Tropical Storm Bertha strengthens off Florida panhandle

Tropical Storm Bertha strengthened in the Gulf of Mexico and was moving slowly toward the Florida Panhandle and Alabama, causing a tropical storm warning and storm surge watches.

The storm was about 110 miles south of Panama City, Florida, and 170 miles southeast of Mobile, Alabama, and moving northwest at 5 mph with maximum sustained winds of 50 mph, the National Hurricane Center said Tuesday morning.

The wind speed increased by 10 mph since Bertha formed on Monday night. 

A tropical storm warning, meaning the conditions are expected within the warning area within 36 hours, was in effect early Tuesday from the Florida and Alabama border to Louisiana.

A storm surge watch, indicating rising, possible life-threatening water moving inland from the coast within 48 hours, was issued from the Alabama and Florida border to the mouth of the Mississippi River.

The storm was expected to stay near or along the northern Gulf Coast this week, dropping heavy rain on coastal areas of Florida, Alabama, Mississippi and Louisiana while pushing west toward Texas.

Bertha is the second tropical storm of the Atlantic hurricane season after Tropical Storm Arthur brought heavy rainfall to the southeastern U.S. in June.