Saturday, September 6, 2008

Hurricane Watch: "Ike's coming to the Gulf. Time to pay attention."

UPDATE: Sunday, 6:00 p.m. EDT.
From the Houston Chronicle's SciGuy:

If you live along the Gulf of Mexico, and you're wondering when to become concerned about Hurricane Ike, the time is now.

After encountering wind shear during the last 24 hours the storm's winds have fallen to 115 mph (UPDATE: 110 mph at 10 a.m.), but Ike is now moving away from the strongest shear and should slowly re-strengthen as it moves west-southwest toward Cuba or Florida. Interaction with either landmass would weaken Ike, but it's still probable a large hurricane will enter the Gulf of Mexico early next week.

And such a storm, like Gustav, would pose a grave threat to the U.S. Gulf Coast.

THE TURN

imageUFQwesterlies.jpg

Tropical systems move vast amounts of heat from the tropics toward the poles. As such, most storms form in the eastern regions of the Atlantic tropics, and move west due to the easterly trade winds.

While doing so the storms gain latitude and gradually encounter the westerlies between 30 to 60 degrees that predominantly affect U.S. weather. Once subject to these westerlies, a tropical storm turns northward and typically begins moving toward the northeast, taking its heat poleward....MORE




From the South Florida Sun-Sentinel:
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From Jeff Masters' Wunderblog:
...Track forecast for Ike
The latest 06Z (2 am EDT) computer models foresee a probable direct hit by Ike on Grand Inagua Island in the Southeast Bahamas, with the Turks and Caicos Islands also getting hit hard. The eye is about 27 miles in diameter, so a region about 50 miles wide will feel Category 3 hurricane winds in the Southeast Bahamas. These islands can expect a storm surge of 6-12 feet, and extreme damaging winds. Ike will pass 40-80 miles north of northwestern Haiti, and will bring rains of 3-6" to the Dominican Republic, and 4-8" to northern Haiti. These rains will likely cause additional severe flooding in Haiti, where the death toll is nearing 200 in the aftermath of Hurricane Hanna.

All of the major models agree that Ike will hit eastern Cuba on Sunday night. After this point, the models diverge. A southern camp of models, the ECMWF and UKMET, take Ike across eastern Cuba and into the western Caribbean, then through the narrow Yucatan Channel between Cuba and Mexico's Yucatan Peninsula, eventually hitting Texas a week from now. This track would bring tropical storm conditions to the Cancun/Cozumel area beginning Tuesday afternoon or evening, with possible hurricane conditions by Wednesday morning.

The northern camp of models, including the GFS, NOGAPS, GFDL, and HWRF, turn Ike west-northwest over Cuba, forecasting that Ike will pop off the coast of Cuba near the Florida Keys on Tuesday, then swing north to threaten the west coast of Florida. The NOGAPS and GFDL both forecast that Ike will pass within 50 miles of Tampa on Thursday, while the GFS and HWRF put Ike several hundred miles off the west coast of Florida. I'm leaning towards this northern solution, since the GFDL model has been performing so well for both Ike and Gustav. The GFDL forecasts Category 3 strength winds will affect Key West and the Upper Keys, despite a track by Ike over Cuba....