TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
147 PM EST TUE NOV 04 2008

FINAL

DISCUSSION FROM NOV 04/0000 UTC. MODELS MAINTAIN GOOD CONTINUITY
WITH PREVIOUS RUN ON THE EVOLUTION OF THE MID/UPPER LEVEL FLOW
OVER THE CARIBBEAN BASIN. SOME ADJUSTMENTS WERE NOTED AT LOW
LEVELS ON HOW THEY RESOLVE AN EVOLVING TROPICAL CYCLONE. AS IT
PERTAINS TO THIS FEATURE...THE GFS MODEL NOW AGREES WITH THE OTHER
MODELS ON POSSIBILITY OF A TROPICAL CYCLONE FORMING OVER THE
SOUTHERN/WESTERN CARIBBEAN. BUT THEY CONTINUE TO DIVERGE ON HOW
FAST IT IS GOING TO FORM/MOVE. THE ECMWF REMAINS THE
SLOWEST/STRONGEST...WHILE THE GFS IS THE FASTEST/WEAKEST. THE
REGIONAL NAM FOLLOWS A SIMILAR TRACK TO THE ECMWF... BUT AFTER
48-54 HRS IT TENDS TO SPEED UP. THE UKMET TILTS THE SCALE IN FAVOR
OF THE SLOWER ECMWF SOLUTION.
http://www.srh.noaa.gov/data/WBC/PMDCA

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
217 PM EST TUE NOV 04 2008

VALID 12Z FRI NOV 07 2008 - 12Z TUE NOV 11 2008

TELECONNECTIONS WITH A NEGATIVE ANOMALY OVER SOUTHWEST ALASKA
FAVOR A SPLIT FLOW OVER NORTH AMERICA...WITH TROUGHING ACROSS THE
SOUTHWEST AND A NORTHERN STREAM TROUGH IN EASTERN CANADA AND NEW
ENGLAND. THE MODELS CONVERGE UPON THIS SCENARIO...BUT DIFFER
SIGNIFICANTLY ON THE STRENGTH OF SYSTEMS EMBEDDED WITHIN BOTH THE
NORTHERN AND SOUTHERN STREAM FLOW. THE DEEP CYCLONE MOVING
THROUGH THE WESTERN ATLANTIC EARLY IN THE PERIOD CONTINUES TO BE A
ROGUE ELEMENT IN THE FORECAST AS WELL.
...THE SYSTEM IN THE WESTERN ATLANTIC EARLY IN THE PERIOD SHOULD KICK
OUT NORTHEAST AHEAD OF THE DEEP CYCLONE MOVING INTO THE GREAT
LAKES. CONSIDERING THE DETERMINISTIC AND ENSEMBLE SPREAD AS WELL
AS THE ABOVE LOGIC...THE CANADIAN IS FAVORED EARLY ON WITH THIS
SYSTEM AS THE 00Z GFS WAS ON THE FAST SIDE OF THE SPREAD...WHILE
THE 00Z ECMWF WAS ON THE RIGHT HAND/SOUTH SIDE OF THE ENSEMBLE
ENVELOPE.
http://www.srh.noaa.gov/data/WBC/PMDEPD