The United States experiences more than 1,000 tornadoes a year.
While most storms are weak and occur in sparsely populated areas, recent storms have inflicted heavy casualties in more populated regions of the country. Moore, OK, Tuscaloosa, AL, and Joplin, MO are the most recent communities to suffer.
Tornadoes form when large air masses of different temperatures collide; when cold, dry air runs into warm moist air, which rises, condenses into heavy rain, and then falls in powerful downdrafts. These conditions occur most often in the Great Plains, where the high altitude jet stream from the west converges with warm, moist air moving north from the Gulf of Mexico, and warm, dry air from the southwest.
One week after a devastating tornado hit the southern Plains of Oklahoma; a similar weather pattern is being repeated.
Earlier today the NWS Storm Prediction Center issued a moderate to severe threat warning for thunderstorms, tornadoes, large hail, and damaging winds, Wednesday afternoon and evening for parts of the central and southern Plains, including parts of Nebraska, Kansas, Oklahoma and Texas.
If you live in the areas of high risk, please be alert to changing weather conditions. Look for the following danger signs:
- Dark, often greenish sky
- Large hail
- A large, dark, low-lying cloud (particularly if rotating)
- Loud roar, similar to a freight train.
If you see approaching storms or any of the danger signs, be prepared to TAKE SHELTER IMMEDIATELY.