ZCZC SPCSWODY1 ALL
ACUS01 KWNS 210551
SPC AC 210550

STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK 
DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS.

VALID 211200Z - 221200Z

NO SVR TSTM AREAS FCST.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 WNW CAE AGS MCN
0A8 30 W TCL CBM TUP 40 SE MKL 30 SE BNA TYS AVL SPA 35 WNW CAE.

--- SYNOPSIS ---
MIDDLE-UPPER LEVEL PATTERN WILL FEATURE BROADLY CYCLONIC FLOW
ACROSS NRN ROCKIES AND GREAT LAKES -- W AND SW OF ERN CANADA
LONGWAVE TROUGH -- THEN BECOMING MORE ZONAL ACROSS E COAST.  W
COAST LONGWAVE RIDGE WILL BE BREACHED BY SEVERAL SHORTWAVE
TROUGHS... FIRST OF WHICH IS NOW MOVING EWD ACROSS AZ/SONORAN
DESERTS.  THIS PERTURBATION SHOULD ACCELERATE EWD INTO CONFLUENT
FLOW ALOFT ACROSS SRN PLAINS THIS AFTERNOON...REACHING MS/AL BY END
OF PERIOD IN CONSIDERABLY DEAMPLIFIED STATE.  UPSTREAM TROUGH --
NOW EVIDENT IN MOISTURE CHANNEL IMAGERY AND MID/UPPER LEVEL
ISALLOHYPSIC ANALYSES OFFSHORE FROM CA/ORE COAST -- WILL MAKE
LANDFALL AROUND 21/12Z OVER NRN CA AND MOVE ESEWD ACROSS 4-CORNERS
REGION BY WND OF PERIOD.  ANOTHER UPSTREAM TROUGH -- WITH
ASSOCIATED VORTICITY MAX EVIDENT INVOF 35N155W...WILL APPROACH
COAST NEAR END OF PERIOD BUT SHOULD NOT MOVE ONSHORE UNTIL DAY-2. 
SURFACE COLD FRONT...NOW ANALYZED FROM INVOF TN/KY BORDER WWD
ACROSS OK/NRN TX PANHANDLES...SHOULD MOVE SWD TO NEAR SRN GA AND
MID/UPPER TX COAST BY 22/12Z.

--- SERN CONUS ---
ISOLATED TO WIDELY SCATTERED TSTMS POSSIBLE BY 22/06Z-22/12Z TIME
WINDOW...OVER SRN APPALACHIANS/PIEDMONT REGION BY END OF PERIOD.  
PRIND NARROW PLUME OF MODIFIED AND MARGINALLY MOIST GULF AIR IN LOW
LEVELS WILL BECOME JUXTAPOSED WITH SMALL SWATH OF LARGE SCALE MID-
UPPER LEVEL ASCENT...JUST AHEAD OF TROUGH NOW OVER SWRN STATES. 
RESULTANT LOW LEVEL WARMING/NEAR SATURATION AND MIDLEVEL COOLING IN
FORECAST SOUNDINGS YIELDS UNINHIBITED/ELEVATED MUCAPE IN 50-200
J/KG RANGE.  

--- SWRN CONUS ---
VERY BRIEF/ISOLATED TSTMS MAY OCCUR NEAR BEGINNING OF PERIOD OVER
SRN NM -- IN REGIME OF MARGINAL LOW-MIDLEVEL MOISTURE AND WEAKENING
LARGE SCALE ASCENT AHEAD OF CURRENT AZ TROUGH.  CONVECTIVE
POTENTIAL ASSOCIATED WITH THIS SYSTEM WILL BE DECREASING THROUGHOUT
THIS MORNING.  EXPECT COVERAGE OF TSTMS TO BE TOO LOW BY 21/12Z TO
WARRANT GEN THUNDER FCST. 

--- W COAST ---
PRIND MIDLEVEL DESTABILIZATION WITH TROUGH NOW JUST OFFSHORE WILL
BE INSUFFICIENT TO OVERCOME LOW LEVEL STABILITY AND YIELD THREAT OF
TSTM AREAS.  ISOLATED THUNDER MAY BE POSSIBLE NEAR END OF PERIOD IN
PLUME OF MOIST ADVECTION AND WAA...AHEAD OF MUCH STRONGER TROUGH
FARTHER OFFSHORE.  HOWEVER...COVERAGE SHOULD BE TOO SCANT TO
WARRANT TSTM OUTLOOK FOR THAT REGIME AS WELL. 

..EDWARDS.. 01/21/03

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