Ida to Flood Gulf Coast -- Hurricane Season's Last Hit?

Willie Drye
National Geographic News
November 9, 2009
A weakening tropical storm Ida will bring minor flooding and power outages along the U.S. Gulf Coast (see map) when it comes ashore late tonight or early Tuesday, forecasters say.

Ida, which formed in the Caribbean Sea on November 4 as a tropical depression, quickly strengthened into a tropical storm, thanks to warmer waters and a lack of upper-level winds known as wind shear.

Hurricanes draw their power from the combination of warm ocean water and little wind shear.

Ida was briefly a Category 2 hurricane—with peak winds around 100 miles (161 kilometers) an hour on Sunday—as it passed through the Yucatán Channel from the Caribbean into the Gulf of Mexico.

But cooler waters and increased wind shear quickly reduced the storm's power.

"It's starting to fall apart," said Rusty Pfost, meteorologist in charge of the National Weather Service office in Miami.

(Related: "Jet Stream Shifts May Spur More Powerful Hurricanes.")

Rare Latecomer to Hurricane Season

Jeff Masters, meteorological director for the Web site Weather Underground, said Ida was the first November hurricane in the Gulf since Hurricane Kate in 1985.

That hurricane killed five people when it struck the Florida Panhandle on November 21, 1985, with peak winds of about 105 miles (169 kilometers) an hour.

Ida's peak winds are expected to be around 50 miles (80.5 kilometers) an hour at landfall, which are expected to cause a storm surge of up to 5 feet (1.5 meters) along the coast from the Louisiana-Mississippi border to the western Florida Panhandle. (Watch a storm surge video.)

Ida is the ninth tropical storm of 2009, but Masters doesn't think others are likely to form before the season ends on November 30.

"I think we're all done with hurricane season," he said.

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