From the Spaceflight Meteorology Group:

A strong cold will pass through JSC between midnight and 1AM tonight. Winds will shift to the north and northwest and become breezy. Temperatures will begin to fall into the 40s by sunrise and continue to fall during the day Thursday. Freezing temperatures are possible from 2AM – 9AM Friday morning. Forecast low at JSC Friday morning is 31. Wind chill index will be in the 30s Thursday and 20s Friday morning. A few hours of near freezing or freezing temperatures are likely again on Saturday morning.

Rain chances and possibly a thunderstorm increase tonight with about 0.5 inch forecast overnight. A few periods of cold rain are likely Thursday before tapering off early Friday morning. There is a small window for some very light, very brief, very light freezing rain near JSC late Thursday night. Ground temperature should remain relatively warm so no significant ice accumulation is expected as of now at JSC, except perhaps on some signs, hand rails and elevated structures. A Winter Weather Advisory is out for areas in Harris county just W & NW of JSC from 2PM Thursday to 9AM Friday.