DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 270600
SWODY1
SPC AC 270558

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1258 AM CDT MON AUG 27 2012

VALID 271200Z - 281200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF FL/GULF
COAST REGION...

...FL PENINSULA/GULF COAST REGION...
REFERENCE THE NATIONAL HURRICANE CENTER FOR THE LATEST DETAILS AND
FORECASTS REGARDING ISAAC. ISAAC WILL LIKELY CONTINUE A GENERAL
NORTHWESTWARD DRIFT OVER THE EASTERN GULF OF MEXICO THROUGH TONIGHT.
ESPECIALLY WITH THE LIKELIHOOD OF GRADUAL INTENSIFICATION...AN
ENVELOPE OF STRONG WINDS ON THE EASTERN PERIPHERY OF ISAAC WILL BE
CONDUCIVE FOR MINI-SUPERCELLS AND A RISK FOR TORNADOES WITH OUTER
BANDS. DIURNAL HEATING/MODEST CLOUD BREAKS SHOULD ESPECIALLY BOOST
UPDRAFT STRENGTH AND THE POSSIBILITY OF TORNADOES WITHIN A
MOISTURE-RICH AND AMPLE LOW-LEVEL SHEAR/SRH ENVIRONMENT. GIVEN THE
LONGEST RESIDENCE TIME OF STRONGEST S/SE WINDS WITHIN THE LOWEST 1-3
KM...THIS WILL ESPECIALLY BE THE CASE FOR THE WESTERN/CENTRAL FL
PENINSULA. AN ISOLATED TORNADO THREAT MAY DEVELOP INTO THE FL
PANHANDLE BY TONIGHT...AND ADDITIONAL PARTS OF THE GULF COASTAL
REGION INCLUDING FAR SOUTHERN AL/MS AND SOUTHEAST LA BY EARLY
TUESDAY.

...SD/WESTERN NEB...
WHILE THE UPPER RIDGE WILL CONTINUE TO BUILD OVER THE
REGION...ISOLATED TSTMS MAY DEVELOP THIS AFTERNOON/EARLY EVENING
NEAR A FRONTAL BOUNDARY ACROSS SD...OR MORE LIKELY...NEAR A SURFACE
TROUGH /AND BLACK HILLS VICINITY/ ACROSS WESTERN PORTIONS OF NEB/SD.
AIDED BY A DEGREE OF VEERING AND STRONG HIGH LEVEL FLOW...SUFFICIENT
VERTICAL SHEAR/CAPE AND A DEEPLY MIXED BOUNDARY LAYER MAY ACCOUNT
FOR A MARGINAL SEVERE WIND /AND PERHAPS HAIL/ POTENTIAL THIS
AFTERNOON/EARLY EVENING.

...UPPER OH VALLEY...
TSTMS SHOULD RE-INTENSIFY THIS AFTERNOON AHEAD OF A VORT MAX/COLD
FRONT SPREADING EASTWARD ACROSS THE MIDWEST/UPPER OH VALLEY. POCKETS
OF SOMEWHAT STRONGER PRE-FRONTAL HEATING AND GRADUAL LOW-LEVEL
MOISTENING WILL ALLOW FOR AT LEAST WEAK DESTABILIZATION THIS
AFTERNOON...WHILE MODESTLY STRONG VERTICAL SHEAR /AS MUCH AS 30 KT
0-6 KM/ SHOULD ACCOMPANY THE AFOREMENTIONED VORT MAX. WHILE LIKELY
TO BE MARGINAL...THIS SCENARIO MAY BE SUFFICIENT FOR A FEW
STRONGER/POTENTIALLY SEVERE TSTMS CAPABLE OF LOCALIZED WIND DAMAGE.

...SOUTHERN AZ...
AS EASTERLY STEERING FLOW POTENTIALLY INCREASES ON THE SOUTHERN
PERIPHERY OF THE UPPER RIDGE...IT IS POSSIBLE THAT A FEW STRONG
TSTMS COULD DEVELOP ON THE HIGHER TERRAIN AND PROPAGATE TOWARD THE
DESERT FLOOR. HOWEVER...WITH THE POSSIBILITY OF SOME DRYING FROM THE
EAST...THE EXACT DEGREE OF DESTABILIZATION AND SUBSEQUENT STORM
VIGOR/COVERAGE IS UNCERTAIN. OVERALL...ANY SEVERE WIND POTENTIAL
APPEARS SUFFICIENTLY LOW TO PRECLUDE PROBABILITIES.

...TX...
ISOLATED TO SCATTERED TSTMS SHOULD REDEVELOP/INCREASE AND DRIFT
GENERALLY SOUTHWARD THIS AFTERNOON WITHIN A CORRIDOR ACROSS
SOUTHWEST/CENTRAL TX TO THE ARKLATEX/LOWER MS VALLEY. AN ISOLATED
DOWNBURST CANNOT BE ENTIRELY RULED OUT LATE THIS AFTERNOON/EARLY
EVENING...BUT WEAK MASS CONVERGENCE/LIMITED DESTABILIZATION SUGGESTS
NOTHING MORE THAN A VERY LIMITED POTENTIAL.

..GUYER/ROGERS.. 08/27/2012

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.