Your local officials will tell you. During a Hurricane Watch, listen to your radio or television constantly. Emergency officials can interrupt routine broadcasts to give special weather updates, warning messages, and evacuation information. Messages will also be disseminated through Social Media (Facebook, Twitter, Youtube and Instagram.)
National Weather Service
For 24-hour weather broadcasts from the National Weather Service, tune to NOAA Weather Radio on the high-band FM frequency 162.55 megahertz (MHz) that broadcasts from Galveston, 162.40 MHz that broadcasts from Houston, or 162.425 MHz that broadcasts from Bay City.