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 150559
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1259 AM CDT WED AUG 15 2012
   
   VALID 151200Z - 161200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE N CENTRAL U.S....
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE ERN SEABOARD FROM
   SRN NEW ENGLAND TO SC...
   
   ...SYNOPSIS...
   A POTENT MID-LEVEL SHORT-WAVE TROUGH IS FORECAST TO CONTINUE DIGGING
   QUICKLY ESEWD ACROSS THE CANADIAN PRAIRIE AND ADJACENT N CENTRAL
   U.S. THIS PERIOD.  MEANWHILE FARTHER E...A WEAKER TROUGH IS FORECAST
   TO CROSS THE APPALACHIANS EARLY...CONTINUING EWD AND MOVING OFFSHORE
   LATE.
   
   AT THE SURFACE...A STRONG COLD FRONT -- ASSOCIATED WITH THE N
   CENTRAL U.S. UPPER SYSTEM -- IS FORECAST TO MOVE QUICKLY SEWD ACROSS
   THE NRN PLAINS THROUGH THE DAY...AND IS EXPECTED TO EXTEND FROM THE
   UPPER GREAT LAKES REGION SWWD INTO WRN OK/W TX BY THE END OF THE
   PERIOD.  IN THE EAST...A COLD FRONT IN LEE OF THE APPALACHIANS IS
   PROGGED TO SHIFT SLOWLY EWD THROUGH THE DAY...REMAINING ONSHORE
   THROUGH THE AFTERNOON BUT BEGINNING OFFSHORE PROGRESS BY EVENING. 
   BOTH OF THESE FRONTS WILL FOCUS CONVECTIVE DEVELOPMENT -- AND SOME
   SEVERE POTENTIAL -- THIS PERIOD.
   
   ...N CENTRAL CONUS...
   COOLING ALOFT ATOP A MOISTENING BOUNDARY LAYER WILL LEAD TO MODERATE
   DESTABILIZATION AHEAD OF THE FAST-MOVING COLD FRONT THIS AFTERNOON. 
   AS A RESULT...EXPECT FOCUSED ASCENT ALONG THE FRONT TO DRIVE STORM
   INITIATION IN THE NWRN MN/SERN ND REGION DURING THE MID-AFTERNOON
   HOURS...WITH AT LEAST SCATTERED DEVELOPMENT OCCURRING SWWD ALONG THE
   FRONT THEREAFTER -- POSSIBLY AS FAR SW AS NEB.  
   
   THE GREATEST SEVERE POTENTIAL HOWEVER -- LIKELY IN THE FORM OF
   DAMAGING WINDS ASSOCIATED WITH A WELL-ORGANIZED LINE AND POSSIBLY
   SOME BOWING STRUCTURES -- IS EXPECTED ACROSS A PORTION OF THE ERN
   DAKOTAS BUT PARTICULARLY MN...FROM FROM MID AFTERNOON THROUGH EARLY
   EVENING.  SOME THREAT MAY CONTINUE EWD INTO WRN PORTIONS OF THE
   UPPER GREAT LAKES REGION LATER IN THE EVENING...BUT DIURNAL
   COOLING/STABILIZATION SUGGEST LESSER POTENTIAL THAN EARLIER/FARTHER
   W.
   
   FARTHER SW INTO IA/NEB -- AND POSSIBLY NRN KS/NRN MO AFTER DARK...A
   MORE MULTICELL-TYPE EVENT IS EXPECTED WITH ISOLATED POTENTIAL FOR
   MARGINAL WIND/HAIL.
   
   ...E COAST FROM SRN NEW ENGLAND TO SC...
   STORM DEVELOPMENT IS FORECAST BY EARLY AFTERNOON E OF THE
   APPALACHIANS...WITHIN A MOIST/DESTABILIZING AIRMASS NEAR AND AHEAD
   OF THE SLOWLY ADVANCING COLD FRONT.  GIVEN DEGREE OF DESTABILIZATION
   CURRENTLY ANTICIPATED...SHEAR -- WHILE SOMEWHAT MODEST IN MOST AREAS
   -- WILL BE SUFFICIENT TO SUPPORT MULTICELLS/WEAK SUPERCELLS AND
   ATTENDANT POTENTIAL FOR LOCALLY DAMAGING WINDS AND/OR HAIL.  WHILE A
   FEW STRONGER STORM CLUSTERS COULD SUPPORT LOCALLY GREATER SEVERE
   WEATHER COVERAGE...CONFIDENCE IS NOT HIGH ENOUGH ON WHERE THESE
   GREATER THREAT CORRIDORS MAY EXIST -- THUS PRECLUDING INTRODUCTION
   OF HIGHER PROBABILITIES WITHIN THE SLIGHT RISK AREA.  
   
   THE THREAT SHOULD CONTINUE INTO THE EVENING AS STORMS MOVE ACROSS
   COASTAL REGIONS...BEFORE GRADUALLY SHIFTING OFFSHORE THROUGH LATE
   EVENING.
   
   ..GOSS/HURLBUT.. 08/15/2012
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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