The above image was taken from the New Braunfels, TX radar about 7 minutes ago. You can see the center of Tropical Storm Hermine located just Southwest of George West, TX. Hermine is moving North/Northwest at 15 mph.
Heavier rainfall rates of up to 1 inch per hour are now spreading into the I-35 corridor region from San Antonio to Austin. The image below shows the 1-hour rainfall rate as estimated by the same radar:
I have zoomed in on the image so that you can see the greater Austin area. The darker green and yellow areas to the Southeast of Austin show areas of 0.75 to 1.5 inch rainfall rates per hour. These heavier rainfall rates will continue spreading Northwest into the Austin area over the next 2-3 hours. This will result in an increased urban and small stream flooding risk in the metropolitan area. This will primary affect areas from the Kyle/Buda area on North into Austin.
Another area of enchanced rainfall rates will move into the San Antonio area from the Southeast this morning, in association with the center of Hermine and an band of locally heavier rain surrounding that center.
If you live or have to travel through flood-proned areas along the I-35 corridor from San Antonio to Austin, use extreme caution.