Saturday, September 19, 2009

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 191625
SWODY1
SPC AC 191622

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1122 AM CDT SAT SEP 19 2009

VALID 191630Z - 201200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
A PRONOUNCED NRN STREAM MID LEVEL TROUGH IS MOVING EWD OVER WA/ORE
THIS MORNING...AND WILL CONTINUE EWD OVER THE NRN ROCKIES THROUGH
TONIGHT. INCREASING HEIGHT FALLS AND MEAN FLOW OVER THE PLAINS
/DOWNSTREAM FROM THE PAC NW TROUGH/ WILL BEGIN TO RESULT IN SLOW EWD
PROGRESSION OF THE SERIES OF VORTICITY CENTERS EMBEDDED IN THE
BROAD/WEAK LOW NOW CENTERED OVER KS/OK.

THE RICHEST MOISTURE PLUME AND MORE CONCENTRATED CONVECTION IS
EXPECTED TODAY OVER TN/AL IN ADVANCE OF DIFFUSE EMBEDDED MID LEVEL
TROUGH OVER THE LOWER MS VALLEY...WHICH WILL TEND TO SPREAD SLOWLY
NWD OVERNIGHT IN RESPONSE TO THE AMPLIFYING UPSTREAM FLOW REGIME
OVER THE ROCKIES AND CENTRAL/NRN PLAINS. ELSEWHERE...SCATTERED
/MAINLY DIURNAL/ THUNDERSTORMS WILL AGAIN OCCUR TODAY IN ASSOCIATION
WITH DAYTIME HEATING AND ENHANCED MOISTURE/ASCENT WITH THE DIFFUSE
EMBEDDED VORTICITY CENTERS OVER THE FOUR CORNERS STATES. SOME
PORTION OF THE LOW-MID LEVEL MOISTURE PLUME OVER THE NRN GREAT BASIN
/PER THE 12Z SLC SOUNDING/ WILL SPREAD NWD TO SW MT BY LATE
AFTERNOON ALONG THE COLD FRONT WITH THE PAC NW MID LEVEL TROUGH.
GUSTY WINDS WILL BE POSSIBLE WITH HIGH-BASED THUNDERSTORMS...BUT THE
SEVERE STORM THREAT APPEARS QUITE MARGINAL AT BEST.

..THOMPSON/SMITH.. 09/19/2009

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.

No comments: