moving into the area. That actually I guess gives me some disagreement with point 2 - the models are showing MLCAPE values around 1000 J/kg, which is plenty sufficient for intense supercells with 50 kt of 0-6km shear. There is a pretty favorable looking setup for high end tors but it's a pretty small area, namely SW MS into central and maybe SE LA. Overall I think SPC has a very good handle on things. I guess it's depends whether one is glass half-empty or half-full (I tend to be of the former). The deep-layer shear is sufficient, yes, but it's just not that impressive to me given the relatively low CAPE. If we were talking about May and had CAPE of over 2000 J/kg, that would impress me. The lapse rates above 700 mb are certainly impressive, but the low-levels are relatively lacking. Everything below 700 is nearly moist-adiabatic, and you usually get the grungy mess with that kind of air mass. Probably the biggest thing, though, is the fact that the favorable parameters overlap over such a small area...meaning that everything has to go absolutely perfect, and there's that much more opportunity for "failure". I'm probably slightly more conservative than SPC, but I agree that they're handling things well. Link to comment Share on other sites More sharing options...
wxsmwhrms Posted March 8, 2011 Share Posted March 8, 2011 I guess it's depends whether one is glass half-empty or half-full (I tend to be of the former). The deep-layer shear is sufficient, yes, but it's just not that impressive to me given the relatively low CAPE. If we were talking about May and had CAPE of over 2000 J/kg, that would impress me. The lapse rates above 700 mb are certainly impressive, but the low-levels are relatively lacking. Everything below 700 is nearly moist-adiabatic, and you usually get the grungy mess with that kind of air mass. Probably the biggest thing, though, is the fact that the favorable parameters overlap over such a small area...meaning that everything has to go absolutely perfect, and there's that much more opportunity for "failure". I'm probably slightly more conservative than SPC, but I agree that they're handling things well. No disagreement with this at all. If anyone is expecting classic supercells, they will be disappointed. Going to be lots of HP looking structures, bows, loops, etc. Significant heavy rain risk as well. Link to comment Share on other sites More sharing options...
David Reimer Posted March 8, 2011 Share Posted March 8, 2011 I just left Dallas and am heading towards the Greenville area. Live streaming video and GPS data available at www.texasstormchasers.com/live Link to comment Share on other sites More sharing options...
Ed Lizard Posted March 8, 2011 Share Posted March 8, 2011 Forgive me for some IMBYism, but I think well West of main risk area, clouds are thinning noticeably near the I-35 corridor ahead of the diffuse dryline. Not super IMBY, RUC has mother off all caps overhead HOU area. Link to comment Share on other sites More sharing options...
Srain Posted March 8, 2011 Share Posted March 8, 2011 MESOSCALE DISCUSSION 0205 NWS STORM PREDICTION CENTER NORMAN OK 1254 PM CST TUE MAR 08 2011 AREAS AFFECTED...LA...SRN AR...AND PARTS OF CENTRAL/SWRN MS CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY VALID 081854Z - 081930Z TORNADO WATCH WILL BE COORDINATED SOON FOR PARTS OF SRN LA INTO SWRN MS...GIVEN SUBSTANTIAL WEAKENING OF THE CAP PER THE SPECIAL 18Z LCH SOUNDING AND STRONG LOW LEVEL AND DEEP LAYER SHEAR WITHIN DESTABILIZING AIR MASS. A SEVERE TSTM WATCH IS POSSIBLE FARTHER N ACROSS PARTS OF NRN LA/SRN AR INTO CENTRAL MS FOR PRIMARILY A HAIL THREAT THIS AFTERNOON. TSTM COVERAGE SHOULD GRADUALLY INCREASE ACROSS NRN LA/SRN AR INTO CENTRAL AND SWRN MS THIS AFTERNOON...WHILE