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Significant Severe Weather Threat, Including Tornadoes, This Weekend and Early Next Week

April 25, 2014

It's been a relatively quiet start to the severe weather season this year.

To date, not one tornado of EF3 intensity or stronger has been observed anywhere in the U.S. In addition, no tornado-related deaths have been recorded thus far in the U.S. in 2014 through April 24.

(MORE: 2014 Remains Fatality-Free for Tornadoes | Record-Long Wait for Year 's First EF3)

However, the weather pattern is now changing and it appears the threat of severe weather will ramp up through the next five days or so.

If you live from the Plains eastward into parts of the Mississippi Valley, Ohio Valley and South, take note: A potentially significant severe weather threat, including tornadoes, is forecast to develop this weekend and continue into early next week. 

Severe Weather Setup

Background

Disturbance Moves In

Disturbance Moves In

Disturbance Moves In

Disturbance Moves In
Background

Unstable Air Coupled with Wind Shear

Unstable Air Coupled with Wind Shear

Unstable Air Coupled with Wind Shear

Unstable Air Coupled with Wind Shear

Heading into the weekend, a strong, upper-level disturbance will travel east from the Rocky Mountains into the nation's midsection. As it does so, it will pull warm, moist air ahead of it into the central and southern Plains. Warm, moist air is buoyant, and it will easily rise, especially with a few hours of sunshine. This rising air is called atmospheric instability, and it will provide the "fuel" necessary to sustain severe thunderstorms.

By late Saturday and Sunday, a surface low will develop within the central Plains. Ahead of this low, moist air will continue to stream into the Great Plains from the south. At the same time, faster mid-level winds will blow into the Plains from the west, resulting in wind shear (a change in wind speed and direction with height). Wind shear allows thunderstorms to tilt as they build higher in the sky, and the result is long-lived, particularly strong thunderstorms called supercells.

With enough wind shear and instability, supercell thunderstorms can produce and sustain tornadoes in addition to large hail and damaging wind gusts.

This storm system will continue to progress slowly eastward into early next week with multiple rounds of severe storms likely.

For details on the severe threat areas each day, click here.

MORE: Where to NOT Take Shelter During a Tornado

 


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