SWOD48
SPC AC 170829
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0329 AM CDT SAT MAY 17 2008
VALID 201200Z - 251200Z
...DISCUSSION...
GFS AND ECMWF IN SLIGHTLY BETTER AGREEMENT THIS FORECAST...THOUGH
LARGE DIFFERENCES CONTINUE TO EXIST BETWEEN THE TWO MODELS. BOTH
MODELS FORECAST SIGNIFICANT AMPLIFICATION OF THE UPPER PATTERN
THROUGH THE FORECAST PERIOD...WITH A LARGE TROUGH EVOLVING OVER THE
WEST AND A SECOND TROUGH PERSISTING ACROSS THE EAST...SEPARATED BY A
SHARP RIDGE.
THE ECMWF REMAINS MUCH MORE PERSISTENT WITH THE ERN FEATURE...AND
THUS MAINTAINS A RIDGE OVER THE CENTRAL U.S. BETWEEN TWO
HIGHLY-AMPLIFIED TROUGHS -- A CLASSIC OMEGA BLOCK.
MEANWHILE...THE GFS IS MUCH WEAKER WITH THE ERN TROUGH/UPPER
LOW...ALLOWING THIS FEATURE TO PROGRESS SLOWLY EWD INTO THE WRN
ATLANTIC. AS THIS OCCURS...THE CENTRAL U.S. RIDGE SHIFTS SLOWLY EWD
INTO THE ERN U.S. THROUGH THE END OF THE PERIOD...THUS FACILITATING
THE EVENTUAL DEAMPLIFICATION OF THE LARGE WRN U.S. TROUGH BY DAY 8.
WHILE BOTH MODELS DEPICT DEEP SLY FLOW ACROSS THE CENTRAL U.S.
THROUGH THE FIRST HALF OF THE PERIOD -- AND THUS A RETURN OF GULF
MOISTURE WHICH SUGGESTS AN INCREASE IN CONVECTIVE POTENTIAL WITH
TIME...TIMING AND LOCATION OF ANY SEVERE EVENTS REMAINS DIFFICULT TO
DISCERN AT THIS TIME. THUS...WILL NOT ATTEMPT TO OUTLOOK ANY THREAT
AREAS ATTM.
..GOSS.. 05/17/2008
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment