11 PM ADVISORY OUT -- DUE WEST 60 MPH AT 10MPH

[Renata]

Estimated minimum central pressure is 997 mb...

13.4 north...longitude 36.1 west

moving toward the west near 10 mph...

Tropical storm force winds extend outward up to 85 miles

======
Satellite imagery during the evening shows that Isabel has a
well-defined curved convective band with tops colder than -80c.
The cirrus outflow is excellent over the south semicircle and fair
to good elsewhere. Satellite intensity estimates are 55 kt from
TAFB and SAB...and 45 kt from AFWA. The initial intensity is
raised to 50 kt for this advisory.
The initial motion is 270/09. Water vapor imagery indicates that
Isabel is south of a mid/upper-level ridge...with an upper-level
low centered near 26n46w. Large-scale models suggest that this low
will create enough weakness in the ridge to allow Isabel to
gradually turn to a west-northwestward course during the next 24-48
hr...and continue that general motion through day 5. NHC track
guidance agrees with this scenario. Since some models showed
somewhat of a northward bias when Fabian was in this area...the
official forecast will lean toward the south side of the guidance.
It is also nudged just a little south of the previous track.
Isabel seems to have all the ingredients to strengthen
significantly...a large cyclonic envelope...good convective
structure...cold cloud tops...and favorable outflow and vertical
shear. The SHIPS model takes the storm to 80 kt in 60 hr and then
stops intensification for reasons not readily apparent. The GFDL
makes Isabel a 90 kt hurricane in 120 hr. The intensity forecast
will show the intensity leveling off at 80 kt in agreement with the
SHIPS model. However...it would not be a surprise to see Isabel
strengthen faster and more than currently forecast.

Forecaster Beven

forecast positions and Max winds

initial 07/0300z 13.4n 36.1w 50 kt
12hr VT 07/1200z 13.4n 37.4w 60 kt
24hr VT 08/0000z 13.8n 39.4w 65 kt
36hr VT 08/1200z 14.7n 41.8w 70 kt
48hr VT 09/0000z 15.6n 44.4w 75 kt
72hr VT 10/0000z 17.0n 49.4w 80 kt
96hr VT 11/0000z 18.0n 54.5w 80 kt
120hr VT 12/0000z 18.5n 59.0w 80 kt

[Josephine96]

I said.. 65 mph and 994... moving west at 12 lol

[Renata]

My forecast was wrong!

[weatherlover427]

Good call J96 Looks like she is a buff one

[Renata]

The acid test is in the next 36 hours and the question is: "To turn or not to turn, that is the question". (Sorry Shakespeare).

Will that low cause a weakness in the ridge strong enough to turn Isabel??

Let's wait and see.

[The_Cycloman_PR]

forecast positions and Max winds

initial 07/0300z 13.4n 36.1w 50 kt
12hr VT 07/1200z 13.4n 37.4w 60 kt
24hr VT 08/0000z 13.8n 39.4w 65 kt
36hr VT 08/1200z 14.7n 41.8w 70 kt
48hr VT 09/0000z 15.6n 44.4w 75 kt
72hr VT 10/0000z 17.0n 49.4w 80 kt
96hr VT 11/0000z 18.0n 54.5w 80 kt
120hr VT 12/0000z 18.5n 59.0w 80 kt[/b][/color]

Please note that the NHC forecast positions have been slowly moved to the west as each bulletin comes out...

Here are the past ones...

5 pm...
FORECAST POSITIONS AND MAX WINDS

INITIAL 06/2100Z 13.4N 35.4W 45 KT
12HR VT 07/0600Z 13.4N 36.8W 50 KT
24HR VT 07/1800Z 13.5N 38.5W 60 KT
36HR VT 08/0600Z 14.5N 40.5W 65 KT
48HR VT 08/1800Z 15.5N 43.0W 70 KT
72HR VT 09/1800Z 17.0N 48.5W 75 KT
96HR VT 10/1800Z 18.0N 53.5W 75 KT
120HR VT 11/1800Z 18.5N 58.0W 75 KT

11 am...
FORECAST POSITIONS AND MAX WINDS

INITIAL 06/1500Z 13.6N 34.5W 35 KT
12HR VT 07/0000Z 13.7N 36.4W 40 KT
24HR VT 07/1200Z 14.0N 39.0W 45 KT
36HR VT 08/0000Z 14.5N 41.5W 55 KT
48HR VT 08/1200Z 15.0N 44.0W 65 KT
72HR VT 09/1200Z 16.0N 48.0W 65 KT
96HR VT 10/1200Z 17.0N 51.9W 65 KT
120HR VT 11/1200Z 18.0N 56.5W 65 KT


and 9 am...
FORECAST POSITIONS AND MAX WINDS

INITIAL 06/1300Z 14.0N 34.0W 35 KT
12HR VT 06/1800Z 14.0N 35.0W 40 KT
24HR VT 07/0600Z 14.0N 37.5W 45 KT
36HR VT 07/1800Z 14.5N 40.0W 55 KT
48HR VT 08/0600Z 15.0N 42.5W 65 KT
72HR VT 09/0600Z 15.5N 46.5W 65 KT
96HR VT 10/0600Z 16.5N 50.0W 65 KT
120HR VT 11/0600Z 17.5N 54.5W 65 KT

If Isabel continue moving westward I think they will keep adjusting it more westward. It will depend of how the ridge to the north of it behave but if it remains strong and well placed then Isabel could keep moving westward for a longer time and get too close for comfort. I really hope not!

Cycloman.

By the way...It look's awesome tonight!

[wx247]

I agree Cycloman. That needs to be carefully watched. The timing of the turn will be extremely crucial.

[The_Cycloman_PR]

Agree wx247! Time will be crucial on thisone

Somebody please shot an arrow to the ridge north of Isabel and explode it! I really want Isabel to go out to sea! If it get close to us, I think it would be as strong or even stronger than Fabian when it was near 55W. I really think thisone could reach Major+ status before it reach the 60"sW:(

Cycloman.

[wow]

Almost looks a little stationary for a moment there...

http://wwwghcc.msfc.nasa.gov/GOES/globalir.html (select animation & set # of frames, then click on Isabelle. this runs in 30min intervals)