Comments on the Atlantic [11.09.2004, 1923 UTC]

[DoctorHurricane2003]

S 11.09.2004 [SAT SEP 11 2004]
1923 UTC [02:23 PM CDT]


HURRICANE IVAN (09L)

Ivan is beginning to complete an eyewall replacement cycle that began overnight last night and resulted in winds dropping to 145 and pressure rising to 926 MB. Pressure reported by reconnaissance is back down to 921 MB. Also, as I expected, Ivan is currently positioned just W of Jamica today and is continuing toward the Cayman Islands. Strength forecast: I expect Ivan to recontinue strengthening, and it is very likely that he will reach category 5 status in the very warm waters west of Jamaica...perhaps just before hitting Cuba. After exiting Cuba, I expect a decrease in winds, and perhaps a steady intensity to the coastline. It is difficult to project how any possible shear, dry air, or a trough will effect the intensity of Ivan in the central and northern Gulf of Mexico at the moment...so I will forecast a 5 KT increase just after leaving Cuba, and a steady intensity after that. Position Forecast: As I expected, models are shifting westward again. It is not out of the question that there will be more shifting, but for right now, I am expecting a landfall in NW FL. Please see below for Position and Intesity Forecast:

ADDED AT 1954 UTC: A recent reconnaissance plane is showing that Ivan may be going through a rapid intensification phase. Therefore, the Intensity forecast is changed.

POSITION AND INTENSITY FORECAST AT 1929Z
INITIAL: 18.0 N 79.0 W 145 KT....W OF JAMAICA
NEXT ADVISORY: 18.5 N 79.8 W 145 KT
12 HR: 19.6 N 81.7 W 150 KT...NEAR CAYMAN ISLANDS
24 HR: 20.0 N 83.1 W 160 KT...SOUTH OF ISLE OF YOUTH
36 HR: 22.6 N 84.2 W 125 KT...OFF OF NW CUBA
48 HR: 24.1 N 85.7 W 125 KT
72 HR: 27.2 N 86.8 W 125 KT
96 HR: 30.4 N 86.5 W 125 KT...NEAR FORT WALTON BEACH, FL
120 HR: 34.3 N 84.9 W 75 KT...INLAND OVER NW GA.

NOTE: EYEWALL REPLACEMENT CYCLES AND RAPID INTENSIFICATION PHASES CAN VARY THE INTENSITY BETWEEN 110 KT AND 170 KT AT ANY TIME.

NOTE: THE POSITION FORECASTS MARGIN OF ERROR ARE AS FOLLOWS: 72 HR: 50 NM 96 HR: 100 NM 120 HR: 150 NM.

US GENERAL LANDFALL PROBABILITIES:
GRAND ISLE, LA TO BILOXI, MS: 8%
BILOXI, MS TO PENSACOLA, FL: 16%
PENSACOLA, FL TO PANAMA CITY, FL: 50%
PANAMA CITY, FL TO ST MARKS, FL: 20%
ST MARKS, FL TO TARPON SPRINGS, FL: 6%

***END

[kevin]

Pressure is down to 918 or 914.. not sure which..

[das8929]

Wow 160 kt! Thats over 180 mph!

[OtherHD]

It's 914. The VDM showing 918 is from before the NHC Ivan update.

[kevin]

Thanks OHD! I was wondering which was one was the real deal. Does that represent a 4mb drop inbetween?? (hopes not)