SWODY1
SPC AC 050552
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1152 PM CST THU FEB 04 2010
VALID 051200Z - 061200Z
...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN AND TONIGHT
ACROSS THE FLORIDA PENINSULA...
...SYNOPSIS...
MODELS SUGGEST THAT A BLOCKING RIDGE WILL BECOME MORE PROMINENT TO
THE LEE OF THE CANADIAN ROCKIES DURING THIS FORECAST PERIOD...
WITHIN A NORTHERN BRANCH OF THE PREVAILING SPLIT UPPER FLOW PATTERN.
AS THIS OCCURS...AN ELONGATING UPPER TROUGH APPROACHING THE PACIFIC
COAST APPEARS LIKELY TO GRADUALLY BREAK APART...WITH A SIGNIFICANT
PORTION LIFTING NORTHWARD TOWARD THE BRITISH COLUMBIA COAST...AND
ANOTHER DIGGING TOWARD THE CALIFORNIA COAST. SHORT WAVE RIDGING
AHEAD OF THE SOUTHERN FEATURE IS PROGGED TO SLOWLY SHIFT ACROSS THE
SOUTHERN GREAT BASIN/ROCKIES ...WHILE DOWNSTREAM SHORT WAVE IMPULSES
REMAIN PROGRESSIVE WITHIN A CONSOLIDATING BELT OF WESTERLIES ACROSS
THE GULF COAST AND SOUTHERN ATLANTIC COAST STATES. GUIDANCE
INDICATES THAT THE LEAD IMPULSE...CURRENTLY EMERGING FROM THE
MEXICAN PLATEAU AND RIO GRANDE VALLEY...WILL LIFT ACROSS THE
SOUTHEASTERN STATES IN INCREASINGLY SHEARED FASHION...AS THE NEXT
INTENSIFYING IMPULSE DIGS FROM THE CENTRAL PLAINS THROUGH THE
SOUTHERN APPALACHIANS BY 12Z SATURDAY. ASSOCIATED FORCING APPEARS
LIKELY TO SUPPORT STRONG SURFACE CYCLOGENESIS ALONG A FRONTAL ZONE
ACROSS THE PIEDMONT AND COASTAL PLAIN OF GEORGIA AND THE CAROLINAS
THIS AFTERNOON INTO TONIGHT.
...FLORIDA...
AN INITIALLY DRY/STABLE ENVIRONMENT ACROSS MUCH OF THE PENINSULA
PROVIDES AT LEAST SOME UNCERTAINTY CONCERNING THE CONVECTIVE
POTENTIAL TODAY. BUT...CONSIDERABLE BOUNDARY LAYER MOISTENING HAS
OCCURRED OVER THE EASTERN GULF OF MEXICO DURING THE PAST 24
HOURS...AND AN INFLUX OF MID/HIGH LEVEL MOISTURE FROM THE PACIFIC IS
ACCOMPANYING THE SOUTHERN SHORT WAVE. THE MID-LEVELS ARE FAIRLY
WARM ACROSS THE REGION...WITH LITTLE IN THE WAY OF COLD ADVECTION
ANTICIPATED PRIOR TO COLD FRONTAL PASSAGE DURING THE EVENING HOURS.
HOWEVER...FORECAST SOUNDINGS ARE SUGGESTIVE THAT EVAPORATION OF
PRECIPITATION ALOFT WILL RESULT IN A GRADUAL COOLING FROM HIGH INTO
MID-LEVELS LATER THIS AFTERNOON AND EVENING...AS BOUNDARY LAYER
MOISTURE ADVECTS INLAND ACROSS THE PENINSULA. IT APPEARS PROBABLE
THAT MID/UPPER 60S DEW POINTS WILL BECOME SUFFICIENT FOR AT LEAST
WEAK BOUNDARY LAYER BASED CAPE ON THE ORDER OF 500 J/KG.
BOUNDARY LAYER DESTABILIZATION...COUPLED WITH THE DEVELOPMENT OF
LARGE CLOCKWISE CURVED LOW-LEVEL HODOGRAPHS...AS A 50-60 KT
SOUTHERLY 850 MB JET AXIS SHIFTS ACROSS THE PENINSULA AHEAD OF THE
COLD FRONT LATE THIS AFTERNOON/EVENING...WILL BE SUPPORTIVE OF
INCREASING SEVERE POTENTIAL AS CONVECTION FORMS. THERE ARE SOME
INDICATIONS THAT THIS COULD OCCUR WITH A SECONDARY SYNOPTIC OR
SUB-SYNOPTIC SURFACE LOW MIGRATING INLAND OFF THE EASTERN GULF OF
MEXICO. THIS MAY ACCOMPANY AN ORGANIZED MESOSCALE CONVECTIVE
SYSTEM...BUT DISCRETE STORMS ALSO APPEAR POSSIBLE...WITH THE RISK
FOR TORNADOES...IN ADDITION TO STRONG...POTENTIALLY DAMAGING... WIND
GUSTS. SEVERE POTENTIAL COULD BEGIN TO INCREASE ACROSS THE CENTRAL
PENINSULA BY 05/21Z...BUT HIGHEST SEVERE PROBABILITIES CURRENTLY
APPEAR TO EXIST SOUTH OF THE INTERSTATE 4 CORRIDOR INTO THE FORT
MYERS/PALM BEACH AREAS DURING THE 06/00-06Z TIME FRAME.
...SRN GEORGIA INTO THE ERN CAROLINAS...
POTENTIAL FOR BOUNDARY LAYER DESTABILIZATION IS STILL UNCLEAR.
HOWEVER...GIVEN THE LIKELIHOOD OF A RAPIDLY DEEPENING SURFACE
CYCLONE MIGRATING ACROSS THE REGION LATE THIS AFTERNOON AND
TONIGHT...ASSOCIATED FORCING AND SHEAR SUPPORT NON-NEGLIGIBLE
PROBABILITIES FOR SEVERE STORMS CAPABLE OF PRODUCING DAMAGING
WINDS/TORNADOES.
..KERR.. 02/05/2010
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