SPC AC 040545
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1245 AM CDT SUN OCT 04 2009
VALID 051200Z - 061200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
UPPER LOW OVER ERN CANADA IS PROGGED TO DRIFT SLOWLY EWD TOWARD ERN
QUEBEC/NRN NEW ENGLAND...WHILE A LARGE POSITIVELY-TILTED TROUGH
REMAINS IN PLACE FROM THE N CENTRAL U.S. SWWD ACROSS THE ROCKIES.
AN UPPER LOW EMBEDDED WITHIN THE WRN TROUGH -- INITIALLY OVER THE
GREAT BASIN/SRN ID/WRN UT REGION -- IS PROGGED TO EJECT EWD WITH
TIME...THOUGH MODELS CONTINUE TO TREND SLOWER WITH THIS EJECTION.
LATEST RUNS SHIFT THIS FEATURE ACROSS THE NRN HIGH PLAINS INTO THE
DAKOTAS REGION THROUGH THE END OF THE PERIOD.
AT THE SURFACE...A COLD FRONT WILL CONTINUE CROSSING THE ROCKIES
THROUGH THE FIRST HALF OF THE PERIOD. THIS LOW WILL THEN REDEVELOP
NEWD ALONG THE ADVANCING FRONT...FROM ERN CO NEWD INTO/ACROSS THE
MID MO VALLEY REGION LATE. AS THIS OCCURS...THE TRAILING FRONT WILL
SHIFT ACROSS THE CENTRAL PLAINS...AND SHOULD EXTEND FROM NERN
KS/NWRN MO SWWD ACROSS OK AND INTO FAR W TX BY THE END OF THE
PERIOD.
...S CENTRAL CONUS...
WITH A SLOWER EJECTION OF THE UPPER FEATURE INTO THE PLAINS...AND
THUS SLOWER PROGRESSION OF THE SURFACE FRONT INTO/ACROSS THE
PLAINS...POTENTIAL SEVERE EVENT FORECAST FOR MON APPEARS
INCREASINGLY MARGINAL.
MORE EXTENSIVE WARM SECTOR CAPPING IS NOW FORECAST ACROSS NRN AND
CENTRAL TX...WITH THE FRONT STILL WELL TO THE W. SOME CONVECTIVE
DEVELOPMENT MAY OCCUR NEAR A LEE TROUGH...BUT LACK OF STRONGER
LOW-LEVEL CONVERGENCE -- AS STRONGER UPPER FORCING REMAINS WELL TO
THE N -- SUGGESTS ONLY MARGINAL SEVERE POTENTIAL. DEGREE OF
INSTABILITY AND MODERATE SHEAR COULD SUPPORT A FEW STRONGER
CELLS...CAPABLE OF GUSTY WINDS AND MARGINAL HAIL.
FARTHER N ACROSS THE RED RIVER AND INTO KS...STORMS ARE PROGGED TO
REMAIN ELEVATED...AS LESS ROBUST NWD RETURN OF HIGHER THETA-E
BOUNDARY LAYER AIR WILL BE ANOTHER CONSEQUENCE OF THE SLOWER
EJECTION OF THIS STORM SYSTEM. WHILE STRONG SHEAR AND 500 TO 1000
J/KG ELEVATED CAPE COULD ALLOW A FEW STRONGER STORMS TO PRODUCE
MARGINAL HAIL...OVERALL THREAT DOES NOT APPEAR TO WARRANT ANY MORE
THAN 5% SEVERE PROBABILITY.
..GOSS.. 10/04/2009
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
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