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 090024
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0724 PM CDT SUN MAY 08 2011
   
   VALID 090100Z - 091200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN PLAINS
   AND MID-MO VALLEY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
   PLAINS...
   
   ...NRN PLAINS/MID-MO VALLEY...
   THE LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL RIDGE OVER THE
   MID TO UPPER MS VALLEY WITH SOUTHWEST FLOW IN PLACE FROM THE CNTRL
   HIGH PLAINS NEWD INTO THE NRN PLAINS. A NARROW AXIS OF STRONG TO
   EXTREME INSTABILITY EXISTS FROM ERN NEB NNWWD INTO CNTRL SD WHERE
   SCATTERED THUNDERSTORM INITIATION IS EXPECTED OVER THE NEXT FEW
   HOURS. MESOANALYSIS CURRENTLY ESTIMATES MLCAPE VALUES TO BE IN THE
   3000 TO 5000 J/KG RANGE AND THIS SHOULD HELP STORMS TO RAPIDLY
   BECOME SEVERE AS STORM COVERAGE INCREASES THIS EVENING. THE
   INSTABILITY COMBINED WITH VERY STEEP MID-LEVEL LAPSE RATES OF 8.0 TO
   9.0 C/KM ALONG WITH SUBSTANTIAL DIRECTIONAL SHEAR SHOULD RESULT IN
   SUPERCELL DEVELOPMENT WITH A THREAT FOR LARGE HAIL. THE MORE
   DOMINANT SUPERCELLS MAY HAVE AN ISOLATED TORNADO THREAT AND MAY
   PRODUCE ISOLATED VERY LARGE HAIL OF GREATER THAN 2 INCHES IN
   DIAMETER. THE GREATEST SEVERE THREAT SHOULD EXIST THIS EVENING AS
   THE STORMS DEVELOP ALONG THE AXIS OF STRONGEST INSTABILITY BUT THE
   SEVERE THREAT SHOULD CONTINUE THROUGH MUCH OF THE OVERNIGHT PERIOD
   AS A LOW-LEVEL JET STRENGTHENS ACROSS THE REGION.
   
   ...SRN PLAINS...
   SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE ONGOING ALONG AN AXIS
   OF STRONG INSTABILITY FROM CNTRL OK SSWWD INTO NORTH TX. THE STORMS
   ARE BEING SUPPORTED BY LARGE-SCALE ASCENT ASSOCIATED WITH A
   SHORTWAVE TROUGH EVIDENT ON WATER VAPOR IMAGERY...CURRENTLY MOVING
   EWD TROUGH WEST TX. THIS CONVECTION SHOULD BE SUSTAINED FOR A FEW
   MORE HOURS AS THE STORMS MOVE EWD INTO INCREASING INSTABILITY.
   MLCAPE VALUES OF 2500 TO 3500 J/KG AND VERY STEEP MID-LEVEL LAPSE
   RATES ALONG WITH 30 TO 40 KT OF DEEP LAYER SHEAR SHOULD RESULT IN A
   THREAT FOR ISOLATED LARGE HAIL. A WIND DAMAGE THREAT MAY ALSO
   ACCOMPANY THE MORE INTENSE CELLS DUE TO THE RELATIVELY LARGE
   TEMP-DEWPOINT SPREADS.
   
   ...SRN APPALACHIAN MTNS/CAROLINAS...
   ISOLATED THUNDERSTORMS ARE CURRENTLY ONGOING IN ERN TN AND WRN SC
   LOCATED ALONG THE NERN EDGE OF MODERATE INSTABILITY. THIS CONVECTION
   IS LOCATED IN NORTHWEST FLOW ALOFT WITH ABOUT 40 KT OF DEEP LAYER
   SHEAR ESTIMATED BY MESOSCALE ANALYSIS. THIS SHOULD BE ENOUGH FOR A
   MARGINAL WIND DAMAGE THREAT BUT THE THREAT SHOULD DIMINISH QUICKLY
   AS SFC TEMPS BEGIN TO COOL OFF LATER THIS EVENING.
   
   ..BROYLES.. 05/09/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z