ignificant Severe Weather Threat, Including Tornadoes, This Weekend and Early Next Week for Plains

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 22.
(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 or six days.
If you live in the central and southern Plains, take note: A potentially significant severe weather threat, including tornadoes, is forecast to develop this Saturday and continue into Sunday. By Monday, severe storms may push as far east as the Mississippi Valley.
This is in addition to the severe storms we are tracking with the current weather system Wednesday into Thursday.
Heading into Saturday, a strong, upper-level disturbance will travel east from the Pacific into the Rocky Mountains. 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 early 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.
(MORE: The Science Behind Supercell Thunderstorms)
As is typical several days in advance, there remains some uncertainty in the exact details. This includes the magnitude and location of the greatest tornado threat each day. We will provide more updates as we get closer to this potential outbreak so that you can be prepared. If you have outdoor plans this weekend, be sure to have a way to get the latest weather information and make yourself aware of the closest shelter to your location.

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