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 071919
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0219 PM CDT WED SEP 07 2011
   
   VALID 072000Z - 081200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN PA AND NJ SWD INTO
   NERN NC...
   
   ...MID ATLANTIC...
   LOWERED SEVERE WIND PROBABILITIES TO AN EXPECTED COVERAGE OF 5% DUE
   TO MARGINAL WIND PROFILES AS WELL AS POOR LAPSE RATES.
   HOWEVER...SLIGHT RISK REMAINS MAINLY FOR THE POSSIBILITY OF A
   TORNADO OR TWO AS A VERY MOIST AIR MASS REMAINS WITH SUFFICIENT LOW
   LEVEL SHEAR.
   
   ...ELSEWHERE...
   ADJUSTED THE 10% GENERAL THUNDERSTORM LINE FARTHER SE ACROSS NM AND
   W TX FOR WEAK MID LEVEL CONVECTION CAPABLE OF PRODUCING ISOLATED
   STRIKES.
   
   ..JEWELL.. 09/07/2011
   
   .PREV DISCUSSION... /ISSUED 1057 AM CDT WED SEP 07 2011/
   
   ...MID ATLANTIC STATES...
   
   UPPER LOW OVER CNTRL KY WILL SLOWLY DRIFT NWD DURING THE D1 PERIOD
   WHILE ASSOCIATED VORTICITY MAXIMUM PIVOTS FROM THE SRN APPALACHIANS
   ACROSS THE PIEDMONT.  IN THE LOW LEVELS...NRN EXTENSION OF
   PRONOUNCED BAROCLINIC ZONE EXTENDING FROM CNTRL NJ SSWWD THROUGH ERN
   VA INTO CNTRL NC WILL ATTEMPT TO PROGRESS NWWD/WWD TODAY...WHILE SRN
   EXTENSION ADVANCES EWD ACROSS ERN NC.
   
   DEEP MERIDIONAL FLOW REGIME IN PLACE ALONG/E OF SURFACE FRONT WILL
   MAINTAIN THE FLUX OF A VERY MOIST AIR MASS /I.E. PW VALUES ABOVE TWO
   INCHES/ OFF THE ATLANTIC.  WHEN COUPLED WITH BREAKS IN THE
   CLOUDS...WARM SECTOR WILL GRADUALLY DESTABILIZE WITH AFTERNOON
   MLCAPE VALUES OF AROUND 1000 J/KG.  LATEST MESOSCALE AND
   CONVECTION-ALLOWING MODEL GUIDANCE REMAIN IN GOOD AGREEMENT IN
   SUGGESTING THAT ONGOING BAND OF TSTMS FROM ERN NC NWD INTO THE
   SUSQUEHANNA RIVER VALLEY WILL PERSIST...LARGELY DRIVEN BY LOW-LEVEL
   CONVERGENCE ALONG/E OF FRONT.
   
   CURRENT VAD DATA ACROSS WARM SECTOR INDICATE LARGELY UNIDIRECTIONAL
   FLOW THROUGH THE TROPOSPHERE WITH MODEST LOW-LEVEL SHEAR.  THOUGH
   SOME SLIGHT STRENGTHENING OF MIDLEVEL WIND FIELD IS FORECAST BY
   AFTERNOON INVOF SURFACE FRONT...OVERALL HODOGRAPH STRUCTURE IS
   EXPECTED TO REMAIN RELATIVELY UNCHANGED.  AS SUCH...EXPECT A
   CONTINUATION OF LINE SEGMENTS WITH SOME POTENTIAL FOR
   EMBEDDED...TRANSIENT CIRCULATIONS.  ISOLATED OCCURRENCES OF DAMAGING
   WINDS AND PERHAPS A TORNADO WILL REMAIN POSSIBLE THROUGH THIS
   AFTERNOON AND EVENING.  THIS SEVERE THREAT SHOULD DIMINISH TONIGHT
   AS THE BOUNDARY LAYER COOLS AND STABILIZES.
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z