Just how strong was Alicia? What you are doing is betting that Rita won't do anywhere near as much damage as Katrina did 60 miles inland in Mississippi. Even if all you suffer is power outages, don't count on getting power back soon, because the utility workers will be spread out over ten's of thousands of square miles and some of the utility crews that could usually be counted on to pour in to help you will be spread out as far east as Mobile.
I hope I am wrong particularly because my cousin is a Houston cop and lives in NW Houston. Be sure and email me to tell me I am.
Minimal Cat 3.
Alicia was a Cat3 with a deadpan hit to the West beach of Galveston. If your son is in NW Houston, he should be fine.