ADDITIONAL STORMS DEVELOP OVER SRN LA. INITIAL THREAT WILL BE HAIL GIVEN ELEVATED TSTMS WITH MUCH OF THIS EARLY-MID AFTERNOON ACTIVITY. HOWEVER... STORMS DEVELOPING OVER SRN LA ARE LOCATED INVOF THE NWD MOVING WARM FRONT...AND ARE LIKELY SURFACE BASED OR NEARLY SO. LATE MORNING/EARLY AFTERNOON SURFACE ANALYSES SHOWED THE WARM FRONT HAD MOVED A LITTLE FARTHER INLAND ACROSS THE SRN EXTENT OF LA AND EXTENDED NWWD THROUGH E TX TO AN AREA OF LOW PRESSURE OVER NORTH CENTRAL TX. SURFACE DEWPOINT TEMPERATURES IN THE UPPER 60S WERE LOCATED AS FAR INLAND AS LCH-LFT AND WWD INTO SE TX...WHILE MID 60S VALUES EXTENDED FROM POE TO BTR. REGIONAL RADAR IMAGERY SHOWED TSTMS LOCATED E/SE OF LFT AND W OF BTR...WITH THIS ACTIVITY DEVELOPING ALONG THE ERN EXTENT OF GREATER CLOUD COVER WHERE SURFACE HEATING IS STRONGER...AIDING IN BOOSTING INSTABILITY /MUCAPE 1000-1500 J PER KG/. THERMODYNAMICS AND INCREASING EFFECTIVE BULK SHEAR /40-50 KT/ WILL SUPPORT ORGANIZED STORMS WITH THREATS FOR HAIL AND DAMAGING WINDS. ANY STORM FORMING NEAR THE WARM FRONT WILL HAVE A GREATER POTENTIAL TO PRODUCE A TORNADO...GIVEN LOW LEVEL HODOGRAPH CURVATURE PER 18Z LCH VAD. FARTHER N...STORMS DEVELOPING OVER NRN LA AND ACROSS AR INTO SWRN TO CENTRAL MS WILL LIKELY REMAIN ELEVATED THROUGH THE AFTERNOON GIVEN DISTANCE FROM WARM SECTOR. FAVORABLE THERMODYNAMICS /STEEP MIDLEVEL LAPSE RATES ATOP RETURNING LOW LEVEL MOISTURE/ AND INCREASING EFFECTIVE BULK SHEAR AS STRONGER MIDLEVEL WINDS SPREAD EWD WITH APPROACHING SRN PLAINS TROUGH WILL SUPPORT STORM ORGANIZATION. HAIL WILL BE THE PRIMARY THREAT...SOME SEVERE...WITH THE STRONGER/ LONG-LIVED CELLS. ..PETERS.. 03/08/2011 ATTN...WFO...JAN...LIX...LZK...LCH...SHV... Link to comment Share on other sites More sharing options...
Jim Martin Posted March 8, 2011 Share Posted March 8, 2011 URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 42 NWS STORM PREDICTION CENTER NORMAN OK 110 PM CST TUE MAR 8 2011 THE NWS STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF LARGE PART OF CENTRAL AND SOUTHERN LOUISIANA LARGE PART OF SOUTHERN MISSISSIPPI COASTAL WATERS EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 110 PM UNTIL 800 PM CST. TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES WEST SOUTHWEST OF FORT POLK LOUISIANA TO 10 MILES EAST OF PINE BELT MISSISSIPPI. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2). REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. DISCUSSION...VERY MOIST/UNSTABLE AIR MASS SPREADING INLAND LWR MS VALLEY WHERE SHEAR PROFILES ALREADY FAVORABLE FOR SUPERCELLS. EXPECT THUNDERSTORMS TO DEVELOP AND INTENSIFY THRU THE AFTERNOON AS UPPER TROUGH AND STRONG JET APPROACH THE REGION. SUPERCELLS INCLUDING TORNADOES ARE LIKELY WITH THE POTENTIAL FOR A STRONG TORNADO BY LATER THIS AFTERNOON AND EVENING. AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 22035. ...HALES Link to comment Share on other sites More sharing options...
ksstormhunter Posted March 8, 2011 Share Posted March 8, 2011 Here is my latest analysis for the threat area. Right now showing far eastern Texas in the Longview, TX area up to Shreveport, LA corridor. Then two more areas of high threat potential for tornadoes is in the Lafayette, LA area and the third zone in the Baton Rouge area. Lafayette zone show high potential for F2 Type Tornado, 1.5" Hail potential and convective gusts around 64 knots. As for the Baton Rouge area showing a bit higher potential for an F3 type tornado with a tad bit more shear there, hail around 1" and convective gust around 61kts. Attached is the latest analysis. Any thoughts on this and in the Longview area, what are your thoughts for that area, more focused a bit further Southwest. Link to comment Share on other sites More sharing options...
