SWOD48
SPC AC 180935
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0435 AM CDT FRI MAY 18 2007
VALID 211200Z - 261200Z
..DISCUSSION...
A MID LEVEL TROUGH OVER THE SE GULF OF AK AREA IS FORECAST TO MOVE
INLAND OVER BRITISH COLUMBIA AND THE PAC NW BY DAY 3...AND CONTINUE
SEWD TO THE NRN ROCKIES BY MON /DAY 4/...AND THEN PROGRESS OVER THE
CENTRAL/NRN PLAINS BY TUE-WED /DAYS 5-6/. THE LATEST GFS/MREF AND
ECMWF FORECASTS ARE IN REASONABLE AGREEMENT WITH THIS SCENARIO
THROUGH DAY 5...WHEREAS INCREASING DIFFERENCES ARE NOTED IN THE
EVOLUTION OF THIS TROUGH FROM DAY 6 INTO DAY 8 OVER THE MS VALLEY
AND GREAT LAKES.
LOW-LEVEL TRAJECTORIES WILL GRADUALLY VEER TO MORE ELY/SELY ACROSS
THE GULF BASIN BY EARLY NEXT WEEK...WHICH WILL ALLOW RICHER BOUNDARY
LAYER MOISTURE TO SPREAD NWD IN AT LEAST A NARROW CORRIDOR ACROSS
THE PLAINS. SCATTERED SEVERE STORMS WILL BE POSSIBLE ON MON /DAY 4/
ACROSS THE NRN PLAINS IN ASSOCIATION WITH A SURFACE FRONT AND HIGH
PLAINS CYCLOGENESIS IN ADVANCE OF THE NRN ROCKIES TROUGH. SEVERAL
DAYS OF EVAPOTRANSPIRATION AND SOME MOISTURE ADVECTION SHOULD ALLOW
SURFACE DEWPOINTS TO APPROACH 60 F...WHICH WILL CONTRIBUTE TO A
MODERATELY UNSTABLE WARM SECTOR. THE SEVERE THREAT AREA SHOULD
EXPAND SWD ON TUE /DAY 5/ AS A REMNANT LEE CYCLONE DEVELOPS SWD OVER
THE HIGH PLAINS...AND AS LOW-LEVEL MOISTURE INCREASES FROM S TO N
WHILE THE ROCKIES TROUGH BEGINS TO EMERGE OVER THE HIGH PLAINS.
.THOMPSON.. 05/18/2007
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write chris@lib.siu.edu.
No comments:
Post a Comment