SAVANNAH, Ga. (WTOC) - Non-supercell tornadoes are circulations that do not form from organized storm-scale rotation. These tornadoes form from a vertically spinning parcel of air already occurring near the ground caused by wind shear from a warm, cold, or sea breeze front, or a dryline.
When an updraft moves over the spinning, and stretches it, a tornado can form. Eastern Colorado experiences non-supercell tornadoes when cool air rushes down off the Rocky Mountains and collides with the hot dry air of the plains.
Since these types of tornadoes happen mostly over scarcely populated land, scientists are not sure how strong they are, but they tend to be small.
One non-supercell tornado is a landspout. A landspout is a tornado with a narrow, rope-like condensation funnel that forms while the thunderstorm cloud is still growing and there is no rotating updraft - the spinning motion originates near the ground.
Waterspouts are similar to landspouts, except they occur over water. Damage from these types of tornadoes tends to be EF2 or less.
Tornadoes that come from a supercell thunderstorm are the most common, and often the most dangerous. A rotating updraft is a key to the development of a supercell, and eventually a tornado. There are many ideas about how this rotation begins. One way a column of air can begin to rotate is from wind shear – when winds at two different levels above the ground blow at different speeds or in different directions.
Vehicles are extremely risky in a tornado. There is no safe option when caught in a tornado in a car, just slightly less-dangerous ones. If the tornado is visible, far away, seek shelter in a sturdy building, or underground if possible.
If you can safely get noticeably lower than the level of the roadway, leave your car and lie in that area, covering your head with your hands. Avoid seeking shelter under bridges, which can create deadly traffic hazards while offering little protection against flying debris.
If you are caught by extreme winds or flying debris, park the car as quickly and safely as possible - out of the traffic lanes. Stay in the car with the seat belt on. Put your head down below the windows; cover your head with your hands and a blanket, coat, or other cushion if possible.