The three groups of people most at risk during a tornado are those who are outdoors, those in mobile/manufactured homes, or those on the road in vehicles. The first two locations are detailed in other sections of this safety guide. How to handle severe weather situations on the road is detailed below.
In A Vehicle
Vehicles - cars, trucks, sport utility vehicles, RVs, 18-wheelers, boats, trains, planes, etc. - are terrible places to be when a severe thunderstorm threatens. Fortunately, these situations can be avoided most of the time by being ALERT to the possibility of severe storms and tornadoes.
All types of vehicles can be blown over, rolled, crushed, lifted or otherwise destroyed by even a weak tornado. People have been hurt or killed when large trees crushed their cars. Below are some safety tips.
Consider delaying your trip if severe thunderstorms are in the area or along your path of travel.
Monitor television, radio, NOAA weather radio, and the internet for storm location information.
Be familiar with the area where you're traveling. Keep a highway map handy, one that includes the county names and boundaries. NWS severe weather warnings are issued based on counties. If you do not know what county you're in you could miss life-saving information
If you're in your car, find a station broadcasting weather information. Some radio stations will interrupt programming to broadcast warnings and other information. Others are automated stations and may not. Search for a station with local weather information and listen for details. A battery operated weather radio is essential for travelers. Remember you will not get any warnings if you are listening to CD's or satellite radio in your vehicle.
The chances of being hit directly by a tornado in your car are very small. However, severe thunderstorms contain other deadly and destructive elements that can threaten your life in your car:
Severe thunderstorms can produce hail as big as baseballs or softballs. These chunks of ice, falling at over 100 mph from a severe thunderstorm, will break car windshields and dent vehicles bodies. Get off the roadway if possible and find shelter underneath an awning, a carwash or other structure. Abandon your vehicle if possible and get into a sturdy structure. Do not park underneath highway overpasses or bridges. You could cause a deadly traffic jam, preventing others from reaching safe shelter and blocking emergency vehicles.
Severe thunderstorms can produce devastating straight line winds, as strong, or even stronger than most tornadoes. Any vehicle may be overturned by severe thunderstorm winds. Get off the road, if possible, and find a sturdy building to take shelter in.
Heavy Rain & Flooding:
Even non-severe thunderstorms can produce excessive rainfall in a very short period of time that can flood roadways and low water crossings. Avoid areas where water is covering the roads - even familiar ones.
Every situation is different, and if faced with a tornado threat while on the road, your best course of action will depend on your exact location, the tornado's location, speed, and direction of movement, road options available to you, nearby structures, time of day, traffic, weather conditions you're experiencing.
If the tornado is far enough away and road options and traffic allow, you should try to find a substantial building for shelter. Follow the basic tornado safety guidelines (get in - get down - cover up). Motorists have found truck stops, convenience stores, restaurants and other businesses to be adequate shelters in a tornado situation. Walk-in coolers can sometimes make a good shelter.
While you should never try to outrun a tornado in your vehicle, you may, in some situations, be able to get out of the tornado's way by driving out of its path, or simply stopping and allowing the tornado to pass. Again, this can be extremely dangerous unless traffic, time of day and road options allow you to see the tornado, determine which way it's moving (and how fast), find a road option that will take you out of its path (while avoiding other storms) and to safe shelter.
The worst-case scenario for motorists would be to be trapped in your vehicle on the road with no escape possible. This scenario could occur in more densely populated areas, in metropolitan areas at rush-hour or in high traffic situations, or on limited access roadways, such as interstates or turnpikes, where it might not be possible to quickly exit and find safe shelter. It is in these situations when it may become necessary to leave your vehicle and seek shelter in a ditch, culvert or low spot.
Highway overpasses are NOT tornado shelters, and these should be avoided. The reasons, which are numerous,
Taking Shelter Outdoors:
Ditches, culverts, and ravines should be used only as an absolute last resort. You will be exposed to flying debris, rain and hail, lightning and extreme wind. People have survived by seeking shelter in ditches, but people have also died. If you must leave your vehicle to seek shelter in a ditch, you should try to get as far away from the vehicle, as well as any other potential "missiles" as possible.
Content Courtesy of National Weather Service Weather Forecast Office