Tropical depression could form in Gulf Coast this week USA TODAYInvest 91L to become tropical storm or hurricane as millions along Gulf Coast prepare for potential impacts Fox Weather Texas activates emergency response resources as tropical wave brews in the Gulf KHOU.comSunday Tropics Update: Francine forming today or tomorrow KPRC Click2HoustonStorm tracker: NHC tracking 2 Atlantic tropical waves, one could bring rain to US USA TODAY