Monday, March 16, 2009

DAY48SVR: Nws Storm Prediction Center Norman Ok

ACUS48 KWNS 160817
SWOD48
SPC AC 160817

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0317 AM CDT MON MAR 16 2009

VALID 191200Z - 241200Z

...DISCUSSION...
MODELS CONTINUE TO FORECAST THAT A MID-LEVEL TROUGH WILL
EXPAND/PROGRESS EWD ACROSS THE ERN U.S. EARLY IN THE
PERIOD...FOLLOWED BY A SECOND TROUGH MOVING INLAND ACROSS THE WRN
CONUS FROM THE ERN PACIFIC.

AS THIS TROUGH APPROACHES AND THE UPPER PATTERN AMPLIFIES...AND
LOW-LEVEL FLOW TURNS SLY ACROSS THE CENTRAL CONUS AHEAD OF HIGH
PLAINS LEE TROUGHING...A SLOW INCREASE IN SEVERE POTENTIAL CONTINUES
TO APPEAR POSSIBLE LATE IN THE PERIOD.

HOWEVER...THE GFS AND ECMWF DIFFER SIGNIFICANTLY IN HANDLING THE
EVOLUTION OF THE WRN TROUGH. THE ECMWF MAINTAINS AN AMPLIFYING
TROUGH OVER THE INTERMOUNTAIN WEST THROUGH THE END OF THE
PERIOD...WHILE THE GFS EJECTS THE TROUGH NEWD INTO THE CENTRAL/NRN
PLAINS DAY 8. THESE UNCERTAINTIES PRECLUDE THE INTRODUCTION OF A
THREAT AREA THIS FORECAST.

..GOSS.. 03/16/2009

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