STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK
DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS.
VALID 061300Z - 071200Z
THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
15 NNW MGM LGC 35 NNW AGS CAE 40 S CAE 50 NW SAV 70 ESE MCN
55 NW CEW 35 SW SEM 15 NNW MGM.
GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 ESE BPT 30 SE ORF
...CONT... 30 SE JAX 20 W CTY.
--- SYNOPSIS ---
MIDDLE-UPPER LEVEL PATTERN WILL DEAMPLIFY CROSS MOST OF CONUS THIS
PERIOD. THIS WILL RESULT IN NEARLY ZONAL NRN STREAM FROM PACIFIC
NW ACROSS GREAT LAKES...AND WSWLY SRN STREAM CONTAINING RELATIVELY
LOW-AMPLITUDE PERTURBATIONS. POSITIVELY TILTED SHORTWAVE TROUGH --
NOW EVIDENT IN MOISTURE CHANNEL IMAGERY FROM SRN PLAINS TO LOWER OH
VALLEY -- IS FORECAST TO WEAKEN AND MOVE EWD WITH FURTHER
STRETCHING OF MIDLEVEL VORTICITY PATTERN. STRONGEST PORTION OF
TROUGH SHOULD REACH CAROLINAS BY END OF PERIOD. MEANWHILE...
SURFACE FRONTAL ZONE -- NOW OVER SRN APPALACHIANS SWWD OVER NWRN
GULF -- SHOULD MOVE EWD OFF MOST OF ATLANTIC COAST N OF FL BY
07/12Z. TRAILING PORTION OF FRONT BY THEN SHOULD EXTEND FROM NRN
FL WSWWD TO OFFSHORE MS RIVER MOUTH...THEN SWWD OVER E-CENTRAL MEX.
--- SERN CONUS ---
REF WW 31 AND ASSOCIATED SPC MESOSCALE DISCUSSIONS FOR NOWCAST
GUIDANCE REGARDING POTENTIALLY DAMAGING TSTMS NOW MOVING ACROSS
PORTIONS ERN AL AND GA. FAVORABLY MOIST/UNSTABLE LOW LEVEL AIR
MASS WILL REMAIN IN PLACE SE OF FRONT THROUGHOUT DAY ACROSS SERN
CONUS...ALONG WITH STRONG DEEP-LAYER VERTICAL SHEAR PROFILES AND
UNIDIRECTIONAL VERTICAL PROFILES SUPPORTING DAMAGING CONVECTIVE
GUSTS. HOWEVER WE DO EXPECT CONVERGENCE AND OVERALL SEVERE
POTENTIAL TO DIMINISH FROM LATE MORNING ONWARD...AS STRONGEST
ISALLOBARIC FORCING MOVES AWAY FROM REGION...VEERING AND WEAKENING
BOUNDARY LAYER FLOW. FRONT ALSO WILL MOVE SEWD BENEATH WARMER
MIDLEVEL TEMPERATURES AND REDUCED LAPSE RATES ALOFT PER 12Z WARM-
SECTOR RAOBS.
ADDITIONAL CONVECTION MAY DEVELOP N OF SURFACE FRONT TONIGHT -- AS
LOW LEVEL MOISTENING/WAA ACT TO MARGINALLY DESTABILIZE AIR MASS
ABOVE RELATIVELY STABLE BOUNDARY LAYER. ELEVATED MUCAPE 100-300
J/KG POSSIBLE...WITH LAPSE RATES TOO WEAK TO FAVOR ORGANIZED
SEVERE.
..EDWARDS.. 03/06/03
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 1630Z
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