FLORIDA, United States (AFP) — Tropical Storm Bertha spread across northwestern Florida Tuesday, where it was predicted to bring coastal flooding and heavy rainfall, the National Hurricane Center said.

The second named storm of the Atlantic season was about 90 miles (145 kilometres) southwest of Panama City, Florida, packing maximum sustained winds of 60 mph as it turned westward. Bertha was expected to begin weakening by Wednesday.

Tropical storm warnings — as well as lower-grade watches — were in effect in parts of Florida and Louisiana.

“Tropical storm conditions will continue spreading across portions of the warning area later today through Wednesday,” the NHC’s latest advisory said.

A combination of storm surge and tide will cause normally dry areas near the immediate coast to be flooded, the NHC said.

Bertha was expected to produce 2 to 4 inches of rainfall, with isolated totals around 6 inches, through Thursday, from western Florida into southern Louisiana, making flash flooding possible, especially in urban areas.

Officials have forecast a below-normal Atlantic hurricane season this year, which runs from June 1 to November 30, because of the return of El Niño conditions that suppress hurricane activity in the Atlantic basin.

An average season has 14 named storms and seven hurricanes, including three major hurricanes.