Some of the blog posts, emails, and phone calls we received during Tuesday's severe weather episode surprised me, because it is clear that a significant number of Central Texans still aren't clear on what they should do if a tornado (or very strong straight-line wind) threatens their location. I'm going to step through some basic safety rules, and I'll be glad to try to answer any questions you may have about protecting yourself and your family when severe weather approaches. Remember that weak tornadoes (the most common kind) have winds of 65 to 85 mph. Non-tornadic, straight-line winds of 65 to 85 mph can be just as dangerous as a weak tornado!

Go to the basement, if thewre is one.

Almost all serious injuries and deaths caused by tornadoes are the result of blunt force trauma, i.e. impact injuries caused by objects moving at very high speed (due to the wind speeds associated with tornadoes) striking the individual. Tornadoes (and sometimes, very strong straight-line winds) contain a debris field (composed of wood, metal, plastic, etc.) generated by what the tornado or wind encountered before getting to the victim. The very bext way to avoid being struck by this debris field is to be below ground! That's why the number one tornado safety rule is to take shelter in a basement of your home or whatever building you are in, if a tornado approaches. If you are fortunate enough to have access to a basement, there's another safety rule: take shelter in the basement by getting under a sturdy bench or table, if there is one. The idea is to protect yourself from falling debris, should a portion of the house or building collapse into the basement.

If no basement, go to an interior room on the lowest floor.

Alas, the vast majority of homes and apartments in Central Texas do NOT have basements. Most of our residential construction, and a significant portion of commercial construction, utilizes a solid concrete slab to support the building. (A few residences and commercial buildings have "safe rooms" that are concrete and steel reinforced that offer protection for occupants during a tornado.) So, let's step through the safety rules for homes and buildings that don't have a basement or a "safe room". If in a multi-story building, go to the lowest floor. Take shelter in a small central room (like a bathroom or closet) that has no windows or doors opening to directly to the outdoors. (The idea here is to put as many walls as possible between you and outdoors, so that the debris carried by the tornado is less likely to get to you.) After you are in the bathroom or closet, crouch down or lie flat on the floor, and cover your head and upper torso with padding, such as a mattress or sleeping bag. Remain in shelter until you are sure the danger has passed. In an office building, hospital, or skyscraper-like building, go to an enclosed, windowless area in the center of the building. Interior stairwells are usually good places to take shelter.

Abandon mobile homes for sturdier structures.

Another alas! Many Central Texans live in mobile or modular homes. The National Weather Service recommends that residents abandon mobile homes and seek shelter in sturdier buildings. Even mobile homes that are tied and anchored will disintegrate in a tornado. You are probably safer outside, taking shelter in a ditch or depression, than remaining in the mobile home. Get as far away from the mobile home as possible, and lie flat on the ground. Try to protect your head with your hands.

In a school.

At school, follow the tornado drill instructions. Take shelter in an interior room or hallway, crouch low, and protect your head with your hands. Stay away from windows and doors, and avoid large open areas like gymnasiums and auditoriums. Areas with large-span roofs present a very real threat of roof collapse in a tornado.

In a vehicle.

In a car or truck, if time and traffic conditions permit, drive AWAY from the tornado path at right angles. If time or traffic does not permit driving away, abandon the vehicle and get away from it so that it doesn't roll over on you. Lie flat on the ground, or in a ditch or depression. AVOID taking shelter under BRIDGES and OVERPASSES. The wind speed in a tornado is actually amplified (increased) by such structures. Don't be fooled by an old video that shows a TV news crew taking shelter under an interstate overpass ... that tornado did not strike the overpass directly. In the Oklahoma City tornado of 1999, people died taking shelter under overpasses.

In shopping malls or "box" stores:

In a shopping mall or large store, follow the instructions of security personnel. Move quickly to an interior room that has no windows or doors opening to the outdoors.

Remain calm!

In all cases, remain calm ... don't panic!