San Antonio - I find I-10 through SA to be an easy drive as long as I miss rush hour. Alternatives such at TX-46 from Boerne through New Braunfels to Sequin adds at least an hour normal driving in my experience with at least 10, maybe 15, stops at red lights. However, that route is preferable to rush hour in San Antonio. Some use Loop-1640 across the north part of San Antonio, and down to I-10.
I-10 Exit 540 in Boerne -> thru San Antonio -> I-10 Exit 610 at Sequin is 70 miles
I-10 Exit 540 in Boerne -> L-1640 -> I-10 Exit 610 at Sequin is 65 miles
I-10 Exit 540 in Boerne -> TX-46 thru New Braunfels -> I-10 Exit 610 at Sequin is 59 miles
Houston - same basic thing - straight thru is pretty easy as long as you avoid rush hour. Taking Beltway 8 (Toll on some parts) or I-610 around downtown doesn't really avoid any traffic. You really can't miss Houston without north at least as far as Conroe. Have to get off I-10 near Columbus and go north to near Navasota over to Conroe to Cleveland to Beaumont.
Weather - Tornados are not really a concern that far south. It takes the stronger weather changes north about Waco, Dallas and such to build the really strong tornado lines.
However they are a possibility anywhere any time of year. Have a system to check the forecast each day, and the flexibility to sit for a day or three if weather is bad.
Make sure you know which counties you are in/ passing through and listen to weather radio for watches and warnings. Remember a Watch means conditions are possible for severe weather to form, and a Warning is that severe weather is in the area.
More likely will be thunderstorms, winds off the Gulf of Mexico and heavy rain.
Today we are sitting in Livingston Texas, about an hour north of Houston, with heavy rain. So heavy that we are not going to head toward Texarkana until Sunday. Had planned to go today - but too much rain, too much flooding - and I really hate driving/ towing in rains so heavy it is hard to see 100 feet in front of my rig while driving.
