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 211233
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0633 AM CST MON JAN 21 2013
   
   VALID 211300Z - 221200Z
   
   ...NO TSTM AREAS FORECAST...
   
   ...SYNOPSIS/FORECAST...
   A SPRAWLING SFC ANTICYCLONIC AND ASSOCIATED ARCTIC AIR MASS WILL
   EXTEND FROM THE NRN PLAINS TO THE MIDDLE/UPPER MS VALLEY AND EWD TO
   THE ATLANTIC COAST. ATOP THIS COLD AIR MASS...A BELT OF FAST
   MID-LEVEL FLOW WILL LIE WITHIN THE PERIPHERY OF A BROAD CYCLONE
   PROTRUDING S OF THE CANADIAN BORDER. THIS AREA WILL AMPLIFY
   TODAY...AS AN EMBEDDED SHORTWAVE TROUGH IS STEERED THROUGH ITS
   BASE...AND VERY COLD AIR INVADES THE GREAT LAKES REGION AND THE
   NORTHEAST.
   
   CONVECTIVELY ENHANCED SNOW SHOWERS WITHIN A ZONE OF DCVA PRECEDING
   THE SHORTWAVE TROUGH WILL TRACK EWD FROM THE LOWER GREAT LAKES
   REGION TO THE ATLANTIC COAST THROUGH THIS EVENING. HOWEVER...
   LIGHTNING WILL BE UNLIKELY OWING TO VERY MEAGER BUOYANCY PER
   FORECAST SOUNDINGS.
   
   SUCCEEDING THIS ACTIVITY...BANDS OF LAKE EFFECT SNOW WILL EVOLVE
   OVER/DOWNWIND OF INDIVIDUAL GREAT LAKES THROUGH TONIGHT. THIS WILL
   OCCUR AS SENSIBLE HEAT FLUXES ATOP THE RELATIVELY WARMER LAKE WATERS
   YIELD MODESTLY DEEP CONVECTIVE BOUNDARY LAYERS. AN ISOLATED
   LIGHTNING STRIKE OR TWO CANNOT BE RULED OUT WITH THE MOST INTENSE
   SNOW BANDS...ESPECIALLY THOSE RESULTING FROM THE GREATEST OVER-LAKE
   FETCH LENGTHS. HOWEVER...FORECAST SOUNDINGS SUGGEST THAT THE CLOUD
   LAYER MAY BECOME TOO COLD TO SUPPORT ANY APPRECIABLE SUPERCOOLED
   LIQUID WATER CONTENT. THIS SHOULD MITIGATE THE THREAT FOR CHARGE
   SEPARATION SUPPORTING LIGHTNING...THUS PRECLUDING
   GENERAL-THUNDERSTORM DELINEATION.
   
   ELSEWHERE...DRY/STABLE THERMODYNAMIC PROFILES SHOULD PREVENT THE
   DEVELOPMENT OF DEEP...LIGHTNING-PRODUCING CONVECTION.
   
   ..COHEN/EDWARDS.. 01/21/2013
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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