Tropical Depression Nine has developed in the Atlantic and forecasters expect it to strengthen into the season's first hurricane before making landfall on the Gulf Coast. The National Hurricane Center says the system could strengthen rapidly in the Gulf. AccuWeather and The Weather Channel are also watching Tropical Storm Isaias, which is advancing on a like course toward the coast.

Separately, an AccuWeather heat advisory continues for inland areas near San Francisco until 10 p.m. Thursday. Coastal areas fall outside the warning.