SWOD48
SPC AC 310740
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0240 AM CDT MON OCT 31 2011
VALID 031200Z - 081200Z
...DISCUSSION...
MODELS ARE IN VERY GOOD AGREEMENT THROUGH MOST OF THE D4-8 PERIOD.
BEGINNING ON D4/THU...AN INITIAL UPPER LOW/TROUGH WILL MOVE FROM THE
LOWER TO MIDDLE MS VALLEY EWD TO THE MID ATLANTIC BY FRI MORNING.
THIS FEATURE WILL MOVE ATOP A VERY DRY AIR MASS WITH HIGH
PRESSURE...AND THUS...LITTLE MOISTURE WILL BE AVAILABLE FOR STORMS
DESPITE STRONG FORCING WITH A COLD FRONT.
THE NEXT TROUGH WILL DIG SWD OVER THE WRN STATES ON FRI/D5...AND
WILL BEGIN TO MOVE EWD ACROSS THE ROCKIES FRI NIGHT AND INTO SAT
MORNING.
BECAUSE THIS SECOND TROUGH IS ARRIVING RELATIVELY QUICKLY IN THE
WAKE OF THE PREVIOUS TROUGH...THERE WILL BE LITTLE TIME FOR QUALITY
BOUNDARY LAYER MOISTURE TO RETURN NWD AHEAD OF THIS SYSTEM. DESPITE
A SYNOPTICALLY FAVORABLE SETUP FOR WIDESPREAD SEVERE...WITH A
DEEPENING SURFACE LOW OVER THE PLAINS AND AN INTENSE JET MAX
ALOFT...MODELS INDICATE VERY MEAGER INSTABILITY WILL BE PRESENT FOR
THUNDERSTORMS. IN FACT...THE NEW GFS AS WELL AS THE ECMWF SHOW
ALMOST NO INSTABILITY AT ALL OVER THE WARM SECTOR. SO DESPITE VERY
STRONG FORCING AND SHEAR...SEVERE POTENTIAL MAY BE LOW WITH THIS
SYSTEM.
AS THIS SYSTEM DEPARTS ON SAT NIGHT INTO SUN...SOME HIGHER DEWPOINTS
WILL RESIDE ACROSS ERN TX...AND WILL SURGE BACK NWWD AS LOW LEVEL
WARM ADVECTION COMMENCES AHEAD OF ANOTHER WRN TROUGH. THUNDERSTORMS
WILL BE LIKELY IN THIS REGIME FROM TX INTO OK AND KS...BUT
WIDESPREAD SEVERE IS NOT LIKELY.
..JEWELL.. 10/31/2011
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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:
Post a Comment