Ed Lizard Posted March 8, 2011 Share Posted March 8, 2011 TORNADO WARNING LAC033-037-047-077-121-125-081945- /O.NEW.KLIX.TO.W.0012.110308T1902Z-110308T1945Z/ BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE NEW ORLEANS LA 102 PM CST TUE MAR 8 2011 THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A * TORNADO WARNING FOR... NORTHWESTERN EAST BATON ROUGE PARISH IN SOUTHEAST LOUISIANA... THIS INCLUDES THE CITIES OF...ZACHARY...BAKER... SOUTHWESTERN EAST FELICIANA PARISH IN SOUTHEAST LOUISIANA... THIS INCLUDES THE CITY OF JACKSON... NORTHWESTERN IBERVILLE PARISH IN SOUTHEAST LOUISIANA... SOUTHEASTERN POINTE COUPEE PARISH IN SOUTHEAST LOUISIANA... WEST BATON ROUGE PARISH IN SOUTHEAST LOUISIANA... SOUTHEASTERN WEST FELICIANA PARISH IN SOUTHEAST LOUISIANA... * UNTIL 145 PM CST * AT 101 PM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR RAMAH...OR 15 MILES WEST OF PLAQUEMINE...MOVING NORTHEAST AT 30 MPH. * OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO GROSSE TETE...MARINGOUIN...ERWINVILLE AND SLAUGHTER Link to comment Share on other sites More sharing options...
Ed Lizard Posted March 8, 2011 Share Posted March 8, 2011 Here is my latest analysis for the threat area. Right now showing far eastern Texas in the Longview, TX area up to Shreveport, LA corridor. Then two more areas of high threat potential for tornadoes is in the Lafayette, LA area and the third zone in the Baton Rouge area. Lafayette zone show high potential for F2 Type Tornado, 1.5" Hail potential and convective gusts around 64 knots. As for the Baton Rouge area showing a bit higher potential for an F3 type tornado with a tad bit more shear there, hail around 1" and convective gust around 61kts. Attached is the latest analysis. Any thoughts on this and in the Longview area, what are your thoughts for that area, more focused a bit further Southwest. How are these derived? Link to comment Share on other sites More sharing options...
blackjack123 Posted March 8, 2011 Share Posted March 8, 2011 Here is my latest analysis for the threat area. Right now showing far eastern Texas in the Longview, TX area up to Shreveport, LA corridor. Then two more areas of high threat potential for tornadoes is in the Lafayette, LA area and the third zone in the Baton Rouge area. Lafayette zone show high potential for F2 Type Tornado, 1.5" Hail potential and convective gusts around 64 knots. As for the Baton Rouge area showing a bit higher potential for an F3 type tornado with a tad bit more shear there, hail around 1" and convective gust around 61kts. Attached is the latest analysis. Any thoughts on this and in the Longview area, what are your thoughts for that area, more focused a bit further Southwest. What colors do those represent? Link to comment Share on other sites More sharing options...
Ed Lizard Posted March 8, 2011 Share Posted March 8, 2011 New MCD catches on to the clearing ahead of the Central Texas dryline. Hoping Mr. Reimer gets to chase in suitable territory. Link to comment Share on other sites More sharing options...
ksstormhunter Posted March 8, 2011 Share Posted March 8, 2011 How are these derived? This is a by product of my smartmodel which uses the forecast indicies, 23 to be exact and also incorporates Pireps, hourly surface observations, where it monitors pressure trends, dewpoint trends, temperature trends and is able to readjust some of the indicies, then each indicie is assinged a weight value and are tallied up. a 1.00 means all 23 indicies indicate severe or tornadoe potential along with forecasted shear, moisture in the mid to upper levels. Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted March 8, 2011 Share Posted March 8, 2011 Storm in Evangeline Parish will need to be watched, looking more organized Link to comment Share on other sites More sharing options...
ksstormhunter Posted March 8, 2011 Share Posted March 8, 2011 What colors do those represent? Sorry I cutoff the data key. the Green is Marginal with (50-60kts/.75-1/5" Hail/F1 Tornado Potential) Oranges is MDT (60-75KTS/1.5"-2" Hail/F2-F3 Tornado Potential) Red is High (75-85KTS/2-3" Hail/F3-F4 Tornado Potential) Purple is 85KTS+/3"+ Hail or F5+ Tornado Potential Link to comment Share on other sites More sharing options...
New England Storm Posted March 8, 2011 Share Posted March 8, 2011 Storm in Evangeline Parish will need to be watched, looking more organized Has a little bit of hook on it. Link to comment Share on other sites More sharing options...
thewxmann Posted March 8, 2011 Share Posted March 8, 2011 Thunderstorm initiation underway in N. TX in vicinity of subtle boundary intersections as dynamic forcing begins to encroach on warm sector. Link to comment Share on other sites More sharing options...
