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 291221
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0721 AM CDT SAT OCT 29 2011
   
   VALID 291300Z - 301200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...SYNOPSIS AND DISCUSSION...
   
   AN INTENSE VORTICITY MAXIMUM AND ATTENDANT MIDLEVEL JET STREAK OVER
   THE OH/TN VALLEYS WILL LIFT NEWD THROUGH THE MID ATLANTIC STATES
   TODAY...SUBSEQUENTLY CONTRIBUTING TO THE FORMATION OF A DEEP-LAYER
   CYCLONE OVER NEW ENGLAND TONIGHT.  MEANWHILE...AN UPSTREAM SHORTWAVE
   TROUGH OVER THE NRN INTERMOUNTAIN REGION IS FORECAST TO AMPLIFY
   WHILE TRANSLATING SEWD INTO THE NRN PLAINS AND UPPER MS VALLEY.  IN
   THE LOW LEVELS...INCREASING LARGE-SCALE FORCING FOR ASCENT ATTENDANT
   TO THE FORMER VORTICITY MAXIMUM WILL HASTEN CYCLOGENESIS OFF THE MID
   ATLANTIC COAST TODAY WITH THE CYCLONE DEVELOPING TO OFF THE ME COAST
   BY 30/12Z.  A TRAILING COLD FRONT CURRENTLY ACCELERATING SEWD
   THROUGH NRN FL IS EXPECTED TO PROGRESS THROUGH THE REMAINDER OF THE
   STATE BY THIS EVENING.
   
   THE COUPLING OF LOW-LEVEL WAA AND DCVA AHEAD OF NEGATIVELY TILTED
   MIDLEVEL TROUGH WILL ENHANCE DEEP-LAYER ASCENT ACROSS THE MID
   ATLANTIC STATES TODAY...AND INTO CNTRL/SRN NEW ENGLAND TONIGHT. 
   THIS FORCING WILL ALIGN WITH A SATURATED AND WEAKLY BUOYANT
   ENVIRONMENT TO SUPPORT BURSTS OF LIGHTNING ACTIVITY FOR PARCELS
   BASED IN THE 850-700 MB LAYER.
   
   OVER FL...THE SEWD-MOVING COLD FRONT WILL SERVE AS THE FOCUS FOR
   DIURNALLY ENHANCED TSTMS THIS AFTERNOON WITHIN A VERY MOIST WARM
   SECTOR WITH BOUNDARY LAYER DEWPOINTS IN THE 70S AND PW VALUES OF
   AROUND TWO INCHES.  FORECAST SOUNDINGS EXHIBIT POOR LAPSE
   RATES...WHICH WHEN COUPLED WITH RATHER WEAK VERTICAL SHEAR...WILL
   PRECLUDE ORGANIZED SEVERE STORM DEVELOPMENT.
   
   OVER THE GREAT LAKES...FORCING FOR ASCENT ASSOCIATED WITH MIDLEVEL
   VORTICITY MAXIMUM TRANSLATING ESEWD ACROSS THE REGION WILL ACT ON A
   WEAKLY UNSTABLE ENVIRONMENT INVOF THE LAKES TO SUPPORT SPORADIC
   LIGHTNING ACTIVITY TODAY INTO THIS EVENING.
   
   ..MEAD/HURLBUT.. 10/29/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z