Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather
By: Dr. Jeff Masters , 8:56 PM GMT on September 08, 2008
Cuba continues to take a pounding from Hurricane Ike, which smashed ashore in eastern Cuba last night as a Category 3 hurricane with 120 mph winds. Ike's winds have since weakened to borderline tropical storm/Category 1 strength, according to the latest data from the Hurricane Hunters. At 2 pm EDT, an Air Force Hurricane Hunter aircraft found top surface winds of 65-70 mph--just below hurricane force. At 2 pm CDT, Jucaro, Cuba on the south coast of the island reported sustained winds of 49 mph.
Figure 1. NASA MODIS satellite image of Hurricane Ike's eye at 1 pm EDT Sunday 9/7/08. Ike had just crossed Great Inagua Island (right) as a Category 4 hurricane with 135 mph winds. Damage was extreme on the island, as well as nearby Grand Turk Island, but no deaths or injuries were reported. Image credit: NASA Earth Observatory.
Track forecast for Ike
Ike's center moved out over the warm western Caribbean waters late this morning, and is now tracking west to west-northwest, closely hugging the south coast of Cuba. Ike is expected to track west-northwest on Tuesday into the Gulf of Mexico, passing near or over Havana, Cuba. The expected track could bring tropical storm force winds of 40-50 mph to Key West and the Lower Keys on Tuesday afternoon.
The latest 12Z (8 am EDT) computer models continue to show that Ike will track northwest into the central Gulf of Mexico on Tuesday and Wednesday. However, there has been a major shift in the model tracks for Thursday and Friday. All of the models are calling for a more westward motion, bringing Ike to a landfall in Texas sometime Friday afternoon through Saturday morning. The new set of model runs is portraying stronger high pressure over the central Gulf on Wednesday and Thursday will push Ike faster than expected to the west. The trough of low pressure expected to turn Ike to the north does not arrive until Friday night, after the storm has already made landfall in Texas. The timing and strength of this trough, plus the speed with which Ike moves across the Gulf this week are still uncertain. We cannot be confident yet of a Texas landfall until we see several model runs in row that lock in on this solution. All five major models--the GFS, UKMET, GFDL, HWRF, and ECMWF--foresee a landfall between Corpus Christi and Port Arthur. The GFDL model foresees landfall as a Category 2, and the HWRF as a Category 3. Landfall could be as early as Friday afternoon, or as late as Saturday morning.
Intensity forecast for Ike
Although Ike is currently over some very warm waters, the eye is very close to the coast. This proximity to land will inhibit intensification. Furthermore, the Hurricane Hunters reported at 2 pm EDT that Ike had concentric eyewalls--an inner eyewall of 17 miles in diameter, and an outer eyewall of 70 miles in diameter. Hurricanes in this configuration cannot intensify significantly until the inner eyewall collapses, and the outer eyewall takes over. This process typically takes a day, and Ike will be back over Cuba before this "Eyewall Replacement Cycle" (ERC) has had time to complete. I expect that Ike will intensify by at most 10 mph while it is over water south of Cuba. This is good news for Havana, which should only get a strong tropical storm or weak Category 1 hurricane on Tuesday morning.
Ike should emerge into the Gulf of Mexico Tuesday relatively intact. It will take the storm a day or two to reorganize once over the Gulf, where wind shear is expected to be light (<10 knots) and water temperatures will be warm, near 30°C. Ike should be able to intensify into a Category 3 or 4 hurricane by Thursday, as forecast by the GFDL and HWRF models. Once Ike approaches the coast on Friday, the total heat content of the ocean declines, and the shear is forecast to rise to a moderate 15-20 knots. The GFDL and HWRF models respond by weakening Ike to a Category 2 or 3 hurricane at landfall in Texas. This is a reasonable forecast, but our skill in forecasting intensity is low, and Ike could just as easily be a Category 1 or Category 4 hurricane at landfall.
Watching the remains of Josephine
The remains of Tropical Storm Josephine are near 19N, 46W, in the middle Atlantic Ocean, and have grown less organized today. The storm still has some spin, but it slowly losing it. A large area of dry Saharan air surrounds the system, and Josephine currently has no heavy thunderstorm activity. This will be my last mention of it, since it appears to be dissipating.
The tragedy in Haiti
The death toll in Haiti due to the onslaught of Hurricanes Gustav, Hanna, and Ike, plus Tropical Storm Fay, grew to at least 630 today, as more victims of Hurricane Hanna were identified. Rains from Hurricane Ike have killed at least 61 people, and the death toll is sure to rise higher as rescuers reach more remote flooded areas in coming days. Haiti needs all the help it can get, and I want to thank all of you who donated to the Lambi Fund of Haiti charity I recommended yesterday. I've heard from the administrators of the charity that several hundred of you have made on-line donations. Wow! Heartfelt thanks!
Figure 2. The flooded city of Gonaives after Hurricane Hanna, September 3, 2008. Image credit: Lambi Fund of Haiti.
I'll have an update Tuesday morning.
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