Mar 8, 2009 2000 UTC Day 1 Convective Outlook
Updated: Sun Mar 8 19:38:21 UTC 2009
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Categorical Graphic
20090308 2000 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20090308 2000 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20090308 2000 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20090308 2000 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 081934
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0234 PM CDT SUN MAR 08 2009
   
   VALID 082000Z - 091200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER
   MUCH OF THE OH VALLEY...
   
   ...OH VALLEY INTO ARKLATEX...
   
   DYNAMIC MIDLEVEL TROUGH AND ASSOCIATED 90-100 KT JET STREAK OVER THE
   MID MS VALLEY WILL CONTINUE NEWD INTO THE LOWER GREAT LAKES REGION
   BY MONDAY MORNING.  ASSOCIATED SURFACE LOW OVER NERN IL HAS LIKELY
   BOTTOMED IN CENTRAL PRESSURE WITH A SLOW FILLING FORECAST AS IT
   DEVELOPS NEWD INTO WRN NY BY 09/12Z.  MEANWHILE...TRAILING COLD
   FRONT WILL PUSH EWD THROUGH THE OH VALLEY WITH WRN EXTENSION OF THIS
   BOUNDARY STALLING AND EVENTUALLY LIFTING NWD INTO THE ARKLATEX LATER
   TONIGHT.
   
   CLUSTERS OF SEVERE TSTMS ARE ONGOING AS OF 19Z FROM VICINITY OF
   SURFACE LOW OVER FAR NERN IL/NWRN IND SWD ALONG COLD FRONT INTO WRN
   KY...FORCED BY STRONG DEEP LAYER ASCENT IN ADVANCE OF MIDLEVEL
   TROUGH.  RADAR DEPICTION OF STORMS SUGGESTS THAT A RATHER DEEP LAYER
   OF REAR-TO-FRONT STORM-RELATIVE FLOW HAS ALLOWED STORMS TO REMAIN
   SOMEWHAT MORE DISCRETE OVER IND WITH A MORE LINEAR MODE NEAR PAH
   WHERE SURFACE FRONT HAS BECOME ALIGNED LARGELY PARALLEL TO THE
   DEEP-LAYER SHEAR VECTOR.
   
   CONSIDERABLE CLOUDINESS WITHIN PRE-FRONTAL WARM SECTOR HAS LIMITED
   DAYTIME HEATING N OF THE OH RIVER WITH TEMPERATURES LARGELY IN THE
   6OS AND RESULTANT MLCAPE AOB 500 J/KG.  FARTHER S...WARMER AND MORE
   MOIST BOUNDARY LAYER CONDITIONS EXIST...BUT WEAK MIDLEVEL LAPSE
   RATES ARE LIMITING MLCAPE TO LESS THAN 250-500 J/KG PER 18Z LIT/SHV
   SOUNDINGS.
   
   DESPITE THE MARGINAL INSTABILITY...EXPECT THE STRONG AND DEEP
   DYNAMIC FORCING FOR ASCENT TO MAINTAIN BROKEN CONVECTIVE LINE EWD
   ACROSS THE REMAINDER OF THE OH VALLEY THIS AFTERNOON INTO TONIGHT. 
   WHILE DAMAGING WINDS WILL REMAIN THE PRIMARY THREAT...ISOLATED
   TORNADO POTENTIAL WILL REMAIN MAXIMIZED ACROSS IND THROUGH ABOUT
   21Z.  HERE...A STRONG ISALLOBARIC SURFACE GRADIENT IS MAINTAINING A
   CORRIDOR OF ENHANCED LOW-LEVEL SHEAR ALONG AND SE OF SURFACE LOW
   TRACK.
   
   FARTHER S...THERE STILL REMAINS SOME QUESTION HOW FAR S/SW STORMS
   WILL DEVELOP ALONG FRONT.  MODEL GUIDANCE CONTINUES TO SUGGEST THAT
   DEEPER MOIST CONVECTION WHICH HAS PERSISTED TODAY OVER SRN AR MAY
   EVENTUALLY EVOLVE INTO SUSTAINED STORMS TONIGHT OVER WRN TN/NRN MS. 
   HOWEVER...CONCERNS DO EXIST GIVEN THE 18Z LIT/SHV SOUNDINGS AND
   RAPIDLY WEAKENING UVV WITH PASSAGE OF UPPER SYSTEM TO THE NE.  BASED
   ON THIS UNCERTAINTY...ONLY LOW SEVERE WEATHER PROBABILITIES WILL BE
   MAINTAINED ACROSS THIS REGION.
   
   ..MEAD.. 03/08/2009
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z