Categorical Graphic
Probabilistic 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 311656
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1156 AM CDT THU MAY 31 2012
   
   VALID 011200Z - 021200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE ERN U.S....
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE TX PANHANDLE...
   
   ...ERN U.S...
   
   AN AREA OF STRONG HEIGHT FALLS...ON THE ORDER OF 60-90M...WILL
   OVERSPREAD THE OH VALLEY DURING THE DAY FRIDAY AS SLIGHTLY NEGATIVE
   TILTED UPPER TROUGH AXIS PROGRESSES TO A POSITION FROM LOWER
   MI...ARCING SEWD TO SC BY 02/00Z.  AN EXPANSIVE AREA OF LARGE SCALE
   ASCENT IS EXPECTED TO OVERSPREAD THE REGION AHEAD OF THIS UPPER
   DIFFLUENT TROUGH AND SHOULD PROVE SUPPORTIVE OF WIDESPREAD
   CONVECTION ALONG ADVANCING COLD FRONT AS IT SURGES EWD.
   
   THUNDERSTORMS SHOULD BE ONGOING EARLY IN THE PERIOD ALONG THE COLD
   FRONT FROM OH...SWD INTO NRN GA.  WHILE STRONG SHEAR WILL COINCIDE
   WITH THIS ACTIVITY IN ALL LIKELIHOOD BROKEN LINEAR TSTM SEGMENTS
   SHOULD BE MOSTLY NON-SEVERE...OR PERHAPS MARGINALLY SEVERE AT
   DAYBREAK.  MAIN LIMITING FACTOR FOR SEVERE EARLY IN THE PERIOD WILL
   BE DUE TO MEAGER INSTABILITY.  HOWEVER...BOUNDARY LAYER HEATING
   SHOULD AID IN AIR MASS DESTABILIZATION BY 18Z AND SUFFICIENT
   BUOYANCY WILL DEVELOP FOR ROBUST UPDRAFTS WITHIN AN ENVIRONMENT MORE
   THAN SUFFICIENTLY SHEARED FOR ORGANIZATION.  IN FACT...FORECAST
   SOUNDINGS SUGGEST ROTATING UPDRAFTS/SUPERCELL STRUCTURES ARE
   POSSIBLE.  GIVEN THE AFOREMENTIONED LARGE SCALE SUPPORT...IT APPEARS
   A STRONGLY FORCED SQUALL LINE SHOULD BE NOTED WITH ADVANCING COLD
   FRONT AND GRADUAL INTENSIFICATION IS EXPECTED AS AIR MASS
   DESTABILIZES...PRIMARILY EAST OF THE APPALACHIANS AND WITH TIME
   ACROSS PORTIONS OF PA.  DAMAGING WINDS MAY BE COMMON WITH THE SQUALL
   LINE...ESPECIALLY IF MUCAPE CAN EXCEED 1500 J/KG AS NAM SUGGESTS. 
   AT THIS TIME WILL MAINTAIN 30% SEVERE PROBS TO ACCOUNT FOR THE
   EXPECTED STRONG WINDS WITH THE FRONTAL CONVECTION AND FOR ISOLATED
   TORNADOES THAT COULD BE NOTED IF PRE-FRONTAL DISCRETE SUPERCELLS
   DEVELOP.  HOWEVER...THERE IS SOME CONCERN THAT A MORE WIDESPREAD
   EVENT MAY EVOLVE IF LOW LEVEL LAPSE RATES/INSTABILITY RESPOND PRIOR
   TO FRONTAL PASSAGE AND SEVERE PROBS MAY BE INCREASED TO ACCOUNT FOR
   THIS SCENARIO IN LATER OUTLOOKS.
   
   ...TX PANHANDLE...
   
   STRONG BOUNDARY LAYER HEATING IS EXPECTED BY MID DAY ACROSS THE HIGH
   PLAINS FROM NERN NM INTO THE TX PANHANDLE.  MODELS SUGGEST RAPID SFC
   HEATING WILL CONTRIBUTE TO VERY STEEP LAPSE RATES ALONG BACK SIDE OF
   SFC ANTICYCLONE AND AHEAD OF WEAK LEE CYCLONE.  RESIDUAL LOW LEVEL
   MOISTURE SHOULD PROVE ADEQUATE FOR THUNDERSTORM DEVELOPMENT AS
   SBCAPE VALUES WILL LIKELY APPROACH 2000 J/KG ACROSS THE TX PANHANDLE
   WHERE MID 50S DEW POINTS ARE ABLE TO BE MAINTAINED.  WITH PRONOUNCED
   DIRECTIONAL TURNING THROUGH A DEEP LAYER AND MID LEVEL FLOW ON THE
   ORDER OF 30KT IT WOULD SEEM POSSIBLE THAT SCATTERED SUPERCELLS WILL
   DEVELOP BY 21Z.  SUBSEQUENT SSEWD PROPAGATION IS EXPECTED INTO THE
   EARLY EVENING HOURS AIDED IN PART BY LLJ.  LARGE HAIL IS THE MOST
   LIKELY SEVERE THREAT.
   
   ...DAKOTAS...
   
   HAVE OPTED TO LOWER THE SEVERE PROBS ACROSS PORTIONS OF THE DAKOTAS
   FRIDAY AS LOW LEVEL MOISTURE/INSTABILITY ARE LIKELY FORECAST TOO
   HIGH ACROSS THIS REGION IN LATEST MODEL GUIDANCE.  THERE IS LITTLE
   INDICATION...BASED ON LATEST OBSERVATIONAL DATA...THAT 50S SFC DEW
   POINTS WILL RETURN TO THIS REGION AND BUOYANCY WILL THUS BE LESS
   THAN FORECAST.
   
   ..DARROW.. 05/31/2012
   
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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z