EXTENDED FCST DISC VALID MON SEP 23 2002 THRU FRI SEP 27 2002
HYDROMETEOROLOGICAL PREDICTION CENTER/NCEP/NWS
334 PM EDT FRI SEP 20 2002

...MODEL DISCUSSION...

THE 500MB LONGWAVE PATTERN REMAINS A KEY PLAYER IN DETERMINING
WHAT EFFECT HURRICANE "ISIDORE" MIGHT EVENTUALLY HAVE ON THE
MAINLAND OF THE LOWER 48 STATES. ABOVE AVERAGE UNCERTAINTY
CONTINUES WITH THIS STORM RIGHT INTO DAY 7. STRONG POSITIVE HEIGHT
ANOMALIES NE OF NEWFOUNDLAND AND NEAR THE W COAST OF NOAM WILL
SANDWICH A BROAD N-S NEGATIVE HEIGHT ANOMALY OVER S CENTRAL
CANADA AND THE N CENTRAL CONUS DAYS 3-5. NEGATIVE HEIGHT ANOMALIES
WILL SPREAD EWD TO THE E COAST IN THE DAY 5-8 PERIOD WITH VERY CHILLY
AIR OVER THE GREAT LAKES.

THE MEAN PATTERN STILL FAVORS "ISIDORE" EVENTUALLY BEING PICKED UP
AND PULLED N INTO THE SERN STATES. 00Z/19 MODEL RUNS WERE SPLIT ON ITS
TRACK IN THE DAY 4-7 TIME FRAME. THIS MORNING I THOUGHT THAT THE
AVN/ECMWF/UKMET MIGHT BE TRACKING ISIDORE SO FAR S INTO THE BAY OF
CAMPECHE THAT IT WOULD NOT INTERACT WITH ANY SHORTWAVES MOVING
THRU THE BASE OF THE CENTRAL CONUS TROF. IN THIS MORNINGS RELEASE...I
DECIDED TO GO WITH THE AVN...EXCEPT IN THE GULF OF MEXICO AND
ALONG/OFFSHORE THE ATLANTIC SEABOARD. THE NEW 12Z AVN DID NOT
CHANGE THAT REASONING. THE 00Z/19 CANADIAN/GFDL/NOGAPS AIMED
HURRICANE "ISIDORE" TOWARDS THE CENTRAL/ERN GULF COAST AROUND DAY
5. HOWEVER...THE 12Z/19 CANADIAN MODEL BACKED OFF FROM ITS 00Z RUN AND
NOW TRACKS "ISIDORE" FARTHER WWD INTO THE GULF CLOSER TO THE TRACK
OF THE AVN MODEL.

AFTER MY NOON CONFERENCE CALL WITH THE NHC...MY LOW-CONFIDENCE
TRACK OF "ISADORE" THRU DAY 7 IS FARTHER S AND W THAN IN MY EARLY
RELEASE. I HAVE NOT GIVEN UP ON THE IDEA THAT THE STORM WILL BE
EVENTUALLY PICKED UP AND PULLED NWD...BUT IT MAY TAKE LONGER THAN I
EARLIER THOUGHT.

WE CONTINUE TO DISCOUNT A SUBTROPICAL SYS DEVELOPED BY THE LATEST
AVN RUNS VCNTY OF THE BAHAMAS DAY 3...THEN MOVED NNEWD OFFSHORE
THEREAFTER.