SPC AC 150102
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0802 PM CDT FRI MAR 14 2008
VALID 150100Z - 151200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE SRN PLAINS
INTO THE LOWER MS VALLEY AND SERN U.S....
...ERN OK AND EXTREME NERN TX THROUGH THE LOWER MS VALLEY...
A COLD FRONT EXTENDS FROM THE TN VALLEY REGIONS SWWD AND BECOMES A
QUASISTATIONARY FRONT ACROSS SRN AR...THEN WNWWD TO A SURFACE LOW IN
WRN OK. A DRYLINE EXTENDS FROM S CNTRL OK SWD THROUGH ERN TX. THE
ATMOSPHERE HAS BECOME MODERATELY UNSTABLE IN WARM SECTOR SOUTH OF
THE FRONT FROM SRN AR...NRN LA THROUGH ERN TX WHERE RICHER LOW LEVEL
MOISTURE WITH 50S DEWPOINTS EXISTS IN WARM SECTOR BENEATH STEEP MID
LEVEL LAPSE RATES. TEMPERATURES WARMED INTO THE LOW 80S IN THIS AREA
EARLIER THIS AFTERNOON...AND THE CAP HAS WEAKENED SUFFICIENTLY FOR
ISOLATED CELLS TO BEGIN DEVELOPING FROM EXTREME NW LA INTO SWRN AR.
ACTIVITY IS EXPECTED TO INCREASE IN COVERAGE AND EXPAND NEWD AS THE
LOW LEVEL JET STRENGTHENS DOWNSTREAM FROM OK VORT MAX AND ENHANCES
LIFT ALONG AND NORTH OF THE FRONT. AS THE LOW LEVEL JET STRENGTHENS
AND MID LEVEL SPEED MAX SHIFTS EWD...0-1 KM HODOGRAPH SIZE AND DEEP
SHEAR WILL INCREASE AND SUPPORT SUPERCELLS WITH POTENTIAL FOR LOW
LEVEL MESOCYCLONES. LARGE HAIL AND ISOLATED TORNADOES ARE POSSIBLE
BEFORE THE BOUNDARY LAYER BEGINS TO DECOUPLE LATER THIS EVENING.
FARTHER WEST...HIGH BASED CONVECTION SPREADING EWD OUT OF CNTRL OK
IN ASSOCIATION WITH VORT MAX MAY INTENSIFY AS IT CONTINUES EWD
DURING THE EVENING AND ENCOUNTERS INCREASINGLY MOIST AND UNSTABLE
INFLOW ASSOCIATED WITH DEVELOPING LOW LEVEL JET. DAMAGING WIND GUSTS
AND HAIL WILL BE THE MAIN THREATS. OTHER STORMS WILL LIKELY DEVELOP
WITHIN ZONE OF INCREASING ISENTROPIC ASCENT NORTH OF FRONT ACROSS
CNTRL AND NRN AR INTO PARTS OF NRN MS...AL AND TN LATER TONIGHT AS
THE LOW LEVEL JET STRENGTHENS. PRIMARY THREAT WILL BE ISOLATED LARGE
HAIL...BUT ISOLATED DAMAGING WIND MAY ALSO BE POSSIBLE.
...AL AND GA...
THREAT FOR ISOLATED DAMAGING WIND AND HAIL WILL CONTINUE WITH STORMS
DEVELOPING OVER NERN AL AND PARTS OF GA WITHIN ZONE OF LOW LEVEL
CONVERGENCE ALONG PRE-FRONTAL TROUGH. DEEP LAYER ASCENT ASSOCIATED
WITH SHORTWAVE TROUGH OVER THE TN VALLEY IS SHIFTING EAST OF THIS
REGION. THIS ALONG WITH ONSET OF NOCTURNAL COOLING SUGGEST STORMS
WILL PROBABLY GRADUALLY WEAKEN. HOWEVER...ADDITIONAL STORMS WILL
LIKELY DEVELOP FARTHER WEST CROSS PARTS OF AL AND MS NORTH OF THE
STATIONARY FRONT AS THE LOW LEVEL JET STRENGTHENS DOWNSTREAM FROM
SHORTWAVE TROUGH OVER THE PLAINS.
..DIAL.. 03/15/2008
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NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
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