Sep 4, 2012 0730 UTC Day 3 Severe Thunderstorm Outlook
Updated: Tue Sep 4 07:33:42 UTC 2012
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20120904 0730 UTC Day 3 Outlook Graphic
Probabilistic Graphic
20120904 0730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
   SPC AC 040731
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0231 AM CDT TUE SEP 04 2012
   
   VALID 061200Z - 071200Z
   
   ...SYNOPSIS...
   A COLD FRONT WILL CONTINUE MOVING ACROSS THE MIDWEST/OH VALLEY AND
   INTO THE NORTHEAST THIS PERIOD...AS SHORT-WAVE TROUGHING SHIFTS
   ACROSS THE AREA IN FAST WLY/CYCLONIC FLOW ALOFT.
   
   MEANWHILE...A SECOND FRONT WILL BEGIN DIVING SEWD ACROSS THE PLAINS
   AS A SHORT-WAVE TROUGH DIGS SEWD ON THE WRN FRINGE OF THE LARGER
   UPPER VORTEX OVER CENTRAL CANADA.  BOTH OF THESE FRONTS WILL FOCUS
   ACTIVE CONVECTION THIS PERIOD.
   
   ...LOWER GREAT LAKES/UPPER OH VALLEYS SWWD INTO TN/KY...
   A COLD FRONT WILL CONTINUE ADVANCING ACROSS THE MIDWEST/OH VALLEY
   THIS PERIOD...REACHING THE LOWER LAKES/UPPER OH VALLEY REGION BY
   LATE AFTERNOON.  AHEAD OF THE FRONT...A DIURNALLY DESTABILIZING
   WARM-SECTOR AIRMASS LIKELY TO SUPPORT AN INCREASE IN
   LIKELY-TO-BE-ONGOING CONVECTION.  
   
   WITH MODERATE FLOW ALOFT EXPECTED ACROSS THE REGION...SOME
   ORGANIZATION OF CONVECTION INTO LINES IS EXPECTED -- WITH ISOLATED
   STRONGER CELLS LIKELY TO BECOME CAPABLE OF LOCALLY GUSTY WINDS AND
   SOME HAIL.  THIS THREAT SHOULD EXTEND INTO EARLY EVENING AS STORMS
   MOVE INTO THE APPALACHIANS...BUT EXPECT CONVECTION TO DIMINISH
   OVERNIGHT AS COOLING/STABILIZATION COMMENCES.
   
   ...KS/OK AND VICINITY...
   WEAK/HIGH-BASED DESTABILIZATION ACROSS THE KS/OK VICINITY IS
   EXPECTED DURING THE AFTERNOON...AHEAD OF THE UPPER SYSTEM DIGGING
   SEWD ACROSS THE NRN HIGH PLAINS.  WITH BROAD/DIFFUSE LOW PRESSURE
   EXPECTED ACROSS THE AREA -- SUPPORTED BY A WEAK LEAD FEATURE ALOFT
   SHIFTING ESEWD OUT OF CO -- ISOLATED/HIGH-BASED SHOWERS AND
   THUNDERSTORMS SHOULD DEVELOP DURING THE AFTERNOON.  AIDED BY 40 KT
   MID-LEVEL WSWLYS ALOFT...A FEW STRONGER STORMS MAY EVOLVE WITH
   TIME...WHICH MAY BECOME CAPABLE OF PRODUCING
   ISOLATED/EVAPORATIVELY-AIDED WIND GUSTS AND/OR MARGINAL HAIL.  
   
   AS THE FRONT DIVES SEWD ACROSS THE PLAINS DURING THE EVENING AND A
   SWLY LOW-LEVEL JET DEVELOPS OVER THE WARM SECTOR...STORMS WILL
   LIKELY CONTINUE OVERNIGHT.  GIVEN THE STRENGTH OF THIS FRONT...A FEW
   STRONGER/LOCALLY SEVERE STORMS WILL LIKELY PERSIST THROUGH THE END
   OF THE PERIOD.  ATTM...WILL INTRODUCE ONLY A BROAD 5% THREAT
   AREA...BUT UPGRADE TO SLIGHT RISK MAY BECOME NECESSARY IN LATER
   FORECASTS.
   
   ..GOSS.. 09/04/2012
   
   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z