[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT44 KNHC 142048
TCDAT4
HURRICANE IVAN DISCUSSION NUMBER  50
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT TUE SEP 14 2004

THIS MORNING'S WEAKENING TREND HAS CEASED AND THE OUTER EYEWALL OF
IVAN IS BECOMING BETTER DEFINED.  A NOAA RESEARCH AIRCRAFT REPORTED
A CENTRAL PRESSURE OF 929 MB ALONG WITH SURFACE WINDS OF 115-120 KT
FROM THE STEPPED FREQUENCY MICROWAVE RADIOMETER.  THE INITIAL
INTENSITY WILL BE HELD AT 120 KT.  SATELLITE IMAGERY SHOWS THAT
CIRRUS IS BEGINNING TO EXPAND IN THE NORTHWEST QUADRANT.  IVAN IS
STILL EXPECTED TO PASS OVER A WARM GULF EDDY IN ABOUT 12 TO 24
HOURS...WHICH COULD HELP IVAN TO REGAIN A LITTLE STRENGTH BEFORE
ENCOUNTERING SLIGHTLY COOLER WATERS AND INCREASING SHEAR JUST
BEFORE LANDFALL.  ALTHOUGH THE PRECISE LANDFALL INTENSITY CANNOT BE
CONFIDENTLY FORECAST...IVAN IS EXPECTED TO BE A MAJOR HURRICANE AT
LANDFALL.

THE INITIAL MOTION IS 335/8...SLIGHTLY TO THE RIGHT OF THE PREVIOUS
MOTION...AND THE SHORT TERM MOTION IS ALMOST NORTHWARD. IVAN IS
MOVING AROUND THE PERIPHERY OF THE ATLANTIC SUBTROPICAL RIDGE.
THERE HAS BEEN NO SIGNIFICANT CHANGE MADE TO THE OFFICIAL
FORECAST...WHICH IS IN THE MIDDLE OF A TIGHTLY CLUSTERED GROUPING
OF THE GFS...GFDL...NOGAPS...AND UKMET MODELS. THE ECMWF REMAINS AN
OUTLIER WITH A TRACK ABOUT 100 MILES WEST OF THE CONSENSUS.

THERE IS CONSIDERABLE SPREAD IN THE MODEL FORECASTS AFTER
LANDFALL...AND IT IS POSSIBLE THAT THE REMNANTS OF IVAN WILL MOVE
VERY SLOWLY OR STALL NEAR OR OVER THE APPALACHIANS IN 4 OR 5
DAYS...WHICH WOULD PRODUCE A VERY SERIOUS FLOODING EVENT.

FORECASTER FRANKLIN

FORECAST POSITIONS AND MAX WINDS

INITIAL      14/2100Z 24.2N  86.6W   120 KT
 12HR VT     15/0600Z 25.3N  87.2W   120 KT
 24HR VT     15/1800Z 27.2N  88.0W   125 KT
 36HR VT     16/0600Z 29.3N  88.3W   120 KT
 48HR VT     16/1800Z 31.5N  88.0W    75 KT...INLAND
 72HR VT     17/1800Z 34.5N  86.0W    30 KT...INLAND
 96HR VT     18/1800Z 35.5N  84.5W    20 KT...INLAND
120HR VT     19/1800Z 35.5N  84.5W    20 KT...INLAND


$$This weather bulletin was brought to you by:
www.nashvilleweather.net