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.
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.
Saturday's Thunderstorm Outlook
- Threat area: Severe thunderstorms are expected to develop along the dryline (a kind of front that differentiates between moist air to the east and dry air to the west) from northern Texas northward into Oklahoma and Kansas. Regions illustrated in red within the inset map (right) should prepare for damaging winds, hail and possible tornadoes. Some tornadoes could be strong (EF2 or higher rating).
- Cities: Abilene, Texas | Oklahoma City | Wichita, Kan.
Sunday's Thunderstorm Outlook
Sunday's Thunderstorm Outlook
- Threat area: As the surface low pressure system pushes east, more severe thunderstorms will spark up Sunday from central Texas northward into parts of Oklahoma, Kansas, Nebraska, Arkansas and Missouri. Regions illustrated in red within the inset map (right) should prepare for damaging winds, hail and possible tornadoes.
- Cities: San Antonio, Texas | Dallas-Fort Worth | Oklahoma City, Okla. | Tulsa, Okla. | Kansas City, Mo. | Fort Smith, Ark.
Monday's Thunderstorm Outlook
- Threat area: The storm system will continue to shift slowly east, pushing the severe threat into areas either side of the middle and lower Mississippi Valleys. Regions illustrated in red within the inset map (right) have the greatest chance of seeing severe storms.
- Cities: Jackson, Miss. | Little Rock, Ark. | St. Louis, Mo. | Memphis, Tenn.
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