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 100557
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1257 AM CDT WED AUG 10 2011
   
   VALID 101200Z - 111200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN KS/ERN OK EWD INTO
   THE SRN APPALACHIANS...
   
   ...SYNOPSIS...
   ONLY MINOR CHANGES EXPECTED IN THE LARGE SCALE UPPER PATTERN THIS
   PERIOD...WITH A FLAT RIDGE OVER THE S CENTRAL AND SWRN STATES...VERY
   WEAK TROUGHING OVER THE NW...AND TROUGHING OVER THE EAST.
   
   AT THE SURFACE...A BAROCLINIC ZONE IS FORECAST TO LIE NNW-SSE ALONG
   THE HIGH PLAINS...AND THEN MORE EWD ACROSS THE SRN PLAINS/MID LOWER
   MS VALLEY AND INTO THE SOUTHEAST.  THIS BOUNDARY WILL COINCIDE WITH
   A ZONE OF CONVECTIVE/LOW-END SEVERE POTENTIAL THROUGH THE PERIOD.
   
   ...SERN KS/ERN OK EWD INTO THE MID MS/TN VALLEYS...
   SOMEWHAT DIFFICULT FORECAST ACROSS THIS REGION IN TERMS OF
   DETAILS...AS WIDESPREAD CONVECTION ONGOING FROM NEB SWD INTO OK WILL
   BE SHIFTING INTO THE SLIGHT RISK AREA EARLY IN THE PERIOD. 
   PRESUMING AMPLE DESTABILIZATION CAN OCCUR AHEAD OF THE LINGERING
   CONVECTION...STORMS SHOULD REINTENSIFY DURING THE AFTERNOON -- AIDED
   BY MODERATE WLY/WNWLY FLOW ALOFT.  
   
   STORMS SHOULD SHIFT EWD/ESEWD WITH TIME...MOVING ACROSS THE
   MID/LOWER MS VALLEY INTO THE TN VALLEY...BEFORE WEAKENING DURING THE
   EVENING INTO THE SRN APPALACHIANS.  IN THE MEAN TIME...THREATS FOR
   HAIL AND LOCALLY DAMAGING WINDS CAN BE EXPECTED ACROSS THE SLIGHT
   RISK AREA.
   
   ...HIGH PLAINS...
   ISOLATED CONVECTIVE DEVELOPMENT IS FORECAST DURING THE EVENING FROM
   SWRN MT SEWD/SWD ALONG THE HIGH PLAINS/FRONT RANGE REGION...AS
   AIRMASS BECOMES MODESTLY UNSTABLE IN CONJUNCTION WITH DAYTIME
   HEATING.  WITH SHEAR SUFFICIENT FOR SOME DEGREE OF ORGANIZATION/WEAK
   ROTATION...EXPECT STRONGER CELLS TO BE CAPABLE OF PRODUCING GUSTY
   WINDS AND HAIL.  ATTM...LIMITED COVERAGE IS ANTICIPATED...WHICH
   PRECLUDES MORE THAN LOW SEVERE PROBABILITIES.
   
   ...THE NORTHEAST/NEW ENGLAND...
   COOL AIR ALOFT ASSOCIATED WITH THE UPPER TROUGH COMBINED WITH
   DAYTIME HEATING WILL YIELD MODEST AFTERNOON DESTABILIZATION...AND
   EVENTUAL DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED
   THUNDERSTORMS.  A FEW OF THE STRONGEST CELLS -- AIDED BY MODERATE
   FLOW ALOFT -- MAY PRODUCE LOCALLY GUSTY WINDS AND HAIL UNTIL STORMS
   WEAKEN DURING THE EVENING.
   
   ..GOSS/GRAMS.. 08/10/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z