Original article from safetydailyadvisor.blr.com
By Chris Kilbourne
The first thing employees should know about tornadoes is the difference between a tornado watch and a tornado warning. Many people have these two mixed up.
- A tornado watch means tornadoes are likely to occur in the watch area. Be ready to act quickly and take shelter, and check supply kits. Monitor radio and television stations for more information.
- A tornado warning means an imminent threat—a tornado has been sighted in the area or has been indicated by radar and you must take shelter immediately.
Identifying Shelter Locations
An underground area, such as a basement or storm cellar, provides the best protection from a tornado. If an underground shelter is unavailable, OSHA advises people to consider the following:
- Seek a small interior room or hallway on the lowest floor possible. Rooms constructed with reinforced concrete, brick, or block with no windows, a heavy concrete floor, and a sturdy ceiling or roof system overhead make the best shelters.
- Stay away from doors, windows, and outside walls.
- Stay in the center of the room, and avoid corners because they attract debris.
- Avoid auditoriums, cafeterias and gymnasiums that have flat, wide-span roofs.
If caught outdoors when a tornado is threatening seek shelter in a basement or a sturdy building, if possible.
If in a vehicle, there are two options:
- If there is an area which is noticeably lower than the roadway, get out of your vehicle and go lie in that area with your head covered by your hands and forearms.
- If there is nowhere to shelter, stay in the vehicle with the seat belt on, keeping your head below the windows and covering your head with your hands or a blanket.
Although weather alerts on the Internet or TV are probably the best source of information about an impending tornado, OSHA reminds us that there is no substitute for staying alert to the sky.
Besides an obviously visible tornado, here are some things to look and listen for:
- Strong, persistent rotation in the cloud base
- Whirling dust or debris on the ground under a cloud base (some tornadoes don’t have a funnel)
- Hail or heavy rain followed by either dead calm or a fast, intense wind shift
- Loud, continuous roar or rumble, which doesn’t fade in a few seconds like thunder
- At night, small, bright, blue-green to white flashes at ground level near a thunderstorm (as opposed to silvery lightning up in the clouds), which mean power lines are being snapped by very strong wind, maybe a tornado.
- Also at night, persistent lowering from the cloud base, illuminated or silhouetted by lightning, especially if it is on the ground or there is a blue-green-white power flash underneath