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Hurricane Ivan - Saturday - September 11, 2004 - 9:00 PM




CURRENTLY: Some minor adjustments to projected landfall swath with this update.

Ivan is now a hurricane with the 6th lowest pressure in the Atlantic basin. Last recon had 910 mbs. Max sustained near 165 mph.

Latest satellite presentation shows a very intense hurricane. Symmetric CDO with very intense, cold cloud tops, excellent out flow in all quadrents…although now a tad limited on the NW side. Eye embedded nicely in the CDO…..another 2004 textbook looking hurricane.

An upper level low as seen on latest WV imagery northeast of Ivan is providing perfect ventilation in the form of an excellent outflow jet. This upper level low is pressing southwest as Ivan moves N.W.W. so this ventilation process should continue for a while.

Latest recon is reporting concentric eye walls one at 12 miles and one at 17 miles. Based on this Ivan should hold steady or perhaps slightly increase over the next 6 to 8 hours…then likely back off some.

Ivan has been moving generally W.N.W. today (285-290 degrees) With some westward wobbles at times. Forward speed has been on average 9 mph or so.

On this track Ivan is taking dead aim on Grand Cayman…the island will likely experience the full fury of Ivan starting about 1:00 A.M. Sunday. I'm afraid for the damage reports out of there tomorrow morning. Ivan will likely do catastrophic damage to Grand Cayman overnight and likely to the Isle of Youth by early Monday.

INTENSITY: Ivan will be moving over waters with a high oceanic heat content for the next 36 hours. Shear is forecast nil. Based on this will forecast a 150-170 mph hurricane through early Monday…there will be some fluctuations…caused by eye wall replacement/concentric eye wall cycles.


Getting nervous about this. With Ivan now forecast to take a more leftward track he will be affected little by Cuba and will emerge quite intact over the southeast Gulf of Mexico.

This further westward path will keep Ivan over warmer waters than if he had come into the extreme eastern Gulf. There is a nice pocket of 78-81 degree water over the northeast Gulf of Mexico. It now appears a good possibility Ivan will at best clip the western edge of that cooler water prior to landfall on the FL panhandle.

So, basically we will have to rely on some increased shear starting at about 48 hours. Latest SHIPS is about 115 mph at landfall.

While I certainly don't expect a Cat 5 hurricane at landfall….I will now at least have to leave the door open a crack to allow for the possibility of a low Cat 4 (131 mph)

My best forecast right now would have to be for a major hurricane in the range of 110-130 mph at landfall time…this is up from my last post Friday evening. I really don't anticipate greater than 130 mph….but just can't slam the door on it yet. Hurricanes this season have been over achievers. Ivan will be moving essentially over untouched Gulf waters.

Will have to look at this again in the days ahead. Intensity forecasting at these ranges don't have all that much skill. I do believe it is safe to say Ivan will be a major hurricane at time of U.S. landfall.

Track: Ivan passed just south of Jamaica last night…about 40 miles south. This kept the core of most destructive winds just offshore the island. The south coast was still blasted with gusts to over 100 mph and battered by 20 foot waves. Wind/wave damage was extensive along the south coast and flooding over high terrain was widespread.

All in all Jamaica took a near direct hit…as bad as it was they were spared a catastrophic event.

Ivan has been moving W.N.W (285-290) degrees for the last 12-18 hours at about 9-11 mph. This motion with a slowly increasing northward component should continue for the next 24-36 hours.

This will take Ivan a safe distance south of Little Cayman and Cayman Brac…these two islands could still have gusts to 100 mph and sustained winds of near hurricane force. Wave and swell action will be significant on south facing beaches. Grad Cayman will not be so lucky. Ivan will either pass right over the Island or just south (by no more than 25 miles….at most) off the south coast. Grand Cayman should be prepared to take a direct hit from a Cat 5 hurricane. It will not be a pretty site there come this time tomorrow.

Next stop on Ivan's "Destruction Tour 2004" …the Isle of Youth just to the south of western Cuba. I expect Ivan to pass a short distance (less than 30 miles) to the left of the Isle of Youth….this would put that Island very near the eastern eye wall….any slight wobble to the right and the island takes a direct hit. This track is an adjustment slightly to the left by about 50 miles from what I had out from earlier in the week.

From Ivan's passage near or perhaps over the Isle of Youth is a passage over extreme western Cuba.

Expect a path that will take Ivan across extreme western Cuba emerging near 23N/84W around noon Monday..…again this track is a slight leftward adjustment (by 60 miles) from what I had been forecasting for the last several days.

Once emerging from Cuba expect a turn more NNW and then gradually more North at a forward speed of roughly 9-12 mph. At this point Ivan will begin the final leg of his trans-Atlantic journey.

Will shift my projected landfall swath slightly left with this update…which will increase the threat to the panhandle and all but eliminate the threat to the west coast of Florida.

Expect a landfall somewhere from the AL/FL border eastward to Cedar Key…with greatest threat in the middle of that swath.

My latest track is in 100% agreement with the latest 5:00 P.M. update from TPC.

Models have come into better agreement….and are all now spraying the FL panhandle with a landfall.

Expected timing….later Wednesday afternoon or evening…this mainly due to the fact we now have to wait for Ivan to reach the northern gulf coast and have essentially ruled out a hit further south on the west coast of Florida.

Now, having said all that…residents south of Cedar Key to Tampa should monitor the progress of Ivan but it is looking much, much better for the west coast of Florida. I will likely give an all clear for the area south of Cedar Key sometime tomorrow. I could essentially do that now, but I don't want folks there to totally let down their guard just yet.

IMPORTANT: Residents along the AL coast should also monitor the progress of Ivan in case the "swath" needs to be nudged a little further to the left. If there has been a trend in the models it certainly has been to the left…so you folks along the AL coast…please keep informed as to any possible additional shift west…this is certainly a possibility. Western Atlantic ridge has been forecast stronger and pressing more westward on most of the global model guidance over the last 24 hours. Want to watch this through tomorrow, residents of the AL coast…please stay alert.

The key to where landfall occurs depends on exactly where the bend to the NNW, N and then NNE takes place. A slower, wider turn favors the western edge of my landfall zone…and a faster, sharper turn will take the center in on the eastern edge.

The thing to watch is…does Ivan pass left, right or over the Isle of youth….pass to the left favors western edge of swath…a pass to the right would favor a more eastern panhandle landfall.

To repeat…my forecast is for landfall between the AL/FL border and Cedar Key…with highest risk from roughly Panama City to St. George Island. Again, this may be subject to a slight leftward adjustment tomorrow evening.

Remember, even though the worst weather will be near and to the right of landfall…Ivan has a wide area of Tropical Storm force winds (125-150 miles) and he will affect a large area.

Will try to narrow specific impacts tomorrow evening.

Next update…..9:30 tomorrow evening. If any significant changes are needed there will be an update about 3:00 in the afternoon.


Please refer to official statements from TPC and local weather services offices for official information. Please obey all evacuation orders as issued by local emergency service offices.

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