Feb 24, 2011 0600 UTC Day 1 Convective Outlook
Updated: Thu Feb 24 09:32:43 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...severe thunderstorms expected over parts of the lower mississippi...lower tennessee...and lower ohio valleys later today into tonight....   Please read the latest public statement about this event.

Categorical Graphic
20110224 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20110224 1200 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20110224 1200 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20110224 1200 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 240545
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1145 PM CST WED FEB 23 2011
   
   VALID 241200Z - 251200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS OVER CNTRL AND ERN AR...WRN
   TN...SMALL PART OF SERN MO...NRN MS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ERN PARTS OF THE SRN PLAINS TO
   THE LWR OH VLY...LWR MS VLY...MID-SOUTH...
   
   ...SYNOPSIS...
   FORMIDABLE MID-LEVEL SHORTWAVE TROUGH CURRENTLY OVER THE DESERT SW
   IS EXPECTED TO EJECT ENE ACROSS THE CNTRL/SRN PLAINS THIS AFTERNOON
   AND ACROSS THE LOWER/MID-MS VLY BY TONIGHT.  IN THE LOWER LEVELS...A
   LOW OVER WCNTRL OK EARLY THIS MORNING WILL INTENSIFY AND MIGRATE
   INTO SRN MO BY LATE AFTERNOON AND TO THE MID-OH VLY BY 12Z/25.  TO
   THE E OF THE LOW...A WARM FRONT WILL ADVANCE NWD TO ALONG THE MO/AR
   BORDER BY LATE MORNING AND THE OH VLY LATER IN THE DAY.  A
   PRE-FRONTAL TROUGH WILL MOVE EWD FROM E TX/OK EARLY IN THE DAY TO
   THE MID-SOUTH AND TN VLY BY TONIGHT.
   
   ...ERN OK/TX EWD INTO THE MID-SOUTH/TN VLY...
   STRONG SLY LOW-LEVEL FLOW IN ADVANCE OF THE APPROACHING MID-LEVEL
   WAVE WILL TRANSPORT LOWER AND MIDDLE 60S SFC DEW POINTS AS FAR N AS
   ERN OK...NRN AR AND WRN TN/KY AHEAD OF THE ADVANCING PRE-FRONTAL
   TROUGH TODAY.  THIS WILL CONTRIBUTE TO SUFFICIENT INSTABILITY TO
   SUPPORT A WIDESPREAD TSTM THREAT AS 90-120 METER MID-LEVEL HEIGHT
   FALLS SPREAD ENE TODAY AND TONIGHT ACROSS THE SRN PLAINS TO THE
   MID-SOUTH/TN VLY.
   
   TSTMS WILL INCREASE IN THE PRE-DAWN HOURS OVER PORTIONS OF WRN
   OK/NWRN TX NEAR THE SFC LOW AND DRYLINE/TROUGH AS THE LARGE-SCALE
   ASCENT/STEEP MID-LEVEL LAPSE RATES BEGIN TO IMPACT WRN PERIPHERY OF
   MOIST PLUME.  THE STORMS WILL LIKELY PRODUCE HAIL DURING THE MORNING
   HOURS OVER CNTRL OK AND NCNTRL TX OWING TO FAVORABLE MID-LEVEL LAPSE
   RATE ENVIRONMENT.
   
   THE MORNING STORMS WILL LIKELY INTENSIFY WITH ADDITIONAL SFC-BASED
   ACTIVITY SPROUTING DURING THE LATE MORNING/AFTERNOON FROM NERN TX
   INTO WRN/CNTRL AR ALONG THE PRE-FRONTAL TROUGH.  THESE STORMS WILL
   PROBABLY OFFER THE BEST OPPORTUNITY FOR HIGHER-IMPACT SEVERE THREATS
   AS THEY MATURE OVER NRN LA...CNTRL/ERN AR...NWRN MS AND WRN TN
   DURING THE LATE AFTERNOON-MID-EVENING HOURS.  SSWLY 850 MB FLOW IN
   EXCESS OF 55 KTS BENEATH INCREASING SWLY MID-LEVEL FLOW WILL BOOST
   OVERALL DEEP-LAYER SHEAR FOR SUPERCELLS.  DISCRETE STORMS THAT
   DEVELOP CLOSE TO THE WARM FRONT...LIKELY IN CNTRL/NERN AR AND WRN
   TN...WILL BE EMBEDDED IN 200-300 M2/S2 0-1KM SRH AND WILL OFFER THE
   GREATEST OPPORTUNITY FOR STRONG TORNADOES.
   
   ACTIVITY SHOULD EVOLVE INTO A QLCS DURING THE MID-EVENING AND MOVE
   QUICKLY ENE INTO THE TN VLY/DEEP SOUTH OVERNIGHT.  THERE WILL REMAIN
   A THREAT FOR DAMAGING WINDS/HAIL WELL INTO THE NIGHT...ESPECIALLY
   OVER PARTS OF MIDDLE TN...MS AND WRN AL.  GIVEN THAT THE STRONG
   FORCING WILL EJECT NEWD TOWARD THE OH VLY...ISOLD DMGG WIND GUSTS
   WILL BE POSSIBLE AS FAR N AS THE OH RVR AS WELL...THOUGH BETTER
   INSTABILITY WILL BE FARTHER S.
   
   ..RACY/COHEN.. 02/24/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z