Jim Martin Posted March 8, 2011 Share Posted March 8, 2011 URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 43 NWS STORM PREDICTION CENTER NORMAN OK 135 PM CST TUE MAR 8 2011 THE NWS STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF PARTS OF SOUTHWEST ARKANSAS SOUTHEAST OKLAHOMA PARTS OF NORTH CENTRAL AND NORTHEAST TEXAS EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 135 PM UNTIL 800 PM CST. TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH NORTHEAST OF MCALESTER OKLAHOMA TO 85 MILES SOUTH OF PARIS TEXAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3). REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. OTHER WATCH INFORMATION...CONTINUE...WW 42... DISCUSSION...AIR MASS ALONG AND E OF N/S DRY LINE HAS DESTABILIZED WITH MLCAPES AOA 1500 J/KG WITH FAVORABLE SHEAR PROFILES IN PLACE FOR SUPERCELLS. THUNDERSTORMS ARE DEVELOPING ALONG DRY LINE AND WILL INCREASE IN NUMBER AND INTENSITY THRU THE AFTERNOON AS THEY MOVE EWD. WHILE LARGE HAIL IS LIKELY WITH ANY SUPERCELL...A TORNADO THREAT IS ALSO EXPECTED GIVEN THE STRONG MID/UPPER SHEAR ACROSS THE AREA AHEAD OF UPPER TROUGH. AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 24030. ...HALES Link to comment Share on other sites More sharing options...
blackjack123 Posted March 8, 2011 Share Posted March 8, 2011 Sorry I cutoff the data key. the Green is Marginal with (50-60kts/.75-1/5" Hail/F1 Tornado Potential) Oranges is MDT (60-75KTS/1.5"-2" Hail/F2-F3 Tornado Potential) Red is High (75-85KTS/2-3" Hail/F3-F4 Tornado Potential) Purple is 85KTS+/3"+ Hail or F5+ Tornado Potential So everything is game today? Link to comment Share on other sites More sharing options...
thewxmann Posted March 8, 2011 Share Posted March 8, 2011 So everything is game today? Not necessarily. A Smartmodel's not going to catch all the mesoscale nuances. Nor do indexes tell you the whole picture. For instance, Mesoanalysis shows 50kt of Bulk shear in SE LA, but d(wind velocity) between 850 and 500mb is nearly zero. And as a result, note that all the storms in SE LA thus far have failed to remain discrete. The "high risk" purple area in east central TX is lodged in an area of subsidence between the two areas of forcing/convection in LA and N Ctrl TX. I'm not trying to diss on the smartmodel, but I'm trying to make a point - like any other model, it is just guidance. Good to have to look at, but look at the bigger picture. Link to comment Share on other sites More sharing options...
ksstormhunter Posted March 8, 2011 Share Posted March 8, 2011 So everything is game today? From the looks of it, I believe so seeing those Surface Based CAPE values pushing over a 1000 (j/kg) in addition to the MLCAPE above 1000, STP around 4 to 6 and SCP around 7. Also looking at the 0-3KM Shear close to 40kts. Link to comment Share on other sites More sharing options...
Ed Lizard Posted March 8, 2011 Share Posted March 8, 2011 What is the convective parameterization scheme of SmartModel? How many vertical levels does it have and what is the effective horizontal resolution? Link to comment Share on other sites More sharing options...
hm8 Posted March 8, 2011 Share Posted March 8, 2011 Nice rotation on this cell south of Greesnburg, LA Link to comment Share on other sites More sharing options...
SmokeEater Posted March 8, 2011 Share Posted March 8, 2011 Nice rotation on this cell south of Greesnburg, LA Does everything rotate when it gets near a Greensburg? I was wondering when that big blob of a supercell would finally start rotating. BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE NEW ORLEANS LA 256 PM CST TUE MAR 8 2011 THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A * TORNADO WARNING FOR... SOUTHERN ST. HELENA PARISH IN SOUTHEAST LOUISIANA... THIS INCLUDES THE CITY OF GREENSBURG... NORTHERN TANGIPAHOA PARISH IN SOUTHEAST LOUISIANA... THIS INCLUDES THE CITY OF AMITE... NORTHWESTERN WASHINGTON PARISH IN SOUTHEAST LOUISIANA... SOUTHERN PIKE COUNTY IN SOUTHERN MISSISSIPPI... * UNTIL 330 PM CST * AT 252 PM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR MONTPELIER...OR 8 MILES SOUTH OF GREENSBURG...MOVING NORTHEAST AT 35 MPH. * OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ROSELAND...KENTWOOD...WILMER...OSYKA AND MOUNT HERMAN. Link to comment Share on other sites More sharing options...
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