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Tornado Information and UpdateJune 6, 2012

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In the United States , the months in which tornadoes are most likely correspond to the times of year with increased solar heating and strong frontal systems.

Most of the early spring tornadoes in the U.S. tend to occur in the Southeast and South Central regions.

Gulf States, such as Mississippi and Louisiana are the frequent recipients of tornadoes from February to April.

Late spring tornadoes generally spread a bit farther north, often into Kansas, Nebraska and the Tennessee Valley region.

Tornado Information

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By mid-summer, most of Tornado Alley is active and tornadoes may occur throughout the United States.

Late summer tends to bring some of the stronger tornadoes into the upper Midwest and Ohio valleys, and the pattern shifts back southward into the late autumn.

The fewest tornadoes are documented during the winter months. Although rare, deadly winter outbreaks do occur.

Tornado Information

This really is a picture—the white streaks that you see are hail

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Tornado Alley (No formal Boundaries)

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The Enhanced Fujita Scale

EF-1 Wind: 86-110 MPH

Moderate damage. Roofs severely stripped; mobile homes overturned or badly damaged; loss of exterior doors; windows and other glass broken

EF-2 Wind: 111-135 MPH

Considerable damage. Roofs torn off well-constructed houses; foundations of frame homes shifted; mobile homes completely destroyed; large trees snapped or uprooted; light-object missiles generated; cars lifted off ground

EF-3 Wind: 136-165 MPH

Severe damage. Entire stories of well-constructed houses destroyed; severe damage to large buildings such (shopping malls); trains overturned heavy cars lifted off the ground and thrown; structures with weak foundations blown away some distance.

EF-4 Wind: 166-200 MPH

Devastating damage. Whole frame houses Well-constructed houses and whole frame houses completely leveled; cars thrown and small missiles generated

EF-5 Wind: > 200 MPH

Incredible damage. Strong frame houses leveled off foundations and swept away; automobile-sized missiles fly through the air in excess of 100 m (109 yd); high-rise buildings have significant structural deformation; incredible phenomena will occur

Tornadoes by State

Annual Tornado Fatalities by State

Tornadoes by Month

Tornadoes: Time of Occurrence