Tropical Storm Nate

increases speed, and should reach the Gulf coast Sunday as a Category 1 hurricane.

A hurricane warning was issued for metropolitan New Orleans and Lake Pontchartrain as Tropical Storm Nate gained strength Friday, according to the National Hurricane Center.

With maximum sustained winds of 70 mph, Nate is moving north-northwest at 22 mph and was about 100 miles west-northwest of the westernmost tip of Cuba, and 500 miles south-southeast of the mouth of the Mississippi River, according to the hurricane center’s 11 p.m. update.

The storm is not expected to impact Central Florida.

Storm surge and tropical-storm warnings are in effect east of the Alabama and Florida border.

Nate is expected to continue picking up speed and was forecast to move into the southern Gulf of Mexico on Friday night, according to the advisory. It should approach the Gulf Coast tonight. Nate is expected to become a hurricane by the time it enters the northern Gulf and make landfall early Sunday near New Orleans, the hurricane center said.

A Category 1 hurricane packs winds between 74 mph and 95 mph, according to the Saffir-Simpson scale.

Gov. Rick Scott on Thursday declared a state of emergency in 29 counties in northern Florida.

Louisiana officials declared a state of emergency and ordered people to evacuate coastal areas and barrier islands. Evacuations began at some offshore oil platforms in the Gulf.

Nate drenched Central America with rain and has been blamed for at least 22 deaths. In Nicaragua, Nate’s arrival followed two weeks of near-constant rain that had left the ground saturated and rivers swollen. Authorities placed the whole country on alert.

Nicaragua’s vice president and spokeswoman, Rosario Murillo, said that at least 15 people had died in that country because of the storm.

Costa Rica’s Judicial Investigation Organism blamed seven deaths in that country on the storm and said 15 people were missing. Flooding drove 5,000 residents into emergency shelters.