Thursday, November 22, 2012

DAY48SVR: Nws Storm Prediction Center Norman Ok

ACUS48 KWNS 220941
SWOD48
SPC AC 220940

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0340 AM CST THU NOV 22 2012

VALID 251200Z - 301200Z

...DISCUSSION...
LOW-LEVEL RIDGING...FOLLOWING PASSAGE OF ERN CONUS TROUGH DESCRIBED
IN DAY-3 OUTLOOK...WILL PRECLUDE SUFFICIENT MOISTURE RETURN TO
SUPPORT ORGANIZED SVR UNTIL AT LEAST DAY-5/26TH-27TH. SHORTWAVE
TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY AS QUASISTATIONARY
PERTURBATION OVER SWRN AK -- IS EXPECTED TO PIVOT AROUND DECAYING
GULF OF AK CYCLONE AND EJECT ESEWD FROM NWRN CONUS TO CENTRAL PLAINS
DAYS 4-5. THIS FEATURE WILL CONTRIBUTE TO GEN SYNOPTIC TROUGHING
DAY-5 AS FAR S AS CENTRAL/S TX.

STRENGTHENING DEEP SHEAR...INCREASINGLY MOIST WARM SECTOR...AND
IMPINGING SFC COLD FRONT STILL ARE EXPECTED BY AFTERNOON AND
OVERNIGHT DAY-5...WITH RELATED SFC-BASED CONVECTIVE AREA POSSIBLE
OVER PORTIONS ERN/NERN TX/ARKLATEX REGION...PERHAPS INTO MS DELTA
REGION LATE. MODEL DISCREPANCIES IN AMPLITUDE AND TIMING OF UPPER
PERTURBATION AND RESULTANT LOW-LEVEL FEATURES ARE ACTUALLY GREATER
THAN 24 HOURS AGO...WITH TYPICALLY MOST RELIABLE ECMWF OFFERING
LEAST AMPLIFIED UPPER-LEVEL SOLUTION. THUS...WHILE SVR EVENT STILL
IS POSSIBLE AND SHOULD BE CONSIDERED...CONFIDENCE IS LOWER THAN
BEFORE...AND DOES NOT SUPPORT UNCONDITIONAL 30% AREA ATTM. AFTER
DAY-5...TOO MUCH SPREAD IN ECMWF/SPECTRAL/UKMET/MREF SOLUTIONS IS
EVIDENT TO DRAW ANY SPECIFIC SVR THREAT AREAS.

..EDWARDS.. 11/22/2012

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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: