Wednesday, October 26, 2011

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 260527
SWODY1
SPC AC 260525

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1225 AM CDT WED OCT 26 2011

VALID 261200Z - 271200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
BROAD SW FLOW WILL EXIST ACROSS THE CNTRL PLAINS EWD TO THE ATLANTIC
COAST...WITH AN UPPER TROUGH AXIS MOVING ACROSS THE FOUR CORNERS
AROUND 00Z. BEHIND THIS FEATURE...UPPER RIDGING WILL BRIEFLY TAKE
PLACE OVER CA AND THE WRN GREAT BASIN WITH GRADUALLY FALLING HEIGHTS
OVER THE PACIFIC NW. A COLD FRONT WILL MOVE FROM A SRN LOWER MI/SRN
MO/NWRN TX LINE AT 12Z TO A NEW YORK CITY/OH RIVER VALLEY/RED RIVER
VALLEY LINE BY 00Z. A THIN RIBBON OF LOW LEVEL MOISTURE WILL AID IN
THUNDERSTORM DEVELOPMENT NEAR THE COLD FRONT...WITH SLIGHTLY HIGHER
DEWPOINTS FROM TX INTO AR WHERE STRONGER STORMS WILL BE POSSIBLE.

...WRN AND NRN AR...FAR ERN OK...SERN MO...
SOME GRADUAL COOLING ALOFT WILL OCCUR THROUGHOUT THE DAY AS THE
UPPER TROUGH MOVES INTO THE SRN HIGH PLAINS LATE. SWLY SURFACE WINDS
AHEAD OF THE FRONT WILL ALLOW FOR BOUNDARY LAYER DEWPOINTS TO RISE
INTO THE LOWER 60S AS FAR N AS THE AR/MO BORDER BY 00Z. ALTHOUGH LOW
LEVEL LAPSE RATES IN GENERAL ACROSS THE REGION WILL BE POOR TO
MARGINAL OWING TO TRAJECTORIES OUT OF THE SURFACE HIGH TO THE SE...A
PLUME OF RELATIVELY STEEPER LOW LEVEL LAPSE RATES IS EXPECTED TO
DEVELOP DUE TO HEATING FROM NERN TX INTO AR AND ERN MO. FORECAST
SOUNDINGS INDICATE SOME CAPPING/WARM LAYER JUST BELOW 700 MB...BUT
FORCING ALONG THE COLD FRONT SHOULD YIELD AT LEAST ISOLATED
THUNDERSTORMS BY LATE AFTERNOON.

DEEP LAYER SHEAR PROFILES WILL BE FAVORABLE FOR ORGANIZATION AND
GIVEN ORIENTATION PARALLEL TO THE FRONT...SMALL BOWS CAPABLE OF
STRONG TO LOCALLY SEVERE WIND GUSTS APPEARS TO BE THE MAIN THREAT. A
FEW OF THESE BOWS MAY EVEN DEVELOP INFLECTION POINTS ON RADAR WITH
WHAT APPEAR TO BE AREAS OF ROTATION. DESPITE WEAK
INSTABILITY...STRONG SHEAR COUPLED WITH COOL TEMPERATURES ALOFT
SUGGEST A FEW CORES MAY PRODUCE LOW END SEVERE HAIL.

..JEWELL/HURLBUT.. 10/26/2011

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