ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 310830
   SPC AC 310830
   
   DAY 4-8 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0230 AM CST WED DEC 31 2008
   
   VALID 031200Z - 081200Z
   
   ...DISCUSSION...
   GFS AND ECMWF REMAIN FAIRLY CONSISTENT THROUGH DAY 5 /SUN.
   1-4/...BUT BEGIN DIVERGING DAY 6 -- PARTICULARLY FROM THE LATTER
   HALF OF DAY 6 ONWARD.  THE MODEL DIFFERENCES BETWEEN THE TWO
   DETERMINISTIC MODELS ARE GREATER THAN 24 HOURS AGO...AND LIKEWISE
   MORE SPREAD IS EVIDENT WITHIN THE MOST RECENT NCEP MEDIUM-RANGE
   ENSEMBLE RUN.
   
   A VERY LIMITED SEVERE POTENTIAL IS EVIDENT DAY 4 /SAT. 1-3/ ACROSS
   ERN PORTIONS OF THE SRN PLAINS AND INTO THE LOWER MS VALLEY
   REGION...AS A SURFACE LOW -- AND ASSOCIATED WARM SECTOR -- SHIFTS
   EWD WITH TIME FROM THE CENTRAL HIGH PLAINS INTO TO THE LOWER OH
   VALLEY VICINITY.  
   
   GREATER POTENTIAL THREAT HOWEVER STILL APPEARS POSSIBLE BEGINNING
   LATE DAY 6...AS A STRONGER UPPER TROUGH -- A PIECE OF WHICH IS
   PROGGED TO CROSS NRN MEXICO AND THE SWRN/S CENTRAL CONUS --
   APPROACHES.  WHILE THE GFS IS MUCH FARTHER S WITH THE RESULTING
   SURFACE CYCLOGENESIS THAN PRIOR RUNS...KEEPING THE LOW INVOF THE
   GULF COAST...THE ECMWF -- AND TO A LESSER DEGREE THE MREF --
   CONTINUE TO DEPICT A LOW MOVING NEWD ACROSS THE LOWER MS VALLEY INTO
   THE TN VALLEY/MID-SOUTH REGION.  THOUGH SEVERE POTENTIAL IN THE GFS
   WOULD LIKELY REMAIN CONFINED TO THE GULF COASTAL REGION AT
   BEST...THE ECMWF AND MREF STILL IMPLY A THREAT FOR A FAIRLY
   SUBSTANTIAL SEVERE EVENT FARTHER INLAND ACROSS THE SOUTHEAST QUARTER
   OF THE CONUS FOR DAY 7 /TUE. 1-6/.  DESPITE THE CONTINUED
   POTENTIAL...WILL REFRAIN ONCE AGAIN FROM HIGHLIGHTING A THREAT AREA
   THIS FORECAST...AS MODEL DIFFERENCES STILL CAST DOUBT UPON THE
   OVERALL PREDICTABILITY OF THIS SYSTEM.
   
   ..GOSS.. 12/31/2008

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