Tropical Depression Nine has developed in the Atlantic and forecasters believe it could intensify into the season's first hurricane before making landfall on 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 moving along a comparable track toward the coast.

Separately, an AccuWeather heat advisory remains active for inland areas near San Francisco until 10 p.m. Thursday. Coastal areas are not included in the warning.