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 011233
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0733 AM CDT WED JUN 01 2011
   
   VALID 011300Z - 021200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO THIS EVENING FROM
   NEW ENGLAND TO THE MID ATLANTIC STATES...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR
   PARTS OF THE SRN/CENTRAL HIGH PLAINS...
   
   ...NE AND MID ATLANTIC STATES TODAY...
   AN INITIAL SPEED MAX IS ROTATING NEWD OVER WRN QUEBEC...WHILE THE
   PRIMARY MIDLEVEL TROUGH OVER ONTARIO WILL PROGRESS EWD OVER NRN
   NY/NEW ENGLAND LATER THIS AFTERNOON INTO TONIGHT.  AN ASSOCIATED
   SURFACE COLD FRONT...TRAILING SWD FROM THE OCCLUDED LOW IN
   QUEBEC...WILL MOVE EWD ACROSS NEW ENGLAND BY EARLY TONIGHT...AND
   SEWD INTO THE MID ATLANTIC REGION LATE TONIGHT.
   
   A BROKEN BELT OF THUNDERSTORMS ASSOCIATED WITH LOW-LEVEL WAA WILL
   SPREAD EWD ACROSS NEW ENGLAND THIS MORNING...WITH THE POTENTIAL FOR
   MARGINALLY SEVERE HAIL IN THE STRONGER STORMS.  THE WARM SECTOR WILL
   SPREAD EWD/NEWD IN THE WAKE OF THE MORNING WAA STORMS...SETTING THE
   STAGE FOR ADDITIONAL THUNDERSTORM DEVELOPMENT LATER THIS MORNING
   INTO THIS AFTERNOON ALONG THE COLD FRONT WHICH IS NOW MOVING INTO NE
   OH AND WRN NY.  IN ADVANCE OF THE FRONT...BOUNDARY LAYER DEWPOINTS
   IN THE UPPER 60S AND SURFACE TEMPERATURES WARMING INTO THE UPPER 70
   TO LOW 80S WILL SUPPORT MLCAPE VALUES OF 1500-2500 J/KG WITH LITTLE
   CONVECTIVE INHIBITION.  LARGELY UNIDIRECTIONAL WIND PROFILES WITH
   50-70 KT WLY/WSWLY FLOW WILL COMBINE WITH THE MODERATE INSTABILITY
   TO SUPPORT A RISK FOR ORGANIZED CLUSTERS/LINE SEGMENTS...AS WELL AS
   A FEW SUPERCELLS.  DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREAT
   THIS AFTERNOON...THOUGH INSTABILITY WILL ALSO BE SUFFICIENT FOR
   LARGE HAIL WITH THE STRONGER STORMS.  A COUPLE OF TORNADOES WILL
   ALSO BE POSSIBLE ACROSS NEW ENGLAND WHERE 0-1 KM SRH IS FORECAST TO
   EXCEED 150-200 M2/S2 AND THE BOUNDARY LAYER WILL REMAIN FAVORABLY
   MOIST.
   
   THUNDERSTORMS WILL ALSO DEVELOP SWWD ALONG AND IN ADVANCE OF THE
   COLD FRONT THIS AFTERNOON INTO VA/NC.  HIGHS IN THE 90S AND
   DEWPOINTS IN THE MID-UPPER 60S WILL CONTRIBUTE TO STRONG INSTABILITY
   /MLCAPE NEAR 3000 J PER KG/...BUT VERTICAL SHEAR WILL WEAKEN
   CONSIDERABLY WITH SWD EXTENT.  THUS...MULTICELL CLUSTERS SHOULD BE
   THE PRIMARY CONVECTIVE MODE ACROSS THIS AREA...WITH AN ATTENDANT
   RISK FOR ISOLATED DOWNBURSTS AND LARGE HAIL.
   
