From the Spaceflight Meteorology Group:

At 9:10 AM a line of thunderstorms located 12 miles northwest of JSC was moving east at around 30 mph. Gusty winds up to 40 mph will likely accompany the onset of the line in the vicinity as well as brief heavy rains. The leading edge of this squall line has prompted a few tornado warnings this morning generally on a track well north of JSC and NASA Ellington Field.  A Tornado Watch is in effect for JSC into this afternoon.  Rain should clear out between noon and 1 PM with rapid clearing and some breezy west winds.