SAVANNAH, GA (WTOC) - High pressure will build in today and continue into the weekend. Today will be mostly sunny and hot with a 20% chance for a shower or storm, highs 90-96 with a heat index up to 102. Mostly clear and quiet tonight with lows 68-78. Mostly sunny Thursday with a 20% chance for an afternoon shower or storm, highs 88-92. Mostly sunny Friday with a 20% chance for an afternoon shower or storm, highs 87-91. Fall officially begins Saturday at 9:54pm! Rain chances increase a bit Monday and Tuesday. Tropics are quiet for now with no active storms.