SPC AC 211236
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0636 AM CST SUN DEC 21 2003
   
   VALID 211300Z - 221200Z
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 55 S FLG 30 NNE IGM
   30 ESE TPH 55 WNW ELY 30 W PUC 30 E GJT 35 WNW COS LAA 25 SSW EHA 50
   SW AMA 35 NE 4CR 70 E SOW 55 S FLG.
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...SYNOPSIS...
   MID AND UPPER LEVEL FLOW PATTERN WILL AMPLIFY ACROSS THE WEST THIS
   PERIOD AS A STRONG SHORT WAVE TROUGH DIGS ESEWD ACROSS THE FOUR
   CORNERS AREA. A NRN STREAM TROUGH WILL ALSO DIG ACROSS THE NRN
   PLAINS/UPPER MS VALLEY WHILE MID LEVEL HEIGHTS CONTINUE TO RISE OVER
   THE MID ATLANTIC AND NORTHEAST. AT THE SURFACE...LEE-SIDE TROUGH AND
   DOWNSLOPE WARMING WERE ALREADY WELL ESTABLISHED OVER THE HIGH PLAINS
   AHEAD OF THE WRN TROUGH. WITH THE APPROACH OF THE UPPER SYSTEM...LOW
   PRESSURE WILL BECOME BETTER DEFINED FROM SERN CO INTO THE TX/OK
   PNHDLS. MEANWHILE...COLD ANTICYCLONE DOMINATING THE LOWER MS VALLEY
   AND SOUTHEAST WILL SLOWLY EDGE EWD WITH TIME AND ALLOW MARGINAL LOW
   LEVEL MOISTURE RETURN TO COMMENCE ALONG ITS WRN FLANK...ACROSS THE
   TX GULF COAST...BY EARLY MONDAY.
   
   ...FOUR CORNERS TO SRN HIGH PLAINS...
   DESPITE RESPECTABLE SATELLITE APPEARANCE AND LARGE SCALE
   CYCLONICALLY CURVED PRECIPITATION BANDS ACCOMPANYING THE STRONG
   UPPER TROUGH ACROSS THE WEST OVER THE PAST 12-18 HOURS...THIS SYSTEM
   HAS BEEN AN UNDERPERFORMER WITH RESPECT TO CG LIGHTNING ACTIVITY.
   HOWEVER...SHORT-TERM MODELS AND LATEST LIGHTNING DETECTION DATA
   SUGGEST THAT THIS MAY CHANGE OVER THE NEXT SEVERAL HOURS AS 60-90M
   MID LEVEL HEIGHT FALLS SPREAD ACROSS THE FOUR CORNERS AREA...AND
   THEN TO ERN NM THROUGH MONDAY MORNING. MARGINAL INSTABILITY
   INDICATED IN LATEST ETA POINT FCST SOUNDINGS APPEARS TO BE VERIFIED
   BY FLG AND DRA SOUNDINGS THIS MORNING WITH ONLY WEAK CONVECTIVE
   INSTABILITY...LI AROUND 0C...SITUATED AHEAD OF THE IMPULSE CROSSING
   NV AT THIS TIME. LIFT AND MOISTENING ACROSS THE REGION...IN
   CONJUNCTION WITH OROGRAPHIC ASCENT...MAY BE SUFFICIENT FOR A FEW
   WIDELY SCATTERED TSTMS ACROSS THE REGION THROUGH TONIGHT.
   
   STRONG LOW THROUGH MID LEVEL FRONTOGENESIS ASSOCIATED WITH THE
   DEVELOPING LEE-SIDE CYCLONE OVER THE SRN HIGH PLAINS THROUGH EARLY
   MONDAY MAY ALSO FAVOR A FEW ELEVATED TSTMS AS FAR EAST AS SERN
   CO...WRN OK/TX PNHDLS BY LATE IN THE PERIOD.
   
   ..CARBIN/CROSBIE.. 12/21/2003
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 1630Z