Mar 31, 2008 1300 UTC Day 1 Convective Outlook
Updated: Mon Mar 31 13:01:15 UTC 2008
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Categorical Graphic
20080331 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20080331 1300 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20080331 1300 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20080331 1300 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 311257
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0757 AM CDT MON MAR 31 2008
   
   VALID 311300Z - 011200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS TODAY FOR ERN OK...SW MO...WRN
   AR...AND NE TX...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK...FROM
   CENTRAL TX NEWD TO SE IA/IL...
   
   ...SYNOPSIS...
   A SURFACE CYCLONE NOW IN KS WILL DEVELOP NEWD ALONG A RETREATING
   BAROCLINIC ZONE TO SRN IA BY MIDDAY...EXTREME SW WI THIS
   EVENING...AND NRN LOWER MI LATE TONIGHT IN ADVANCE OF THE PRIMARY
   MID LEVEL TROUGH NOW EJECTING NEWD FROM CO/NM.  SURFACE ANALYSES
   CONFIRM THAT THE RICHER LOW-LEVEL MOISTURE IN THE WARM SECTOR WILL
   LIKELY BE CONFINED TO AREAS FROM IL/MO/AR/LA WWD INTO OK/TX...WITH
   THE ERN EXTENT OF THE MOISTURE LIMITED BY TRAJECTORIES EMANATING
   FROM WITHIN THE ERN US SURFACE RIDGE.  THESE RELATIVELY DRIER
   LOW-LEVEL TRAJECTORIES...ALONG WITH THE LINGERING INFLUENCE OF
   YESTERDAY/S CONVECTION ACROSS AR/LA/E TX AND THE ONGOING CONVECTIVE
   CLUSTERS IN MO/IA AND NE OK...CAST DOUBT ON THE DEGREE OF
   INSTABILITY IN THE WARM SECTOR TODAY FROM CENTRAL MO NEWD TO SE
   IA/IL/SRN WI.  MEANWHILE...SUBSTANTIALLY GREATER INSTABILITY APPEARS
   LIKELY TODAY FROM CENTRAL/ERN OK SWD INTO TX ALONG THE AXIS OF 65-70
   F BOUNDARY LAYER DEWPOINTS...ALONG WITH THE GREATER SEVERE STORM
   RISK.
   
   ...OK/SW MO/AR/CENTRAL AND ERN TX TODAY INTO TONIGHT...
   LATEST OBSERVED DATA/CONVECTIVE TRENDS...AND THE MAJORITY OF THE
   SHORT TERM MODEL GUIDANCE...SUGGEST THAT THE PRIMARY SEVERE STORM
   THREAT CORRIDOR TODAY WILL LIKELY BE CONFINED TO AREAS ALONG AND E
   OF I-44 IN MO/OK/WRN AR...WITH A MORE ISOLATED THREAT E OF I-35 IN
   SRN OK/TX.  THE RESIDUAL PLUME OF STEEP MID LEVEL LAPSE RATES AND AN
   UNCONTAMINATED/MOIST BOUNDARY LAYER WILL REMAIN CO-LOCATED TODAY
   FROM CENTRAL/ERN OK SWWD INTO CENTRAL/E TX...WHERE MLCAPE VALUES
   SHOULD RANGE FROM 1500-3000 J/KG.  SOME LOW-LEVEL WARMING/MOISTENING
   IS ALSO EXPECTED ACROSS AT LEAST WRN AR INTO SW/CENTRAL MO ON THE
   SRN FRINGE OF THIS MORNING/S CONVECTIVE CLUSTER.  
   
   EXPECT SEVERE THUNDERSTORMS TO DEVELOP BY MID MORNING TO EARLY
   AFTERNOON ALONG THE COLD FRONT MOVING SEWD INTO CENTRAL/NE OK...AND
   NE OF THE DRYLINE/COLD FRONT TRIPLE POINT IN CENTRAL OK.  THIS
   BOUNDARY INTERSECTION SHOULD DEVELOP SWD INTO N TX OVERNIGHT...WITH
   THUNDERSTORMS CONTINUING ALONG THE COLD FRONT.  OTHER THUNDERSTORM
   DEVELOPMENT MAY OCCUR SE OF THE FRONT AND E OF THE DRYLINE DURING
   THE DAY FROM NE TX NWD ACROSS ERN OK/WRN AR INTO MO...AND ALONG THE
   RESIDUAL BOUNDARY WITH THE NE OK STORMS.  THE COMBINATION OF
   MODERATE INSTABILITY AND 0-6 KM BULK SHEAR OF AT LEAST 50 KT WILL
   SUPPORT A FEW SUPERCELLS WITHIN THE LARGER CONVECTIVE BAND.  THE
   MORE INTENSE/DISCRETE STORMS WILL BE CAPABLE OF PRODUCING VERY LARGE
   HAIL AND A STRONG TORNADO OR TWO THROUGH THIS EVENING...GIVEN A
   MOIST BOUNDARY LAYER AND EFFECTIVE SRH AOA 250-300 M2/S2.  THE
   SEVERE THREAT SHOULD GRADUALLY DIMINISH LATER TONIGHT AS THE
   BOUNDARY LAYER COOLS AND THE STRONGER LOW-LEVEL FLOW/SHEAR DEVELOPS
   NEWD AWAY FROM THE INSTABILITY AXIS.  
   
   ...NRN MO/SE IA/IL/SRN WI TODAY...
   INSTABILITY WILL LIKELY REMAIN SOMEWHAT LIMITED CLOSER TO THE
   SURFACE LOW TRACK...AS A RESULT OF THE ONGOING CONVECTION IN NE
   OK/SE KS/SW MO...AND THE PREVIOUSLY MENTIONED DRIER LOW-LEVEL AIR
   MASS FROM ERN AR/MO EWD.  WIDESPREAD CLOUDS WILL TEND TO LIMIT
   SURFACE HEATING ACROSS MOST OF THE AREA...WHILE BOUNDARY LAYER
   DEWPOINTS SHOULD RANGE FROM 58-62 F.  STILL...VERTICAL SHEAR WILL BE
   STRONG AND SUPERCELLS/TORNADOES WILL BE POSSIBLE IF THE SURFACE CAN
   WARM A LITTLE MORE THAN CURRENTLY EXPECTED NEAR THE WARM FRONT THIS
   AFTERNOON.
   
   ...CENTRAL TX THIS AFTERNOON/EVENING...
   ISOLATED THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ALONG THE DRYLINE
   THIS AFTERNOON ACROSS CENTRAL TX...WHERE MODERATE INSTABILITY AND
   DEEP LAYER SHEAR ARE EXPECTED ALONG THE SRN FRINGE OF THE STRONGER
   MID LEVEL FLOW.  ISOLATED SUPERCELLS WILL BE POSSIBLE...WITH LARGE
   HAIL THE PRIMARY THREAT.
   
   ..THOMPSON/SMITH.. 03/31/2008
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z