HENRI #18 - DISCUSSION

[AussieMark]

000
WTNT42 KNHC 080237
TCDAT2
TROPICAL DEPRESSION HENRI DISCUSSION NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT SUN SEP 07 2003

SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE HENRI IS
INTERACTING WITH AN OLD FRONTAL SYSTEM OVER THE SOUTHEASTERN UNITED
STATES...WITH COLD AIR ENTERING THE WESTERN AND SOUTHERN SIDES OF
THE CIRCULATION. THE CYCLONE IS STILL PRODUCING BURSTS OF
CONVECTION EAST AND NORTH OF THE BROAD CENTER...SO IT WILL REMAIN A
30 KT TROPICAL DEPRESSION AT THIS TIME. HOWEVER...WITH THE CURRENT
TRENDS...AN INCREASINGLY BAROCLINIC ENVIRONMENT...AND MORE COLD AIR
FORECAST TO ENTER THE SYSTEM AFTER 36 HR...THE CYCLONE IS NOW
FORECAST TO BECOME AN EXTRATROPICAL GALE IN 12-24 HR RATHER THAN
CONTINUE AS A TROPICAL CYCLONE. THIS MARKS A SIGNIFICANT SHIFT IN
PHILOSOPHY FROM THE PREVIOUS FORECAST.

THE INITIAL MOTION IS 055/7. THERE IS LITTLE CHANGE IN THE TRACK
FORECAST PHILOSOPHY FROM THE PREVIOUS ADVISORY. HENRI IS EMBEDDED
IN MID/UPPER-LEVEL SOUTHWESTERLY FLOW AND SHOULD MOVE SLOWLY EAST-
NORTHEASTWARD ALONG THE FRONTAL SYSTEM. THE MOTION MAY SLOW EVEN
MORE AFTER 36-48 HR AS A SURFACE HIGH BUILD IN TO THE NORTH OF THE
CYCLONE. THE FORECAST TRACK IS BASICALLY AN UPDATE OF THE PREVIOUS
PACKAGE.

FORECASTER BEVEN

FORECAST POSITIONS AND MAX WINDS

INITIAL 08/0300Z 31.9N 76.7W 30 KT
12HR VT 08/1200Z 32.5N 75.8W 35 KT...BECOMING EXTRATROPICAL
24HR VT 09/0000Z 33.6N 74.2W 40 KT...EXTRATROPICAL
36HR VT 09/1200Z 34.3N 72.7W 40 KT...EXTRATROPICAL
48HR VT 10/0000Z 34.7N 71.1W 35 KT...EXTRATROPICAL
72HR VT 11/0000Z 35.0N 69.0W 30 KT...EXTRATROPICAL
96HR VT 12/0000Z 35.0N 68.0W 30 KT...EXTRATROPICAL
120HR VT 13/0000Z 35.0N 67.5W 25 KT...EXTRATROPICAL