000
WTNT44 KNHC 252052
TCDAT4
 
TROPICAL STORM DEBBY DISCUSSION NUMBER  10
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL042012
400 PM CDT MON JUN 25 2012
 
SATELLITE IMAGERY INDICATES THAT DEBBY HAS CHANGED LITTLE IN
ORGANIZATION TODAY. THE CENTER OF THE CYCLONE IS A LITTLE HARDER TO
LOCATE...WITH AT LEAST A COUPLE OF SMALL VORTICES ROTATING AROUND A
MEAN CENTER. THERE HAD BEEN VIRTUALLY NO CONVECTION ASSOCIATED WITH
THE CENTER OF THE CYCLONE EITHER...BUT A BURST OF DEEP CONVECTION
HAS RECENTLY FORMED OVER LAND TO THE NORTH OF THE CENTER. EARLIER
AIRCRAFT DATA SHOWED PEAK FLIGHT-LEVEL WINDS OF 57 KT AT 850MB...
WITH MAXIMUM SFMR VALUES AROUND 40 KT. GIVEN THESE DATA AND THE
LACK OF STRUCTURAL CHANGES TO THE CYCLONE...THE INITIAL INTENSITY
REMAINS 40 KT.  THE CURRENT STRUCTURE...COMBINED WITH AN INCREASE
IN WESTERLY SHEAR AND ADDITIONAL DRY AIR POSSIBLY WRAPPING INTO THE
STORM CIRCULATION...WOULD SEEM TO PRECLUDE MUCH SHORT-TERM
RE-INTENSIFICATION OF DEBBY...AND THE SHIPS AND LGEM MODELS SHOW NO
APPRECIABLE CHANGE IN STRENGTH PRIOR TO LANDFALL. MARGINALLY
FAVORABLE ENVIRONMENTAL CONDITIONS COULD PROVIDE AN OPPORTUNITY FOR
RE-STRENGTHENING OVER THE WESTERN ATLANTIC AT THE END OF THE
FORECAST PERIOD.
 
A SMOOTHING OF RECENT AIRCRAFT AND SATELLITE FIXES YIELDS A SLOW
NORTHEASTWARD MOTION OF 040/04. LARGE-SCALE MODELS SHOW DEBBY
CONTINUING ON AN EAST-NORTHEASTWARD TO NORTHEASTWARD COURSE OVER
THE NEXT FEW DAYS IN RESPONSE TO AN AMPLIFYING TROUGH OFFSHORE OF
THE U.S. EAST COAST. AS THE WESTERN ATLANTIC TROUGH BEGINS TO LIFT
OUT IN 2-3 DAYS...DEBBY IS EXPECTED TO SLOW DOWN AND BE LEFT BEHIND
OVER THE SOUTHWESTERN ATLANTIC. WITH THE EXCEPTION OF THE GFS
ENSEMBLE MEMBERS...THE MODEL GUIDANCE IS IN BETTER AGREEMENT
OVERALL ON AN EASTWARD TRACK...ALTHOUGH SIGNIFICANT SPEED
DIFFERENCES REMAIN. THE GFS IS CONSIDERABLY SLOWER THAN THE MODEL
CONSENSUS...AND SHOWS DEBBY TAKING FIVE DAYS TO MOVE OFFSHORE THE
FLORIDA ATLANTIC COAST. INTERESTINGLY...THE ECMWF IS NOW ONE OF THE
FASTEST MODELS TO THE EAST. THE NHC OFFICIAL TRACK FORECAST IS NOT
AS FAST AS THE MULTI-MODEL CONSENSUS IN DEFERENCE TO CONTINUITY AND
THE GFS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/2100Z 29.3N  85.1W   40 KT  45 MPH
 12H  26/0600Z 29.4N  84.9W   40 KT  45 MPH
 24H  26/1800Z 29.5N  84.7W   40 KT  45 MPH
 36H  27/0600Z 29.6N  84.4W   40 KT  45 MPH
 48H  27/1800Z 29.7N  83.8W   40 KT  45 MPH
 72H  28/1800Z 29.8N  82.5W   30 KT  35 MPH...INLAND
 96H  29/1800Z 29.8N  81.0W   30 KT  35 MPH
120H  30/1800Z 30.0N  79.0W   35 KT  40 MPH
 
$$
FORECASTER KIMBERLAIN/