SPC AC 070046
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0746 PM CDT WED OCT 06 2010
VALID 070100Z - 071200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
PRIMARY UPPER AIR FEATURE REMAINS LARGE/SLOW-MOVING CYCLONIC GYRE
OVER WRN CONUS. MOISTURE CHANNEL IMAGERY INDICATES SEVERAL EMBEDDED
SHORTWAVE PERTURBATIONS ORBITING MAIN CENTER OF THIS CYCLONE...WHICH
HAS SHOWN SLIGHT NET RETROGRESSION ACROSS PORTIONS CENTRAL/NRN CA
DURING PAST SEVERAL HOURS. AS HEIGHTS FALL OFFSHORE PAC NW THROUGH
REMAINDER PERIOD...CA CYCLONE SHOULD STOP RETROGRESSION AND MOVE
SLOWLY NEWD...WITH POSSIBLE RE-FORMATION OF MEAN CENTER ACROSS
SIERRA NV TOWARD RNO AREA BEFORE 12Z. MEANWHILE...STG UPPER RIDGING
IS FCST TO HOLD FROM SRN HIGH PLAINS NWD ACROSS DAKOTAS...WHILE
MID-ATLANTIC UPPER CYCLONE EJECTS NEWD ACROSS NEW ENGLAND.
...WRN CO/S-CENTRAL WY...
NNEWD-MOVING SHORTWAVE TROUGH AND RELATED LARGE-SCALE
ASCENT...COMBINED WITH LOW-LEVEL FORCING ALONG COLLECTIVE OUTFLOW
BOUNDARY -- HAS SUSTAINED ORGANIZED/BKN BAND OF TSTMS ACROSS ERN UT
INTO WRN CO DURING LAST FEW HOURS. ALTHOUGH THIS ACTIVITY IS MOVING
INTO AIR MASS THAT WILL BE UNDERGOING SFC COOLING...MRGL SVR HAIL
STILL MAY OCCUR FOR ANOTHER 1-2 HOURS. DAMAGING GUSTS ALSO ARE
POSSIBLE...WITH 53 KT GUST MEASURED AT RIL DURING PAST HOUR. REF
SPC MESOSCALE DISCUSSION 1936 FOR ADDITIONAL NEAR-TERM INFORMATION.
SVR POTENTIAL IS FCST TO DIMINISH THROUGH REMAINDER EVENING HOURS AS
TWO FACTORS COMBINE TO REDUCE AVAILABLE INSTABILITY -- SFC DIABATIC
HEATING AND EXPANDING COVERAGE OF OUTFLOW-COOLED BOUNDARY-LAYER AIR.
ELSEWHERE...WIDELY SCATTERED TO ISOLATED TSTMS WILL DIMINISH
GRADUALLY IN COVERAGE ACROSS WRN CONUS...BUT CONTINUE EPISODICALLY
FOR MUCH OF TONIGHT. CONVECTIVE POTENTIAL WILL BE MAXIMIZED BENEATH
POCKETS OF COLD AIR ALOFT ACCOMPANYING MID-UPPER VORTEX AND
ASSOCIATED SHORTWAVE TROUGHS...WHERE INTERACTING WITH FAVORABLE
LOW-MIDDLE LEVEL MOISTURE.
..EDWARDS.. 10/07/2010
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
|
