DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 260602
SWODY1
SPC AC 260600

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1200 AM CST TUE NOV 26 2013

VALID 261200Z - 271200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF FL AND ADJACENT
AL/GA...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CAROLINAS...

...SYNOPSIS...
A HIGHLY-AMPLIFIED LARGE SCALE PATTERN WILL REMAIN OVER THE CONUS
WITH INITIALLY SPLIT UPPER FLOW EAST OF THE ROCKIES. A POSITIVE-TILT
TROUGH OVER TX EARLY TODAY WILL BEGIN TO ACCELERATE EAST/EVENTUALLY
NORTHEASTWARD AS IT BECOMES MORE NEUTRAL/SLIGHT NEGATIVE-TILT OVER
THE GULF COAST STATES IN CONCERT WITH A SIGNIFICANTLY STRENGTHENING
UPPER JET /110+ KT AROUND 300 MB/. THIS UPPER TROUGH WILL
INCREASINGLY PHASE TONIGHT WITH A SOUTHEAST-MOVING/AMPLIFYING UPPER
TROUGH OVER THE MIDWEST/UPPER GREAT LAKES REGION. A QUICKLY
MODIFYING COLD/CONTINENTAL AIRMASS OVER FL/COASTAL SOUTHEAST STATES
AND A STEADY MOIST INFLUX WILL CONTRIBUTE TO AT LEAST SOME SEVERE
POTENTIAL ACROSS THE REGION THROUGH TONIGHT.

...SOUTHEAST AL AND GA/MUCH OF FL...
IN ADVANCE OF THE AFOREMENTIONED UPPER TROUGH/STRENGTHENING
JET...THE PRIMARY SURFACE LOW IS EXPECTED TO STEADILY DEEPEN/SPREAD
NORTHEASTWARD TODAY ACROSS SOUTHERN AL/FL PANHANDLE INTO
GA...ACCOMPANIED BY AN INCREASINGLY MOIST/BROAD WARM SECTOR WITH 60S
F SURFACE DEWPOINTS. RELATIVELY WIDESPREAD SHOWERS/SOME TSTMS AND
WEAK LAPSE RATES ALOFT WILL TEND TO HINDER THE DEGREE OF
DESTABILIZATION...ESPECIALLY WITH NORTHWARD EXTENT ACROSS AL/GA NEAR
THE ADVANCING SURFACE LOW/FRONTAL BOUNDARY.

CURRENT THINKING IS THAT THE FL PANHANDLE/COASTAL NORTH FL AND
EVENTUALLY WEST FL WILL BE MOST SUSCEPTIBLE TO AN INLAND-DEVELOPING
STRONG/SEVERE TSTM RISK DURING THE DAY. WEAK DESTABILIZATION AND
RELATIVELY STRONG SHEAR/LOW-LEVEL SRH WOULD SUPPORT BOTH
SEMI-DISCRETE SUPERCELLS AND BOWING SEGMENTS WITH AN ISOLATED
DAMAGING WIND/TORNADO RISK. IT IS POSSIBLE THAT THE MOST ORGANIZED
SEVERE RISK MAY NOT OCCUR UNTIL LATER THIS AFTERNOON INTO TONIGHT
ACROSS FL. GIVEN THE APPROACHING/AMPLIFYING UPSTREAM TROUGH
TONIGHT...STRENGTHENING FORCING FOR ASCENT/DEEP LAYER SHEAR COULD
CONTRIBUTE TO AN INLAND/EASTWARD-MOVING SQUALL LINE WITH POSSIBLE
PRECEDING SEMI-DISCRETE DEVELOPMENT ACROSS THE REMAINDER OF THE FL
PENINSULA. THIS WOULD INCLUDE AN ISOLATED DAMAGING WIND/SOME TORNADO
RISK.

...CAROLINAS...
A SEVERE RISK MAY DEVELOP/INCREASE INTO TONIGHT ACROSS
COASTAL/PERHAPS PIEDMONT PORTIONS OF THE CAROLINAS...ALTHOUGH
QUESTIONS REMAIN REGARDING THE DEGREE OF INLAND
MOISTENING/DESTABILIZATION ESPECIALLY GIVEN THE EXPECTED PREVALENCE
OF SHOWERS/TSTMS THIS AFTERNOON AND EVENING. A SURFACE LOW IS
EXPECTED TO DEVELOP/TRACK NORTHEASTWARD TONIGHT IN VICINITY OF THE
PROBABLE PIEDMONT FRONTAL ZONE...WITH AN INCREASINGLY BROAD/MOIST
WARM SECTOR WITH 60+ F SURFACE DEWPOINTS ACROSS THE COASTAL
CAROLINAS.

AS THE UPPER TROUGH APPROACHES...INCREASING VERTICAL SHEAR AND WEAK
CAPE WILL SUPPORT AT LEAST AN ISOLATED/CONDITIONAL SEVERE RISK
TONIGHT...ESPECIALLY NEAR/SOUTHEAST OF THE ADVANCING SURFACE LOW
WHERE SUFFICIENT MOISTURE/LOW-LEVEL DESTABILIZATION COULD SUPPORT A
SURFACE-BASED SEVERE TSTM RISK. INCREASINGLY LONG
HODOGRAPHS...ACCENTUATED BY 50-65 KT SOUTHERLY WINDS WITHIN THE
LOWEST 1-2 KM...COULD SUPPORT A COMBINATION OF LOW-TOPPED
SUPERCELLS/BOWING SEGMENTS CAPABLE OF ISOLATED INSTANCES OF WIND
DAMAGE AND TORNADOES.

..GUYER/GARNER.. 11/26/2013

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