SPC AC 270718
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0218 AM CDT SUN SEP 27 2009
VALID 291200Z - 301200Z
...SYNOPSIS...
MODELS INDICATE THAT THE GREAT LAKES CYCLONE WILL CONTINUE TO WEAKEN
DURING THIS FORECAST PERIOD...WHILE SLOWLY LIFTING INTO
QUEBEC...WHERE IT APPEARS LIKELY TO STALL AS IT BECOMES INCREASINGLY
CUT OFF FROM STRONGER FLOW. BROADLY CYCLONIC MID/UPPER FLOW IS
EXPECTED TO LINGER...HOWEVER...ACROSS MOST AREAS EAST OF THE
MISSISSIPPI VALLEY...WHILE THE SOUTHERN PORTION OF THE AMPLIFIED
UPSTREAM TROUGH TURNS EASTWARD...INLAND OF CENTRAL PACIFIC COASTAL
AREAS. THE 27/00Z ECMWF AND GFS ARE BOTH SIMILAR WITH THE
PROGRESSIVENESS OF THIS LATTER FEATURE THROUGH EARLY
WEDNESDAY...MAINTAINING A SLOW EASTWARD MOTION INTO THE GREAT BASIN
BY 30/12Z. ASSOCIATED FORCING IS PROGGED TO SUPPORT A DEVELOPING
SURFACE CYCLONE WITHIN A DEEPENING SURFACE TROUGH TO THE LEE OF THE
NORTHERN/CENTRAL ROCKIES. THIS WILL LIKELY BE ACCOMPANIED BY A
STRENGTHENING SOUTHERLY LOW-LEVEL JET...THOUGH MOSTLY WITHIN THE
DRIER ENVIRONMENT ACROSS THE NORTHERN AND CENTRAL PLAINS. AS A
RESULT...HIGHER MOISTURE CONTENT AIR IS EXPECTED TO REMAIN SLOW TO
ADVECT NORTH OF THE LOWER RIO GRANDE VALLEY...AND CONVECTIVE
POTENTIAL APPEARS LOW ACROSS THE PLAINS...IN ADDITION TO MUCH OF THE
REMAINDER OF THE U.S...TUESDAY/TUESDAY NIGHT.
..KERR.. 09/27/2009
CLICK TO GET WUUS03 PTSDY3 PRODUCT
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z
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