Nov. 8 (Bloomberg) -- Hurricane Ida strengthened after entering the Gulf of Mexico and headed toward the U.S. coast, where a hurricane warning is in effect from Mississippi to the Florida panhandle.

Ida’s maximum sustained winds increased to about 105 miles (169 kilometers) per hour, from 100 mph earlier today, the U.S. National Hurricane Center said in its latest advisory. Ida was 400 miles south-southeast of the mouth of the Mississippi at 9 p.m. New Orleans time, the center said.

The Category 2 storm was moving north-northwest at 14 mph and Ida’s eye is forecast to cross the U.S. Gulf Coast near Pensacola in the Florida panhandle at about 6 a.m. on Nov. 10, according to the NHC’s three-day forecast.

“Preparations to protect life and property should be rushed to completion,” the NHC said in its advisory.

The hurricane warning, meaning hurricane conditions are expected within 24 hours, is in effect from Pascagoula, Mississippi, to Indian Pass, Florida, the agency said.

A hurricane watch, meaning such conditions are possible within 36 hours, is in effect from Grande Isle to New Orleans, while a tropical storm warning was issued from Indian Pass to Aucilla River in Florida.

Louisiana Governor Bobby Jindal declared a state of emergency and the National Guard was put on high alert, the Associated Press reported. School classes were canceled for tomorrow and the next day in parts of the western Florida panhandle, AP said.

Oil Rises

Crude oil rose from a one-week low after Ida entered the Gulf, which accounted for 28 percent of U.S. output in June, and other storms shut export terminals and production in Mexico. Chevron Corp. began evacuating some personnel to prepare for Ida. The storm hasn’t affected production.

Ida is a Category 2 storm, the second-weakest on the five- step Saffir-Simpson scale and assigned for tropical cyclones with winds of between 96 and 110 mph. Such storms are capable of causing “widespread damage,” according to the NHC.

The storm is forecast to gradually weaken tomorrow, the NHC said. It is expected to remain at hurricane strength until making landfall, the center said.

Ida, the ninth named storm of the 2009 Atlantic hurricane season, strengthened into a hurricane for the second time earlier today after weakening when it made landfall in Nicaragua and Honduras three days ago. The system formed in the southwestern Caribbean Sea on Nov. 4.

Flooding and mudslides from the storm killed at least 91 people in El Salvador, Jorge Melendez, the head of the country’s civil defense agency, said at a press conference in San Salvador today. The most affected areas are the coffee-growing regions in central El Salvador, officials said.

To contact the reporters on this story: Dan Hart in Washington at dahart@bloomberg.net; Aaron Sheldrick in Tokyo at asheldrick@bloomberg.net.

Last Updated: November 8, 2009 22:48 EST