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 - Monday - September 13, 2004 - 9:30 PM
***IVAN ENTERS THE GULF OF MEXICO***
*NEXT STOP….GULF COAST - HURRICANE WATCHES SHORTLY*
CURRENTLY: Ivan remains a very intense hurricane….Ivan is now undergoing his final intensification cycle. Winds could pop up to 165-170 mph over the next 6-8 hours. After that gradually increasing shear will start to gradually weaken Ivan. Latest pressure is 914 mbs…could drop down to 905 or so in the next 6-8 hours…then slowly start to rise.
Ivan continues to show all the features of a well developed, intense hurricane on latest satellite pictures.
Ivan has been moving generally N.W. today (315 degrees) With some slight wobbles to the right at times. Forward speed has been on average 10 mph or so.
Ivan is making his closest approach to Cuba right now.…the eastern eye wall is ravaging the extreme western tip of Cuba…with the center passing no more than 10 miles off the western tip of Cuba. Sustained winds of 125 mph with gusts to 160 mph have been reported over extreme western Cuba. Damage over the western ¼ of Cuba will be severe.
Looking back…the position I gave last Tuesday evening (6 days ago) was for Ivan to be near 23N/83W Sunday afternoon. That was 24 hours fast and off by roughly 120 miles…so we have an error of 120 miles on a six day forecast. I also stated last Tuesday that Ivan was taking aim on the Gulf coast from the MS/AL border east to Cedar Key.
Yes, it is true that I was aiming more to the east of that swath mid to late last week…and have had to make adjustments leftward over the past few days….My forecast from last Wednesday called for landfall somewhere between the AL/FL border to near Tampa….in reality the final landfall will be very near the western end of that swath and about 24 hours later than forecast.
I bring all this up because I've gotten a few e-mails about flip-flopping in the forecast. In reality I have been following the trend to shift westward and have never had to go back the other way. So, I look at it as a refinement in the forecast as landfall gets closer. Flip-flopping implies I've been going back and forth and that has not been the case at all. So, we have a six day forecast with a 120 mile error and depending on where exact landfall takes place we could have an 8 day forecast with a roughly 325 mile error.
Now back to our regularly scheduled update.
INTENSITY: As Ivan starts to track through the Gulf the waters are warm and Ivan will passing over an even warmer eddy of water bounded by 86-88W and 27-28.5N…water temps here are bordering in 31C based on latest NOAA/NESDIS analysis. A much cooler pocket of water (27C) lies east of 86W….but Ivan will miss that.
So, SST wise Ivan will have a significant fuel source.
Thus, we are faced with a situation where we are counting on gradually increasing shear to weaken Ivan over the next 72 hours. There is no doubt that the shear will increase, especially in the 12 hours before landfall.
Ivan is a large, well developed hurricane with excellent outflow. As a result of this he may be able to battle off the shear as his circulation tries to dominate the gulf and quite literally shove the shear out of his way.
Make no mistake…I fully expect to weaken starting in the next 8-10 hours. It remains to be seen however how fast that weakening takes place. The bulk of the weakening could come in the 12 hours prior to landfall as the westerlies start to really impinge on the circulation.
Bottom line from all this….expect Ivan to be a major hurricane at landfall….115 mph+. My official forecast will call for 125 mph at landfall…give or take a little up or down (+/- 10 mph either way).
This is a major hurricane and is capable of producing significant damage. The area of the Gulf coast Ivan is forecast to affect is very prone to storm surge. Depending on the tide cycle (high or low) storm surge could be in the vicinity of 15 feet….this will make for quite the mess along the barrier islands.
Latest 00Z SHIPS is about 110 kts (125 mph) at time of landfall…really can't find anything to disagree with there.
Hurricane watches will likely be posted not later than with the 5:00 A.M. TPC advisory Tuesday.
If you are asked to evacuate….DO IT !
Will continue with the forecast I issued at 3:00 this afternoon.
Now forecasting landfall somewhere between Biloxi, Ms and Ft. Walton Beach, FL….with the highest threat between Mobile, AL and Pensacola, FL.
Timing of expected landfall….Wednesday night/Thursday morning…between roughly 9:00 p.m. Wednesday and 9:00 a.m. Thursday…or about 48-60 hours from now.
My track is slightly left (30 miles) of the 5:00 TPC official track.
Residents west of Biloxi to near the mouth of the Mississippi and east of Ft. Walton Beach, FL to near Cape San Blas, FL should closely monitor future updates in the event there is an unexpected Adjustment need to the forecast. Locations west of the mouth of the Mississippi and east of Cape San Blas are "all clear" for landfall.
To repeat…my forecast is for landfall between Biloxi, MS and Ft. Walton Beach FL.
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 (150 miles+) and he will affect a large area with strong Tropical Storm Force winds.
Impacts: Expect a storm surge of 12-15' near and to the right of where the center crosses the coast. This will swamp some of the barrier islands along with battering waves. There will also be significant water rises a good distance east of where the center crosses…along with very rough surf, swells and beach erosion. Intense hurricane force winds 115 mph + will affect an area near and to the right of where the center comes in….assuming a 125 mph hurricane at landfall…gusts could approach 140 mph near the core of the hurricane..along the barrier islands.
Rainfall of 6-12", with some locally higher amounts will affect a large area producing flooding.
Once onshore, Ivan will move SLOWLY North or NNE inland over Alabama….high winds will extend well inland and tree/powerline damage will be very extensive well up into Alabama.
Since Ivan will move only slowly, rainfall amounts inland through Alabama into eastern KY, TN and the western Carolinas could exceed 15"…this will be a big problem over the western parts of the Carolinas that just received 12"+ rains from Frances….flooding there could be extreme.
That's about it for now….If you live in my outlined swath please get preparations well underway tomorrow.
Next update…..3:00 tomorrow 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.