MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
100 AM EDT SAT SEP 06 2008

MODEL INITIALIZATION...

...SEE NOUS42 KWNO ADMNFD FOR STATUS OF UPPER AIR INGEST...

IKE...
A CROSS-SECTION OF THE ECMWF LOOKING AT POTENTIAL VORTICITY SHOWS
A TYPICAL HURRICANE. HOWEVER...THE GFS APPEARS TO HAVE THE SYSTEM TOO TILTED/SHALLOW AT INITIALIZATION...WHICH DOES NOT IMPROVE APPRECIABLY EVEN 108 HOURS INTO ITS FORECAST. THIS DEPTH PROBLEM COULD IMPACT ITS TRACK LATE IN THE SHORT RANGE...AND INTO THE MEDIUM RANGE PERIOD.

IKE...
THE NAM HAS TRENDED SOUTHWEST WITH THIS SYSTEM OVER ITS PAST DAY OF RUNS. THE ECMWF IS IN THE MIDDLE OF THE SPREAD SEEN DURING ITS PAST COUPLE DAYS OF RUNS. THE GFS HAS TRENDED WEST-SOUTHWEST WITH THIS SYSTEM OVER ITS PAST 36 HOURS OF RUNS...BUT SOME OF THIS COULD BE RELATED TO THE PROBLEMS WITH ITS INITIAL DEPTH NOTED IN THE INITIALIZATION SECTION ABOVE.

MODEL DIFFERENCES AND PREFERENCES...

IKE...
THE CANADIAN IS THE MOST NORTHEAST WITH THIS SYSTEM...WHILE THE GFS/ECMWF MOVE THE SYSTEM INTO CENTRAL CUBA LATE SUNDAY. MODEL TRENDS SUGGEST AN ECMWF-LIKE SOLUTION WOULD BE PREFERRED DUE TO
ITS BETTER CONTINUITY AND THE GFS/NAM TRENDS TOWARDS THIS
SOLUTION. HOWEVER...THE GFS HAS PROBLEMS WITH ITS INITIALIZATION THAT COULD BE CONTAMINATING ITS FORECAST SOLUTION EARLY NEXT WEEK. A FASTER RENDITION OF THE 00Z CANADIAN...OR NORTHWARD VERSION OF THE FS/ECMWF...WOULD BE MOST SIMILAR TO THE ONGOING NHC FORECAST