Tropical Depression Nine has formed in the Atlantic and forecasters believe it could intensify into the season's first hurricane before arriving at the Gulf Coast. The National Hurricane Center says the system could escalate fast in the Gulf. AccuWeather and The Weather Channel are also watching Tropical Storm Isaias, which is developing on a similar path toward the coast.

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