This information is provided for informational purposes only and is not intended to be a substitute nor should it be used in place of official information. Please follow and obey orders from local emergency management officials.
Hurricane Ivan - Sunday - September 12, 2004 - 9:00 PM
***IVAN TO ENTER GULF IN 18 OR SO HOURS***
*RESIDENTS FROM ALABAMA TO APALACHICOLA STAY TUNED*
CURRENTLY: Ivan remains a very intense hurricane….bordering on the brink of Cat 5 intensity. Intensity could top out again at 160-165 mph sometime over the next 12-18 hours.
Ivan continues to show all the features of a well developed, intense hurricane on latest satellite pictures.
Ivan has been moving generally W.N.W. today (285-290 degrees) With some westward wobbles at times. Forward speed has been on average 10 mph or so.
Ivan passed just south of Grand Cayman Island (by about 30 miles) late last night and early this morning. While Grand Cayman was spared eye wall passage it was still raked by sustained hurricane force winds with GUSTS over 115 mph. Damage was quite extensive I'm sure.
INTENSITY: Ivan will be moving over waters with a high oceanic heat content for the next 18-24 hours. Shear is forecast nil. Based on this will forecast a 150-165 mph hurricane through early Monday afternoon, there will be some fluctuations…caused by eye wall replacement/concentric eye wall cycles.
INTENSITY BEYOND 24 HOURS - OR AFTER EMERGENCE INTO THE GULF OF MEXICO:
With Ivan now forecast to take a more leftward track he will be not be affected by Cuba and will emerge 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 is now a given that Ivan will miss this pocket of cooler water so we can't hope for that to aid in any weakening trend.
In fact if Ivan remains on course he will pass over a pocket of warmer waters in the east/central gulf.
So, basically we will have to rely on some increased shear starting at about 36 hours. Latest SHIPS is about 125 mph at landfall.
While I certainly don't expect a Cat 5 hurricane at landfall….I have to at least 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 unchanged from my post on Saturday 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 and if shear is weaker than forecast Ivan could over achieve as well.
My best advice….if you live along the AL coast eastward to Apalachicola, FL…use Monday to start taking preliminary preparations for a major hurricane…there is little to no doubt it is coming…it is now becoming a matter of just nailing the exact spots that will take the direct hit. If Ivan does come ashore at 130 mph the storm surge could be in excess of 15 feet (depending on tide cycle) and there are many barrier islands on the western panhandle that could be in the path of that surge. Once again….worst effects will be near and to the right of where the center crosses. Ivan has a large wind field and effects will be rather far reaching….inland wind, tree and power line damage will likely be very extensive.
Ivan has been moving W.N.W (285-290 degrees) for the last 12 hours at about 10 mph. Based on last few satellite and recon fixes it appears the bend more to the NW (300-305 degrees) is now underway.
On this track Ivan will just clip the extreme western tip of Cuba or pass just to the west (not more than 30 miles)..This track will spare the Isle of Youth a direct hit as well as western Cuba….still, winds of Tropical Storm force will extend well to the east over Cuba and the western 1/3 of the Island will still see winds to hurricane force with gusts to near 100 mph on the western ¼ of the island. But again, a catastrophic disaster will be avoided.
This track represents another leftward adjustment by about 100 miles from last night. This will likely be the last westward adjustment since it now appears Ivan is turning more NW.
Once Ivan clears the western tip of Cuba he will enter the Gulf for a final run at land….the Gulf coast of the United States.
Models have continued to shift westward today, with the ECMWF and Canadian Global taking aim at the central coast of LA. NOGAPS is near the mouth of the Mississippi river. The UKMET is near Mobile. The GFDL is just west of Apalachicola. The GFS is near Apalachicola. Latest TPC model suite (00Z) is over the western FL panhandle.
Once Ivan enters the southern Gulf of Mexico expect a general NW, then NNW then North motion up until landfall.
The threat for landfall along the west coast of Florida is over.
Will shift my projected landfall swath slightly left with this update…which will increase the threat to the AL coast and western panhandle.
Expect a landfall somewhere from the MS/AL border eastward Apalachicola Florida. With the area from the AL/FL border east to Panama City FL, in the highest threat zone. The area east of Apalachicola to Cedar is almost an "all clear" zone for landfall…could almost do that now but I'd rather wait another 12 hours or so.
Expected timing….later Wednesday afternoon or evening.
My track is slightly left of the official TPC track.
IMPORTANT: Residents west of Mobile Bay to near New Orleans should closely monitor future updates in the event another westward adjustment is needed.
The key to where exactly landfall occurs depends on exactly where the bend to the NNW, North 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.
To repeat…my forecast is for landfall between MS/AL border eastward to near Apalachicola Florida…with highest risk from near Mobile Bay eastward to Destin, Florida.
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.
THIS INFORMATION IS FOR INFORMATIONAL PURPOSES ONLY. IT IS NOT A SUBSTITUTE FOR OFFICIAL INFORMATION.
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.