5pm ADVISORY - 15.2N 39.1W 80MPH FWD SPEED FASTER 15MPH

[Renata]

Isabel is trying to catch up with the trough to take her North?!?


Hurricane Isabel Advisory Number 7


Statement as of 5:00 PM AST on September 07, 2003


...Isabel getting better organized over the open Atlantic...

at 5 PM AST...2100z...the center of Hurricane Isabel was located
near latitude 15.2 north...longitude 39.1 west or about 1510
miles...2430 km...east of the Leeward Islands.

Isabel is moving toward the west-northwest near 15 mph...24 km/hr...
and this general motion is expected to continue for the next 24
hours.

Maximum sustained winds are near 80 mph...130 km/hr...with higher
gusts. Some strengthening is forecast during the next 24 hours and
Isabel could become a category 2 hurricane on Monday.

Hurricane force winds extend outward up to 30 miles... 45 km...
from the center...and tropical storm force winds extend outward up
to 90 miles...150 km.

The estimated minimum central pressure is 984 mb...29.06 inches.

Repeating the 5 PM AST position...15.2 N... 39.1 W. Movement
toward...west-northwest near 15 mph. Maximum sustained
winds... 80 mph. Minimum central pressure... 984 mb.

The next advisory will be issued by the National Hurricane Center
at 11 PM AST.

Forecaster Stewart

[rob8303]

Hate to bring bad news Renata but NHC discussion is VERY, VERY, VERY ominous. Here it is:
THE ALLEGED EYE OF ISABEL PASSED OVER BUOY 13008 LOCATED AT 15N 38W
BETWEEN 14-15Z. THE BUOY REPORTED 37 KT AND 24 KT NORTHEAST WINDS
...TO THE SOUTH OF ALL THE SATELLITE CENTER POSITIONS. THESE WIND
REPORTS SUGGEST THAT THE ACTUAL CENTER IS FARTHER SOUTH NEAR THE
SOUTHERN PORTION OF THE EYE FEATURE...AS MENTIONED IN THE PREVIOUS
DISCUSSION. DURING THE PAST 6 HOURS...THE EYE FEATURE...OVERALL
CONVECTIVE PATTERN...AND OUTFLOW PATTERN HAVE CONTINUED TO IMPROVE.
THE INITIAL INTENSITY OF 70 KT IS BASED ON SATELLITE INTENSITY
ESTIMATES OF 65 KT FROM TAFB AND SAB...AND 77 KT FROM AFWA.

THE INITIAL MOTION ESTIMATE IS 295/13. THE INITIAL POSITION REMAINS
ABOUT 24 NMI SOUTH OF THE SATELLITE POSITIONS. THE 12Z GLOBAL
MODELS ARE IN EVEN BETTER AGREEMENT NOW ON KEEPING AT LEAST A
MODERATE SUBTROPICAL RIDGE NORTH OF ISABEL ALONG 32N LATITUDE
THROUGHOUT THE FORECAST PERIOD...AND EVEN BUILD IT WESTWARD ACROSS
THE BAHAMAS AND FLORIDA. THIS SHOULD KEEP ISABEL MOVING
WEST-NORTHWESTWARD THROUGH 48-72 HOURS...WITH A GRADUAL WESTWARD
MOTION DEVELOPING AFTER THAT. THE PREVIOUS FORECAST TRACK WAS ONLY
SHIFTED SLIGHTLY NORTHWARD AND SLOWED A LITTLE AFTER 72 HOURS...
WHICH IS CONSISTENT WITH THE GLOBAL MODEL CONSENSUS.

ISABEL CURRENTLY HAS A VERY IMPRESSIVE OUTFLOW PATTERN AND...
UNFORTUNATELY...THE GLOBAL MODELS ARE FORECASTING IT TO BECOME EVEN
BETTER. BY 36-48 HOURS... ALL OF THE GLOBAL MODELS EXCEPT THE UKMET
ARE FORECASTING MORE THAN 50 KT OF OUTFLOW ON THE WEST SIDE OF
ISABEL BEING DRAWN INTO AN UPPER-LEVEL LOW LOCATED JUST NORTHEAST
OF THE LEEWARD ISLANDS. A PATTERN LIKE THAT CAN OFTENTIMES LEAD TO
RAPID OR EXPLOSIVE DEEPENING. THE SHIPS INTENSITY MODEL BRINGS
ISABEL UP TO 97 KT IN 60 HOURS...BUT THE OFFICIAL FORECAST IS A
LITTLE HIGHER SINCE SHIPS WAS LOW/SLOW WITH THE INTENSIFICATION OF
FABIAN. THE INTENSITY WAS LEVELED OFF AFTER 48 HOURS SINCE ISABEL
MAY CROSS A POSSIBLE COLD WAKE LEFT BEHIND BY HURRICANE FABIAN.

FORECASTER STEWART

FORECAST POSITIONS AND MAX WINDS

INITIAL 07/2100Z 15.2N 39.1W 70 KT
12HR VT 08/0600Z 15.8N 40.5W 75 KT
24HR VT 08/1800Z 16.5N 42.8W 85 KT
36HR VT 09/0600Z 17.2N 45.2W 95 KT
48HR VT 09/1800Z 18.0N 47.7W 100 KT
72HR VT 10/1800Z 19.0N 52.0W 100 KT
96HR VT 11/1800Z 19.5N 55.5W 100 KT
120HR VT 12/1800Z 19.5N 60.0W 100 KT

[Renata]

Hate to bring bad news Renata but NHC discussion is VERY, VERY, VERY ominous. Here it is: ....

Hi Rob,

This isn't bad news. The fact that it is not on a true 270 is good news. A 295 degree or 317 as I thought is even better because it is lifting more northward (though I understand the point on the buoy measurement - means that the "alleged" center is more like 14N or just under).

The bad news is that the latest model run is showing a SW component and the discussion from Puerto Rico Weather Service (http://www.srh.noaa.gov/data/JSJ/AFDSJU) explains the building ridge and thus give an explaination as to why models think it will turn southward of due west.

I have an ill feeling that we are dealing with something that is already a category three hurricane because it seems to be creating its own environment.