Categorical Graphic
Probabilistic Tornado Graphic
Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Probabilistic Damaging Wind Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Probabilistic Large Hail Graphic
Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.

   SPC AC 240554
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1254 AM CDT SUN APR 24 2011
   
   VALID 241200Z - 251200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS CORRIDOR FROM PORTIONS SW TX
   AND OK TO MID-ATLANTIC...
   
   ...SYNOPSIS...
   STG MID-UPPER LEVEL SPEED MAX AND ATTENDANT LOW-AMPLITUDE SHORTWAVE
   TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY APCHG NRN CA COAST
   -- ARE FCST TO MOVE SEWD ACROSS CA/GREAT BASIN DURING
   PERIOD...LEADING TO HEIGHT FALLS AND AMPLIFICATION OF TROUGHING
   ACROSS WRN CONUS.  DURING 25/00Z-25/12Z TIME FRAME...RESULTANT
   TROUGH SHOULD MOVE EWD FROM UT/AZ ACROSS NM AND MUCH OF
   CO...REACHING CENTRAL/SRN HIGH PLAINS BY END OF PERIOD. 
   FOREGOING/WEAKER SHORTWAVE TROUGH -- NOW APPARENT OVER SERN CA/WRN
   AZ/NWRN SONORA REGION -- WILL MOVE NEWD TO NEAR TX PANHANDLE AND
   PERMIAN BASIN REGIONS BY LATE AFTERNOON.
   
   AHEAD OF THIS PROCESS...BROAD BELT OF SW FLOW ALOFT WILL EXTEND FROM
   SRN HIGH PLAINS TO MID-ATLANTIC STATES...LARGELY PARALLEL TO
   PERSISTENT SFC FRONT.  FRONTAL ZONE SHOULD REMAIN ACROSS CORRIDOR
   FROM NJ AND CENTRAL APPALACHIANS SWWD ACROSS KY...AR...SERN OK AND N
   TX.  EFFECTIVE FRONTAL ZONE MAY BE SHUNTED SWD ANYWHERE ALONG ITS
   EXTENT BY MCS OUTFLOWS.  BY MID-LATE AFTERNOON...FRONT/DRYLINE
   INTERSECTION SHOULD RESIDE IN GEN AREA BETWEEN ABI SPS WITH DRYLINE
   SWD TOWARD SERRANIAS DEL BURRO AREA OF NRN COAHUILA.
   
   ...TX/OK/AR PORTION OF OUTLOOK AREA -- DRYLINE/FRONT...
   TSTMS ARE EXPECTED TO DEVELOP DURING AFTERNOON ALONG FRONT AND
   DRYLINE...BECOMING MORE DENSE/NUMEROUS OVER FRONT GIVEN NEARLY
   PARALLEL NATURE OF MEAN WIND AND DEEP-SHEAR VECTORS...LEADING TO
   EARLY TRANSITION TO MESSY CONVECTIVE MODES.  MORE ORTHOGONAL
   COMPONENT OF FLOW ALOFT ACROSS DRYLINE...COMPARED TO COLD
   FRONT...SHOULD SUPPORT MORE DISCRETE STORMS...INCLUDING
   SUPERCELLS...FROM NEAR TRIPLE POINT SWD.  THIS ACTIVITY SHOULD
   PRODUCE LARGE HAIL...WITH HAILSTONES AOA 2.75 INCH DIAMETER LIKELY
   IN A FEW SUPERCELLS.  ENHANCED SRH AND DEEP-LAYER SHEAR ALONG THAT
   PART OF FRONT NEAR DRYLINE MAY AID TORNADO POTENTIAL...WHICH ALSO
   WILL EXIST SOMEWHAT SWD AHEAD OF DRYLINE INTO EARLY EVENING AS LLJ
   ENLARGES 0-1 KM AGL HODOGRAPHS.
   
   INCREASING HEIGHT FALLS...DCVA...AND STRENGTHENING 500-250 MB LAYER
   WINDS ARE ALL EXPECTED OVER WRN PORTIONS OF THIS REGION DURING
   AFTERNOON AHEAD OF EJECTING SHORTWAVE TROUGH...CONCURRENT WITH STG
   SFC HEATING AND FAVORABLE BUOYANCY.  MLCAPE 2500-3000 J/KG IS
   POSSIBLE...AMIDST 40-50 KT EFFECTIVE SHEAR.
   
   GRADUAL NWD SHIFT IN GREATEST CONVECTIVE CONCENTRATION AGAIN IS
   LIKELY OVERNIGHT...AS STG LOW-LEVEL WAA AND ISENTROPIC ASCENT TO LFC
   OCCUR N OF SFC FRONT.  MAIN CONCERN N OF FRONT OVERNIGHT WILL BE
   LARGE HAIL.
   
   ....MS VALLEY TO MID-ATLANTIC REGION -- FRONTAL REGIME...
   EPISODIC TSTM DEVELOPMENT/INTENSIFICATION IS POSSIBLE THROUGHOUT
   DAY...PERHAPS INCLUDING RE-INTENSIFICATION OF MORNING CONVECTION
   CARRYING OVER FROM PRIOR PERIOD.  MAIN THREAT IS DAMAGING
   WIND...THOUGH LARGE HAIL ALSO MAY OCCUR.  MORE SPECIFIC
   CONCENTRATIONS OF SVR POTENTIAL WITHIN THIS CORRIDOR ARE
   LIKELY...BUT WILL DEPEND ON MESOSCALE EFFECTS YET TO BECOME APPARENT
   SUCH AS MCV ACTIVITY...OUTFLOW INTERACTIONS...AND POCKETS OF
   ENHANCED DIABATIC HEATING RELATED TO CLOUD BREAKS.  DOMINANT
   CONVECTIVE MODE SHOULD BE BOWS/CLUSTERS AMIDST NEARLY UNIDIRECTIONAL
   DEEP-TROPOSPHERIC FLOW.  GENERALLY WEAKER LAPSE RATES WITH EWD
   EXTENT WILL REDUCE BUOYANCY...HOWEVER WEAK CAPPING ALSO WILL AID IN
   POTENTIAL FOR SFC-BASED TSTMS.  SVR THREAT SHOULD END DURING
   EVENING.
   
   ..EDWARDS/ROGERS.. 04/24/2011
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z