Williamson County is one of several in the Central Texas area subject to a National Weather Service severe thunderstorm warning issued just after 4 p.m.

What they're saying: Severe thunderstorms were located along a line in northern Williamson County moving southeast at 30 mph.

The NWS warning predicts 60 mph winds and quarter-sized hail. Hail damage to vehicles is expected, the NWS warning states, along with wind damage to roofs, siding and trees. Residents of both Travis and Williamson counties are advised to move indoors to an interior room on the lowest floor of a building immediately. Large hail, damaging winds and continuous cloud-to-ground lightning are already being observed.

The warning is set to expire at 5:15 p.m., giving way to a severe storm watch issued earlier in the day that expires at 9 p.m.