A severe weather outbreak could hit the Plains beginning Sunday, with tornadoes, large hail and damaging winds all in play, and the threat may start building before that. Storms are possible from west Texas to Wisconsin overnight, with the best chance of severe thunderstorms through early Saturday in Iowa.
The setup becomes more focused Saturday afternoon and evening, when scattered supercell thunderstorms may fire in the Central Plains near a frontal boundary, a dryline and an area of low pressure. Those storms could organize into clusters overnight in Nebraska, Iowa and South Dakota, where damaging winds would be the main concern. Des Moines, Lincoln, Omaha and Sioux Falls are among the cities in the threat Saturday and Saturday night, and a couple of tornadoes are also possible overnight, especially in Iowa.
The threat matters now because it is not a one-night event. It may unfold in multiple rounds, first in the morning in the upper Midwest, then again in the afternoon and night in the Plains to upper Midwest. The most widespread danger appears to be in the area shaded in dark orange and red on the severe weather outlook, where an outbreak of thunderstorms with tornadoes, hail and damaging winds could develop. May is also the month with the most tornadoes in the U.S. on average, which makes this stretch of weather especially active for the calendar.
NOAA's Storm Prediction Center has already mentioned the potential for both strong tornadoes and a squall line of severe thunderstorms with damaging winds by Sunday evening in the Central Plains and upper Midwest. By Monday, the risk may broaden the most, possibly stretching from Texas to Michigan. The area most likely for severe weather Monday includes Des Moines, Kansas City, Madison, Omaha and Wichita, with tornadoes, damaging winds, hail and flooding rain all possible. By Monday evening, the agency has mentioned a risk for strong to intense tornadoes in parts of the Central Plains.
Tuesday could bring another round ahead of the frontal system, with severe thunderstorms possible from parts of the Southern Plains to the mid-Mississippi and Ohio Valleys, possibly into the Great Lakes. Wednesday and Thursday could add yet another chapter, with scattered severe storms possible again in parts of the South and possibly extending into parts of the East. For Omaha and other cities in the corridor, the question is not whether storms will form, but how many rounds of severe weather arrive before the pattern finally shifts.