   ...SRN AND CENTRAL HIGH PLAINS THROUGH TONIGHT...
   A SURFACE WARM FRONT ACROSS OK THIS MORNING WILL MOVE NWD TO NEB
   THIS EVENING AND SD OVERNIGHT...IN RESPONSE TO LEE CYCLOGENESIS
   ACROSS THE NRN HIGH PLAINS.  THE CYCLOGENESIS WILL OCCUR DOWNSTREAM
   FROM A DEEP MIDLEVEL TROUGH THAT WILL BEGIN TO EJECT ENEWD FROM NRN
   CA/ORE THIS MORNING TO NV/ID/UT BY LATE TONIGHT.
   
   SOME ELEVATED CONVECTION IS ONGOING THIS MORNING IN THE ZONE OF
   STRONGEST WAA NEAR THE OK/KS BORDER...WHILE CONSIDERABLE DEBRIS
   CLOUDINESS IS PRESENT FROM SW TX INTO OK...WITH A REMNANT MCV ALONG
   THE RED RIVER W OF SPS.  BOUNDARY LAYER DEWPOINTS IN THE 50S HAVE
   SPREAD NWWD WELL INTO ERN NM...AND SHOULD CONTINUE NWD INTO ERN
   CO...WHILE THE 68-70 F DEWPOINTS IN OK WILL MOVE NWD INTO KS/NEB. 
   THOUGH SOME MIXING OF LOW-LEVEL MOISTURE IS EXPECTED ACROSS THE HIGH
   PLAINS...STRONG SURFACE HEATING WILL RESULT IN MODERATE INSTABILITY
   AND SUPPORT SCATTERED THUNDERSTORM DEVELOPMENT IN THE SLIGHT RISK
   AREA THIS AFTERNOON.  VERTICAL SHEAR WILL BE MORE FAVORABLE FOR
   SUPERCELLS FARTHER N INTO KS/NEB IN PROXIMITY TO THE STRONGER
   MIDLEVEL FLOW...THOUGH RECENT NAM FCSTS APPEAR TO BE OVERESTIMATING
   LOW-LEVEL SHEAR IN RESPONSE TO CONVECTIVE PROCESSES IN THE MODEL. 
   LARGE HAIL AND ISOLATED DAMAGING GUSTS WILL BE THE MAIN SEVERE
   THREATS...THOUGH A TORNADO OR TWO CANNOT BE RULED OUT THIS EVENING
   INVOF THE WARM FRONT IN NW KS/SW NEB WHERE LOW-LEVEL SHEAR WILL BE
   STRONGER AND THE LOW LEVELS WILL BE SUFFICIENTLY MOIST.
   
   ...ND TO IA/MO OVERNIGHT...
   LOW-LEVEL MOISTURE WILL SPREAD NWD/NEWD AND INSTABILITY WILL
   INCREASE ON THE NOSE OF A 35-50 KT SSWLY LLJ.  STEEP LAPSE RATES AND
   MODERATE ELEVATED INSTABILITY COULD SUPPORT ISOLATED LARGE HAIL WITH
   THE STRONGEST STORMS FROM ABOUT 06-12Z...THOUGH THE ZONE OF
   RELATIVELY UNCAPPED INSTABILITY SHOULD REMAIN NARROW.  WITH THE
   MAGNITUDE OF THE HAIL THREAT IN QUESTION AND LATE IN THE
   PERIOD...WILL MAINTAIN 5% PROBABILITIES.
   
   ...CENTRAL/N FL TODAY...
   A WELL-DEVELOPED AND LONG-LIVED MCV WITH PERSISTENT CONVECTIVE BANDS
   WILL CONTINUE WSWWD AND REACH THE COAST NEAR DAYTONA BEACH AROUND
   16Z.  INSTABILITY WILL NOT BE PARTICULARLY STRONG...BUT ENHANCED
   GRADIENT FLOW ACCOMPANYING THIS SYSTEM WILL SUPPORT A RISK FOR
   ISOLATED DAMAGING WINDS IN THE ORGANIZED BANDED STRUCTURES.
   
   ..THOMPSON/GARNER.. 06/01/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z