A flash flood warning is in effect for Travis County and to the south in Hays and parts of Caldwell, Comal and Guadalupe counties.
The National Weather Service says thunderstorms over those same areas are likely to produce flash flooding across the warning area.
Rains of one to two inches have already fallen over parts of the Austin metro area and south along the I-35 corridor.
Another one to three inches of rain is possible before it begins to decrease by around 5:30 this afternoon.
Authorities advise Austinites not to drive where water covers the road. Even SUVs and pickups can be swept away by as little as two feet of rushing water.
The flash flood warning is in effect until 6:30 p.m.
