SPC AC 101625
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
ISSUED BY 15TH OWS SCOTT AIR FORCE BASE IL
1025 AM CST THU DEC 10 2009
VALID 101630Z - 111200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
DEEP POLAR VORTEX WILL LINGER OVER N CNTRL CANADA THIS PERIOD AS SRN
EXTENSION OF THE SYSTEM...NOW CENTERED NEAR JAMES BAY... FURTHER
ELONGATES E INTO THE CANADIAN MARITIMES/GULF OF ST LAWRENCE. AS
THIS OCCURS...EXPECT HEIGHTS TO RISE ACROSS THE RCKYS...PLNS AND MS
VLY TODAY...AND OVER THE OH VLY/LWR GRT LKS TONIGHT/EARLY SAT. AT
SFC...COLD FRONT ASSOCIATED WITH ERN CANADIAN VORTEX WILL SETTLE
STEADILY S ACROSS THE FL PENINSULA TODAY...AND ACROSS THE FL STRAITS
EARLY FRI.
...FL...
SCTD DIURNALLY-ENHANCED STORMS EXPECTED THROUGH LATE THIS AFTN ALONG
AND AHEAD OF SWD-MOVING COLD FRONT OVER CNTRL/SRN FL. ALTHOUGH MID
LVL LAPSE RATES WILL REMAIN WEAK...COMBINATION OF HEATING WITH
SEASONABLY RICH MOISTURE SHOULD YIELD 1000-1500 J/KG MLCAPE.
MODERATE...DEEP UNIDIRECTIONAL WSW FLOW ALSO WILL BE PRESENT... WITH
35-40 KT CLOUD-LAYER SHEAR GIVEN 60+ KT FLOW AT 300 MB. SETUP MAY
THEREFORE SUPPORT A FEW SUSTAINED CELLS AND/OR SMALL BOWS WITH STG
WINDS...ESPECIALLY ALONG THE E CST. WEAKENING FRONTAL
CONVERGENCE...ABSENCE OF LARGE SCALE FORCING FOR ASCENT...AND WEAK
MID LVL LAPSE RATES SUGGEST...HOWEVER...THAT ANY SVR THREAT WILL
REMAIN TOO ISOLD TO WARRANT CONDITIONAL PROBABILITIES .
...DOWNWIND OF THE GRT LKS...
LOW TO MID LVL W TO WNWLY FLOW OVER THE GRT LKS REGION WILL SHOW
MINOR FLUCTUATIONS IN DIRECTION AS SEVERAL LOW AMPLITUDE
DISTURBANCES MOVE ACROSS REGION. OVERALL...HOWEVER...BOUNDARY LAYER
FLOW WILL REMAIN STRONG AND UNIDIRECTIONAL. COUPLED WITH FAIRLY
STEEP LOW LVL LAPSE RATES AND SIZABLE AIR/WATER TEMPERATURE
DIFFERENCES...SETUP WILL REMAIN FAVORABLE FOR QSTNRY/REGENERATIVE
CONVECTIVE PLUMES. THESE MAY BECOME ESPECIALLY PERSISTENT DOWNWIND
OF LKS ERIE AND ONTARIO...AND MAY YIELD ISOLD/INTERMITTENT LIGHTNING
WITH LITTLE DIURNAL VARIATION.
..15_OWS.. 12/10/2009
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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