MESOSCALE DISCUSSION 2604
   NWS STORM PREDICTION CENTER NORMAN OK
   1155 AM CST SAT DEC 31 2005
   
   AREAS AFFECTED...SACRAMENTO VALLEY
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 311755Z - 312000Z
   
   ...LOW TOPPED SUPERCELLS MAY DEVELOP ACROSS THE SACRAMENTO VALLEY...
   
   
   LEADING EDGE OF STRONGER CVA IS SPREADING ACROSS THE COASTAL RANGE
   TOWARD THE SACRAMENTO VALLEY LATE THIS MORNING.  MUCH DRIER MID
   LEVELS AND PARTIAL CLEARING ACROSS THE VALLEY WILL ALLOW FOR SOME
   HEATING OVER THE NEXT FEW HOURS..ALTHOUGH SFC TEMPS MAY STRUGGLE TO
   REACH THE LOWER 60S.  UPSTREAM...LATEST DIAGNOSTIC DATA SUGGESTS
   STEEPER LOW-MID LEVEL LAPSE RATES...7C/KM...AND 3KM CAPE...IN EXCESS
   OF 100J/KG...WILL SPREAD INTO THE VALLEY ENHANCING THE PROSPECT FOR
   ROBUST CONVECTION.  ADDITIONALLY...BACKED VALLEY FLOW SHOULD PROVE
   BENEFICIAL FOR SUSTAINING LOW-TOPPED CONVECTION...POSSIBLY AIDING
   STORM ROTATION AND SUPERCELL CHARACTERISTICS.  HAIL IS THE MOST
   LIKELY SEVERE THREAT WITH THIS ACTIVITY...ALTHOUGH A BRIEF TORNADO
   IS ALSO POSSIBLE.
   
   ..DARROW.. 12/31/2005
   
   
   ATTN...WFO...STO...MTR...
   
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