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 111638
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1138 AM CDT SAT JUN 11 2011
   
   VALID 111630Z - 121200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT FOR
   THE HIGH PLAINS INTO OK/KS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON FOR CENTRAL/ERN
   PA SWD INTO VA...
   
   ...HIGH PLAINS THIS AFTERNOON INTO TONIGHT...
   A SERIES OF MIDLEVEL SHORTWAVE TROUGHS WILL EJECT NEWD OVER THE HIGH
   PLAINS FROM THE MEAN TROUGH OVER THE GREAT BASIN...WITH DOWNSTREAM
   LEE CYCLOGENESIS ALREADY UNDERWAY ACROSS ERN WY/CO.  EMBEDDED SPEED
   MAXIMA ARE EXPECTED TO APPROACH THE WY/MT/SD BORDER REGION THIS
   AFTERNOON...AS WELL AS SE CO/SW KS.  THESE SPEED MAXIMA WILL COMBINE
   WITH DAYTIME HEATING AND A POST-FRONTAL UPSLOPE REGIME TO SUPPORT
   SCATTERED AFTERNOON THUNDERSTORM DEVELOPMENT ACROSS THE HIGH PLAINS.
   
   
   THE RICHEST BOUNDARY LAYER MOISTURE IS CONFINED TO THE FRONT ACROSS
   OK...WITH MID-UPPER 50S DEWPOINTS EXPECTED THIS AFTERNOON ACROSS SE
   CO/SW KS/TX PANHANDLE...AND UPPER 40S TO LOWER 50S FROM NE CO TO THE
   NRN HIGH PLAINS.  THE COMBINATION OF LOW-LEVEL MOISTURE/SURFACE
   HEATING AND UPSTREAM MIDLEVEL LAPSE RATES AOA 8 C/KM WILL RESULT IN
   MLCAPE VALUES NEAR 1500 J/KG ACROSS SE CO/SW KS/TX PANHANDLE WHERE
   TEMPERATURES WILL WARM WELL INTO THE 80S...AND NEAR 1000 J/KG WITH
   COOLER SURFACE TEMPERATURES FROM NE CO NWD INTO THE NRN HIGH PLAINS.
    MEANWHILE...EFFECTIVE BULK SHEAR AOA 40 KT WILL BE SUFFICIENT FOR
   SUPERCELLS...WHILE LOW-LEVEL HODOGRAPH CURVATURE/SRH WILL FAVOR
   CYCLONIC STORMS.
   
   THE STEEP LAPSE RATES AND SUPERCELL WIND PROFILES SUGGEST THAT LARGE
   HAIL WILL BE THE MAIN SEVERE THREAT LATER THIS AFTERNOON...WHILE THE
   RISK FOR DAMAGING WINDS WILL INCREASE SOME THIS EVENING WITH STORM
   MERGERS AND COLD POOL GROWTH.  THE TORNADO RISK IS LESS CERTAIN
   GIVEN RELATIVELY LARGE TEMPERATURE-DEWPOINT SPREADS AOA 30 F IN THE
   CORRIDOR OF STRONGEST INSTABILITY ACROSS SE CO/SW KS/TX AND OK
   PANHANDLES.  STILL...A COUPLE OF TORNADOES WILL BE POSSIBLE GIVEN
   THE EXPECTATION OF DISCRETE SUPERCELLS FOR A FEW HOURS AND AN
   INCREASE IN LOW-LEVEL SHEAR THIS EVENING.  FARTHER N INTO SE MT/NE
   WY/WRN SD...A COOLER BOUNDARY LAYER WILL RESULT IN LOWER
   TEMPERATURE-DEWPOINT SPREADS AND ACCORDINGLY WEAKER INSTABILITY. 
   HERE...THERE WILL ALSO BE A RISK FOR A COUPLE OF TORNADOES BEFORE
   UPSCALE GROWTH OF INITIALLY DISCRETE STORMS INTO ONE OR MORE
   CLUSTERS THIS EVENING.
   
   OVERNIGHT...EXPECT THE CONVECTION TO CONTINUE EWD AS AN MCS ALONG
   THE FRONT/INSTABILITY CORRIDOR NEAR THE OK/KS BORDER...SUPPORTED BY
   WAA WITH THE LLJ.  DAMAGING WINDS AND LARGE HAIL WILL BE THE PRIMARY
   SEVERE THREATS.  
   
   ...PA/MD/VA THIS AFTERNOON...
   A REMNANT COLD POOL AND MCV ASSOCIATED WITH OVERNIGHT CONVECTION
   WILL CONTINUE GENERALLY EWD TOWARD CENTRAL PA/NRN VA THIS AFTERNOON.
   STRONG SURFACE HEATING IN ADVANCE OF THE COLD POOL WILL RESULT IN
   MODERATE INSTABILITY THIS AFTERNOON /MLCAPE VALUES APPROACHING 1500
   J PER KG/...AND WEAKENING CONVECTIVE INHIBITION.  DEEP-LAYER
   VERTICAL SHEAR WILL REMAIN RATHER WEAK...WITH ONLY SOME MODEST
   ENHANCEMENT OF LOW-LEVEL SHEAR ALONG THE WARM FRONT INTO ERN PA. 
   THUS...EXPECT A FEW DAMAGING GUSTS AND MARGINALLY SEVERE HAIL TO BE
   THE PRIMARY SEVERE THREATS THIS AFTERNOON.
   
   ..THOMPSON/JIRAK.. 06/11/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z