Friday, December 14, 2007

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 141956
SWODY1
SPC AC 141953

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0153 PM CST FRI DEC 14 2007

VALID 142000Z - 151200Z

..NO SVR TSTM AREAS FORECAST...

..FLORIDA...
AN INFLUX OF MOISTURE IS ONGOING ASSOCIATED WITH A TROPICAL WAVE
EXTENDING NORTH OF REMNANTS OF OLGA...NOW OVER THE NORTHWESTERN
CARIBBEAN. AND...A BOUNDARY LAYER CHARACTERIZED BY 70F+ SURFACE DEW
POINTS HAS OVERSPREAD MUCH OF THE CENTRAL/SOUTHERN PENINSULA.
SURFACE HEATING HAS CONTRIBUTED TO DESTABILIZATION OVER INLAND
AREAS...WHERE INHIBITION HAS DIMINISHED WITH WEAKENING OF UPPER
SUBTROPICAL RIDGE. THIS HAS ALLOWED FOR SCATTERED ONGOING
THUNDERSTORM ACTIVITY...WHICH IS EXPECTED TO SPREAD NORTHWARD
THROUGH MUCH OF THE REMAINDER OF THE CENTRAL PENINSULA BY EARLY
EVENING. THEREAFTER...IT SEEMS PROBABLE THAT THUNDERSTORMS WILL
ONCE AGAIN BECOME CONFINED TO OFFSHORE WATERS...AS RADIATIONAL
COOLING/STABILIZATION OF THE BOUNDARY LAYER PROCEEDS.

..SOUTHERN PLAINS INTO LOWER MISSISSIPPI VALLEY...
A RELATIVELY MODEST RETURN FLOW OF MOISTURE APPEARS UNDERWAY OFF THE
WESTERN GULF OF MEXICO INTO CENTRAL/EASTERN TEXAS. AND...A
SOUTHERLY LOW-LEVEL JET IS BEGINNING TO STRENGTHEN ACROSS CENTRAL
TEXAS...AS THE EVOLVING AMPLIFIED UPSTREAM TROUGH PROGRESSES INTO
THE ROCKIES.

40-50 KT SOUTHERLY 850 FLOW IS PROGGED TO DEVELOP NORTHEASTWARD
THROUGH PARTS OF SOUTHEAST OKLAHOMA AND THE ARKLATEX BY EARLY
EVENING...AS A FRONTAL WAVE BEGINS TO FORM ALONG A STRENGTHENING
FRONTAL ZONE ACROSS EASTERN TEXAS INTO THE LOWER MISSISSIPPI VALLEY.
THIS SHOULD CONTRIBUTE TO STEEPENING ISENTROPIC ASCENT AND
LOWER/MID TROPOSPHERIC DESTABILIZATION. BY 15/02-03Z...AS
MOISTENING PARCELS BEGIN TO REACH LEVELS OF FREE CONVECTION...
SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ABOVE THE FRONTAL
INVERSION...ACROSS PARTS OF NORTH CENTRAL/NORTHEAST TEXAS THROUGH
SOUTHEASTERN OKLAHOMA INTO WESTERN ARKANSAS.

AS THE UPPER TROUGH PROCEEDS INTO THE PLAINS LATER TONIGHT...
ACTIVITY SHOULD GRADUALLY SPREAD EASTWARD TOWARD THE LOWER
MISSISSIPPI VALLEY. ADDITIONAL STORMS ARE ALSO EXPECTED TO DEVELOP
SOUTHWARD THROUGH EASTERN TEXAS...TOWARD MID/UPPER TEXAS COASTAL
AREAS...AS MID-LEVEL INHIBITION FINALLY BEGINS TO WEAKEN AHEAD OF AN
EASTWARD ADVANCING COLD FRONT. WEAK CAPE SEEMS LIKELY TO MINIMIZE
HAIL POTENTIAL. AND...A NEUTRAL TO STABLE NEAR SURFACE LAYER...EVEN
AHEAD OF COLD FRONT...AS FAR SOUTH AS THE COASTAL PLAINS...PROBABLY
WILL MINIMIZE DAMAGING WIND/TORNADO POTENTIAL THROUGH THE END OF
THIS PERIOD...DESPITE INCREASINGLY FAVORABLE SHEAR PROFILES FOR
SUPERCELLS.

..PACIFIC NORTHWEST...
THE SHORT WAVE TROUGH APPROACHING COASTAL AREAS IS PROGGED TO REMAIN
STRONG...UNTIL WEAKENING AS IT ADVANCES INLAND...AND EAST OF THE
CASCADES EARLY SATURDAY. STRONG MID-LEVEL COOLING...WITH A 500 MB
COLD CORE OF -26 TO -30C...IS PROGGED TO ACCOMPANY SYSTEM...AND MAY
SUPPORT A FEW THUNDERSTORMS AS A WEAK TO MODERATE LOW-LEVEL ONSHORE
FLOW DEVELOPS BY 12Z SATURDAY.

.KERR.. 12/14/2007

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