SWODY1
SPC AC 261259
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0659 AM CST THU JAN 26 2012
VALID 261300Z - 271200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL GULF CST STATES
NEWD INTO THE CAROLINAS/SRN VA...
...SYNOPSIS...
NE TX UPR LOW HAS BEGUN TO EJECT NEWD AS IT BECOMES RE-ABSORBED
WITHIN THE MAIN BELT OF THE WLYS AND PHASES WITH IMPULSE MOVING SE
ACROSS THE LWR MO VLY. THE PHASED TROUGH SHOULD REACH THE SRN
APPALACHIANS BY 12Z THU...WITH A BROAD SWATH OF 90 TO 120 M HEIGHT
FALLS BY THAT TIME EXPECTED TO EXTEND DOWNSTREAM INTO THE CAROLINAS
AND MID ATLANTIC.
AT LWR LEVELS...ELONGATED SFC LOW NOW OVER THE LWR MS VLY SHOULD
BECOME BETTER DEFINED TODAY...AND LIKELY WILL BE CENTERED NEAR
NASHVILLE THIS EVE. THE LOW IS EXPECTED TO MARKEDLY DEEPEN AS IT
ACCELERATES NEWD TNGT/EARLY FRI...REACHING WRN NY BY THE END OF THE
PERIOD.
COLD FRONT EXTENDING SSW FROM DEVELOPING SFC LOW...AND PRE-FRONTAL
OUTFLOW BOUNDARY/SQLN...EXPECTED TO BE THE MAIN FOCI FOR STRONG TO
SVR TSTMS TODAY AS THOSE FEATURES CONTINUE MOVING GENERALLY ENE
ACROSS THE CNTRL GULF CST REGION. LATER TNGT AND EARLY
FRI...REMNANTS OF THE FRONTAL ACTIVITY...OR NEW STORMS...ARE
EXPECTED TO AFFECT THE ERN SLOPES OF THE SRN APPALACHIANS AND THE
ADJACENT PIEDMONT/CSTL PLNS. THIS ACTIVITY MAY POSE A RENEWED SVR
THREAT...ESPECIALLY AFTER 06Z.
...CNTRL GULF CST STATES TODAY THROUGH EARLY TNGT...
EWD PROGRESSION OF UPR LOW WILL MAINTAIN BROAD INFLOW OF
MOISTURE-RICH AIR /PW AOA 1.5 INCHES/ AHEAD OF COLD FRONT CROSSING
THE GULF CST STATES. COUPLED WITH SFC HEATING AND LARGE SCALE
ASCENT ASSOCIATED WITH EJECTING UPR TROUGH...SETUP SHOULD SUPPORT
STRENGTHENING OF EXISTING PRE-FRONTAL SQLN...ESPECIALLY AS COLD
FRONT OVERTAKES IT LATER THIS MORNING. IN ADDITION...PERSISTENT
CONFLUENCE IN MOIST INFLOW ENVIRONMENT COULD YIELD A FEW DISCRETE
STORMS AHEAD OF THE FRONTAL BAND.
WHILE MID LVL LAPSE RATES WILL NOT BE STEEP...PRESENCE OF RICH
BOUNDARY LAYER MOISTURE WITH MODERATE TO STRONG...LARGELY
UNIDIRECTIONAL SSWLY FLOW SUGGEST LIKELIHOOD FOR BROKEN LINE
SEGMENTS CONTAINING SUSTAINED STORMS/LEWPS AND OCCASIONAL
SUPERCELLS. THESE WILL BE CAPABLE OF DMGG WIND AND POSSIBLY
TORNADOES...ESPECIALLY NEAR THE CST WHERE SFC DEW POINTS WILL RISE
INTO UPR 60S TO NEAR 70 F.
THE STORMS SHOULD REACH WRN GA LATER TODAY AND PERSIST THROUGH THIS
EVE. NIGHTFALL AND INFLUENCE OF RESIDUAL WEDGE-TYPE AIR MASS MAY
RESULT IN SOME WEAKENING OF STORM INTENSITY/COVERAGE.
NEVERTHELESS...SOME SVR THREAT LIKELY WILL CONTINUE ACROSS GA AND
ADJACENT PARTS OF THE SRN APPALACHIANS THROUGH LATE TNGT GIVEN
STRENGTH OF FLOW/MOISTURE INFLOW ABOVE SHALLOW STABLE LAYER.
...ERN AR THROUGH CNTRL/NRN MS AND WRN AL THIS AFTN...
WDLY SCTD STRONG TO SVR STORMS MAY FORM THIS AFTN OVER CNTRL/NRN MS
AREA...NEAR TRACK OF SFC LOW AND ASSOCIATED W-E COLD FRONTAL SURGE.
WHILE LOW LVL WINDS WILL BE MODEST AND VEERED TO WSWLY...STRONG SSW
FLOW ALOFT AND MID LVL COOLING/DPVA SUGGEST POTENTIAL FOR A FEW
SUSTAINED UPDRAFTS/POSSIBLE SUPERCELLS WITH HAIL.
...CAROLINAS/SRN VA EARLY FRI...
MODERATE TO STRONG FORCING FOR ASCENT ASSOCIATED WITH PHASING UPR
TROUGH WILL OVERSPREAD ZONE OF RAPID LOW LVL MOISTENING ALONG THE
ERN SLOPES OF THE SRN APPALACHIANS EARLY FRI. AT THE SAME
TIME...LOW TO MID LVL FLOW WILL SUBSTANTIALLY INCREASE...WITH 850 MB
SSWLY WINDS INCREASING TO AOA 60 KTS. THIS SETUP MAY SUPPORT
REJUVENATION OF EXISTING BANDS OF STORMS CROSSING THE SRN
APPALACHIANS FROM THE TN VLY...AND/OR NEW DEVELOPMENT ALONG LEE
TROUGH JUST E OF THE MOUNTAINS. VERY STRONG LOW LVL FLOW/SHEAR
SUGGEST A CONDITIONAL THREAT OR BOTH DMGG WIND AND TORNADOES WITH
ANY SUSTAINED STORMS THAT DO FORM.
..CORFIDI/JIRAK.. 01/26/2012
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