SPC AC 080603
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1203 AM CST TUE MAR 08 2011
VALID 091200Z - 101200Z
...THERE IS A SLGT RISK OF SVR TSTMS ALONG THE CNTRL/ERN GULF
COASTAL AREA...
...SYNOPSIS...
A LEAD UPPER IMPULSE OVER THE FOUR CORNERS REGION WILL DIG INTO THE
SRN PLAINS EARLY TODAY...THEN TURN ENE INTO MIDWEST AND GREAT LAKES
REGION BY WEDNESDAY MORNING. A SECONDARY IMPULSE...NOW OVER THE N
PACIFIC BASIN...IS EXPECTED TO PROPAGATE SEWD IN WAKE OF THIS
SYSTEM...REINFORCING THE LARGER-SCALE TROUGH OVER THE OH/TN VLYS BY
WEDNESDAY NIGHT.
...OH/TN VLYS TO THE CNTRL/ERN GULF COAST AND SERN STATES...
STRONG SLY LOW-LEVEL FLOW TIED TO THE LEAD IMPULSE WILL TRANSPORT
MODIFIED CONTINENTAL POLAR AIR MASS NWD THROUGH THE GULF COASTAL
STATES TO THE MIDWEST TUESDAY AND WEDNESDAY. PREEXISTING COLD/DRY
CONTINENTAL AIR MASS WILL RESULT IN A CONSIDERABLE AMOUNT OF
ISENTROPIC LIFT AND WIDESPREAD ELEVATED SHOWERS/TSTMS WILL BE COMMON
FROM THE MID/LOWER OH VALLEY SOUTH TO THE GULF COAST AT THE START OF
THE PERIOD /WEDNESDAY MORNING/. AS A RESULT...MOST UNSTABLE
BOUNDARY LAYER/EFFECTIVE WARM FRONT WILL PROBABLY BE RELEGATED TO
ERN LA...FAR SRN SECTIONS OF MS/AL AND WRN FL PANHANDLE ON
WEDNESDAY.
SRN AND WRN SECTIONS OF THE ELEVATED BANDS OF STORMS OVER THE LOWER
MS VALLEY WILL LIKELY ROOT INTO A DEEPENING MOIST BOUNDARY LAYER
ALONG/S OF THE WARM FRONT OVERNIGHT TUESDAY. THE MIXED QLCS/MCS
MODES WILL POSE DAMAGING WIND...BRIEF TORNADO AND HAIL THREATS
AMIDST MLCAPES OF 500-1000 J PER KG AND WLY DEEP-LAYER SHEAR OF 50
KTS. STORMS WILL ENCOUNTER A MORE STABLE ENVIRONMENT FARTHER NORTH
AND EAST DURING THE MORNING AND THE STRONGER STORMS SHOULD EVOLVE
ESE WITHIN 100 OR SO MILES FROM THE GULF COAST IN SRN MS/AL AND
PERHAPS THE WRN FL PANHANDLE DURING THE AFTERNOON.
MODELS HAVE CONSIDERABLY REDUCED THE THREAT OF DEVELOPING STORMS IN
WAKE OF THE EARLY DAY ACTIVITY AS THE COLD FRONT LAGS IN THE MIDWEST
AND MS/TN VALLEYS. FURTHERMORE...GUIDANCE HAS TRENDED LESS
UNSTABLE...PARTICULARLY IN THE MIDWEST/OH VLY. HOWEVER...AS SRN
FRINGE OF THE LEAD IMPULSE GRAZES THE MIDWEST/OH VLY...BANDS OF
CONVECTION/POSSIBLE TSTMS MAY DEVELOP IN SRN IND AND BACKBUILD
TOWARD THE LOWER TN VLY WEDNESDAY AFTERNOON. SHOULD A STORM BECOME
SUSTAINED...AMPLE VERTICAL SHEAR WILL EXIST FOR AN ORGANIZED STORM
CAPABLE OF PRIMARILY DAMAGING WIND GUSTS AND LARGE HAIL.
MOST OF THE RENEWED AFTERNOON ACTIVITY WILL DIMINISH DURING THE
EVENING AND WITH EWD EXTENT...BEFORE REACHING THE KY COALFIELDS AND
THE CUMBERLAND PLATEAU/SRN APPALACHIANS. THE ONLY EXCEPTION TO THIS
WILL BE THE POSSIBLE REGENERATION/STRENGTHENING OF STORMS OVER SRN
GA AND THE PIEDMONT/COASTAL PLAINS OF SC/NC VERY LATE IN THE PERIOD.
THIS WILL BE IN RESPONSE TO THE APPROACHING SECONDARY IMPULSE AND
INFLUX OF WRN ATLANTIC MOISTURE NWD AHEAD OF THE COLD FRONT.
ISOLATED STORMS MAY PRODUCE A DAMAGING WIND GUST OR BRIEF TORNADO
OWING TO AMPLE LOW AND DEEP-LAYER SHEAR.
..RACY.. 03/08/2011
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
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