Moderate Risk of Severe Weather LA and MS
Posted by JAC on 3/8/2011, 2:11 pm
 ZCZC SPCPWOSPC ALL WOUS40 KWNS 081709 LAZ000-MSZ000-090200- PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1109 AM CST TUE MAR 08 2011 ...SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF THE LOWER MISSISSIPPI VALLEY LATER TODAY AND TONIGHT... THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE DEVELOPMENT OF A FEW STRONG TORNADOES OVER PARTS OF THE LOWER MISSISSIPPI VALLEY LATER TODAY AND TONIGHT. THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE MOST OF LOUISIANA SOUTHERN MISSISSIPPI ELSEWHERE...SEVERE STORMS ARE ALSO POSSIBLE FROM EASTERN OKLAHOMA AND TEXAS INTO SOUTHERN MISSOURI...ARKANSAS...NORTHERN MISSISSIPPI AND WESTERN ALABAMA. AN UPPER-LEVEL STORM SYSTEM CENTERED OVER THE CENTRAL AND SOUTHERN HIGH PLAINS WILL MOVE EASTWARD INTO THE MIDDLE MISSISSIPPI VALLEY THROUGH TONIGHT. STRONG SOUTH WINDS JUST ABOVE THE SURFACE WILL RESULT IN A WARM AND MOIST AIR MASS OVER THE WESTERN GULF OF MEXICO TO STREAM NORTHWARD ACROSS THE LOWER MISSISSIPPI VALLEY AS A WARM FRONT SHIFTS TO THE NORTHEAST. LIFT ASSOCIATED WITH THE WARM FRONT AND THE UPPER-LEVEL SYSTEM WILL RESULT IN SCATTERED THUNDERSTORMS THIS AFTERNOON BECOMING MORE NUMEROUS THIS EVENING INTO THE OVERNIGHT. THE GREATEST RISK FOR STRONG TORNADOES WILL BE LATE THIS AFTERNOON THROUGH TONIGHT ACROSS MOST OF LOUISIANA INTO SOUTHERN MISSISSIPPI. STATE AND LOCAL EMERGENCY MANAGERS ARE MONITORING THIS DEVELOPING SITUATION. THOSE IN THE THREATENED AREA ARE URGED TO REVIEW SEVERE WEATHER SAFETY RULES AND TO LISTEN TO RADIO...TELEVISION...AND NOAA WEATHER RADIO FOR POSSIBLE WATCHES...WARNINGS...AND STATEMENTS LATER TODAY. ..GRAMS.. 03/08/2011  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 |
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In this thread:
- Significant Tornado Potential around MS Delta - JAC, 3/8/2011, 3:08 pm
- Re: Moderate Risk of Severe Weather LA and MS - ArgosyTn, 3/8/2011, 2:28 pm
- Latest SREF - JAC, 3/8/2011, 2:18 pm
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