DAY48SVR: Nws Storm Prediction Center Norman Ok

ACUS48 KWNS 210958
SWOD48
SPC AC 210958

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0358 AM CST FRI DEC 21 2012

VALID 241200Z - 291200Z

...DISCUSSION...
THE MEDIUM RANGE MODELS BEGIN THE DAY 4 TO 8 PERIOD WITH AN
UPPER-LEVEL TROUGH MOVING FROM THE FOUR CORNERS REGION ON MONDAY/DAY
4 TO THE GREAT PLAINS ON TUESDAY/DAY 5. THE ECMWF AND GFS HAVE
SIMILAR TIMING AND CLOSE-OFF THE SYSTEM OVER THE ARKLATEX ON
TUESDAY. AS THIS OCCURS...THE MODELS STRENGTHEN A PRONOUNCED
LOW-LEVEL JET AND BRING MOISTURE NWD INTO THE LOWER MS VALLEY
TUESDAY AFTERNOON WHERE A THREAT FOR STRONG THUNDERSTORMS COULD
DEVELOP. IF MORE MOISTURE CAN RETURN NWD INTO THE LOWER MS VALLEY ON
TUESDAY THAN IS CURRENTLY FORECAST...A SUBSTANTIAL SEVERE THREAT
COULD DEVELOP TUESDAY AFTERNOON. THE SEVERE THREAT COULD PERSIST EWD
ACROSS THE GULF COAST STATES FROM TUESDAY NIGHT INTO WEDNESDAY AS
THE SYSTEM PROGRESSES ACROSS THE REGION. AT THIS POINT...WILL NOT
ISSUE AN ENHANCED SEVERE THREAT MAINLY DUE TO UNCERTAINTIES
CONCERNING MOISTURE RETURN AND DIFFERENCES IN MODEL SOLUTIONS.

..BROYLES.. 12/21/2012

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.