[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT44 KNHC 150233
TCDAT4
HURRICANE IVAN DISCUSSION NUMBER  51
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT TUE SEP 14 2004

OBSERVATIONS FROM AIR FORCE AND NOAA RECONNAISSANCE AIRCRAFT
INDICATE THAT IVAN IS MAINTAINING 120 KT...CAT. 4...INTENSITY.
WATER VAPOR IMAGERY AND GPS DROPSONDE OBSERVATIONS FROM THE NOAA
G-IV JET INDICATE STRONG UPPER-LEVEL OUTFLOW AS WELL.  THERE IS THE
POSSIBILITY THAT THE HURRICANE CORE WILL PASS OVER SOME HIGHER
HEAT CONTENT WATERS DURING THE NEXT 24 HOURS...SO SOME
STRENGTHENING IS POSSIBLE ON WEDNESDAY.  AS THE HURRICANE NEARS THE
COAST...A SHALLOWER LAYER OF WARM WATERS AND SOME INCREASE IN
VERTICAL SHEAR COULD CAUSE SLIGHT WEAKENING.  HOWEVER...WE
EMPHASIZE THAT IVAN IS EXPECTED TO BE A VERY POWERFUL AND DANGEROUS
HURRICANE AT LANDFALL.

INITIAL MOTION IS A LITTLE FASTER...NOW 340/10.  THE TRACK FORECAST
REASONING AND NUMERICAL GUIDANCE REMAINS BASICALLY UNCHANGED FROM
THE PREVIOUS PACKAGE.  IVAN IS BEING STEERED MAINLY BY THE FLOW ON
THE WEST SIDE OF A MID-TROPOSPHERIC RIDGE.  THERE IS GOOD AGREEMENT
AMONGST THE GFDL...GFS...UKMET...NOGAPS...AND GFDN MODELS ON THE
PREDICTED TRACK FOR THE NEXT 36 HOURS.  THE CURRENT OFFICIAL
FORECAST TRACK FOLLOWS A CONSENSUS OF THE AFOREMENTIONED 5
DYNAMICAL MODELS...AND IS SIMILAR TO THE FORECAST FROM THE PREVIOUS
ADVISORY.  LATE IN THE FORECAST PERIOD...GLOBAL MODEL GUIDANCE
SUGGESTS THAT IVAN WILL NOT GET PICKED UP BY THE WESTERLIES BUT
RATHER WILL STALL OR MOVE ERRATICALLY NEAR THE SOUTHERN
APPALACHIANS.  SO THIS OFFICIAL FORECAST...LIKE THE PREVIOUS ONE...
SHOWS NO MOVEMENT AT DAYS 4 AND 5.

SINCE IVAN IS SO LARGE AND INTENSE...IT HAS THE POTENTIAL TO CARRY
STRONG AND DAMAGING WINDS WELL INLAND ALONG ITS PATH.  NOTE THAT
THE OFFICIAL FORECAST INDICATES THAT THE SYSTEM WILL STILL BE AT
HURRICANE STRENGTH 12 HOURS AFTER LANDFALL.

FORECASTER PASCH

FORECAST POSITIONS AND MAX WINDS

INITIAL      15/0300Z 25.1N  87.2W   120 KT
 12HR VT     15/1200Z 26.6N  87.8W   125 KT
 24HR VT     16/0000Z 28.6N  88.2W   125 KT
 36HR VT     16/1200Z 30.6N  88.2W   120 KT...INLAND
 48HR VT     17/0000Z 32.6N  87.6W    70 KT...INLAND
 72HR VT     18/0000Z 35.0N  85.5W    30 KT...INLAND
 96HR VT     19/0000Z 35.5N  85.0W    20 KT...INLAND
120HR VT     20/0000Z 35.5N  85.0W    20 KT...INLAND


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