SWODY2
SPC AC 241725
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1125 AM CST WED NOV 24 2010
VALID 251200Z - 261200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
PRINCIPAL UPPER AIR FEATURE WILL REMAIN STG CYCLONE NOW EVIDENT IN
MOISTURE CHANNEL IMAGERY OVER MT...AND FCST TO MOVE FROM ERN ND
ACROSS NRN MN TO LS THROUGH DAY-2. POSITIVELY-TILTED/MID-UPPER
TROUGH WILL TRAIL SWWD FROM LOW...POSITIONED AT 26/00Z FROM MN/WI
BORDER AREA SWWD ACROSS IA...S-CENTRAL KS...TX PANHANDLE AND SWRN
NM.
ASSOCIATED SFC ARCTIC FRONT -- ANALYZED AT 24/16Z FROM ERN NEB SWWD
OVER WRN KS AND ERN CO -- IS EXPECTED TO SURGE SEWD OVER CENTRAL/SRN
HIGH PLAINS AND EWD ACROSS MID-UPPER MS VALLEY BY EARLY IN PERIOD.
BY 26/00Z...FRONT SHOULD EXTEND FROM OCCLUSION TRIPLE POINT OVER OH
SWWD ACROSS WRN TN...NRN MS AND TX GULF COASTAL PLAIN...THEN BY
26/12Z...MOVING ACROSS INLAND MID-ATLANTIC...CENTRAL/SRN
APPALACHIANS...TO NEAR MS RIVER MOUTH AND ACROSS NWRN GULF.
MEANWHILE...SYNOPTIC WARM FRONT WILL SHIFT NEWD FROM CURRENT
POSITION OVER SRN/WRN OZARKS...REACHING PORTIONS INDIANA/OH AROUND
BEGINNING OF PERIOD AND CROSSING PORTIONS PA/NJ BY 26/12Z. WARM
FRONT WILL FAR OUTRUN HIGH-THETAE SFC AIR...WHICH SHOULD REMAIN
FARTHER SW ACROSS LOWER MS VALLEY AND GULF COAST REGIONS.
...LOWER MS VALLEY TO TX COAST...
EARLY IN PERIOD...BAND OF CONVECTION WITH EMBEDDED TSTMS SHOULD
CARRY OVER FROM END OF DAY-1 INVOF SFC COLD FRONT...FROM LOWER OH
VALLEY SWWD ACROSS ERN/SRN OZARKS TO SE OK AND PORTIONS N-CENTRAL/NE
TX. ACTIVITY COULD BACKBUILD THROUGH N-CENTRAL TX AS FAR SW AS
CENTRAL TX HILL COUNTRY...WHERE POTENTIAL WILL BE LIMITED BY
COMBINATION OF CAPPING IN 700-850 MB LAYER AND MORE MEAGER
PREFRONTAL MOISTURE IN LOW LEVELS. OVER ARKLATEX REGION AND SWD TO
MID-UPPER TX COAST...WARM-SECTOR SFC DEW POINTS MID-UPPER 60S F WILL
BE COMMON...WITH SOME 70S OVER E TX. SFC-BASED EFFECTIVE INFLOW
PARCELS AND WEAK CAPPING ARE EVIDENT IN 25/12Z FCST SOUNDINGS FROM N
TX ACROSS SE OK AND AR...WITH PEAK MLCAPE IN 500-800 J/KG RANGE OVER
NE TX/SE OK...DIMINISHING NEWD ACROSS AR AND SWWD OVER N TX. STG
LOW-LEVEL SHEAR AND ENLARGED HODOGRAPHS ALSO ARE FCST EARLY
DAY-2...ALONG WITH 35-50 KT EFFECTIVE SHEAR...ALTHOUGH LINEAR STORM
ORGANIZATION AND WEAK MORNING STABLE LAYER NEAR SFC BY THIS TIME
SHOULD KEEP SVR GUST POTENTIAL MRGL.
THROUGH AFTERNOON...PREFRONTAL SFC AIR MASS FROM E TX ACROSS AR AND
NRN LA WILL REMAIN FAVORABLY MOIST. MEANWHILE DIABATIC HEATING
SHOULD OFFSET WEAK LAPSE RATES ALOFT AND YIELD WELL-MIXED BOUNDARY
LAYER...BOOSTING MLCAPE TO NEAR 1000 J/KG IN SOME LOCALES. MAIN
CONVECTIVE MODE NEAR FRONT WILL REMAIN LINEAR GIVEN PARALLEL NATURE
OF FLOW ALOFT WITH RESPECT TO BOUNDARY...WHOSE MOVEMENT MAY EVEN
YIELD ANAFRONTAL REGIME WHERE FRONTAL CURRENT UNDERCUTS CONVECTION.
WARM SECTOR WILL BE WEAKLY CAPPED...BUT ALSO ONLY WEAKLY
CONFLUENT/CONVERGENT BENEATH POOR LAPSE RATES...CASTING UNCERTAINTY
ON INITIATION/COVERAGE OF PREFRONTAL TSTMS. GIVEN THESE
FACTORS...WILL MAINTAIN MRGL SVR PROBABILITIES ATTM.
..EDWARDS.. 11/24/2010
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