- After a relative lull, severe weather will roar back in the Plains starting Friday.
- This severe threat will persist through the weekend.
- Another round of severe weather may then follow in the Plains next Monday and Tuesday.
- Tornadoes, large hail, damaging winds and flooding rain are all threats.
Severe thunderstorms with tornadoes, damaging winds, large hail and flooding rain will return to the Plains Friday, lasting into early next week bringing an end to a relative lull in severe weather.
The jet-stream pattern will essentially flip late this week, taking a much farther southward plunge over the Rockies, then punching its energy east into the Plains states this weekend.
When this happens, wind shear – the change in wind speed and/or direction with height – is much higher, and warm, humid air streams into the Plains from the Gulf of Mexico.
This combination is expected to support severe thunderstorms as soon as Friday evening in the Plains, continuing into this weekend. A second jet-stream plunge is then expected to swing into the Plains early next week, triggering another round of severe weather.
Given May’s reputation as the peak month for tornadoes in the U.S. and saturated soil from recent heavy rain in the Plains, this active pattern has our attention.
(MORE: It’s Been Almost 6 Years Since the Last EF5 Tornado)
Severe Weather Outlook
Typical for severe weather outlooks several days away, some uncertainty remains in this forecast, but the generalities of some of the days ahead are becoming clearer.
Supercells and long lines of severe thunderstorms known as squall lines are both possible, at times, with tornadoes, damaging winds, large hail and heavy rain.
It’s too soon to determine details such as the magnitude and location of the tornado threat each day.
Here is our current forecast, for now. Check back with us at weather.com for important forecast changes in the days ahead as the details become clearer.
(MAPS: 7-Day U.S. National Forecast)
Scattered supercell thunderstorms are possible by afternoon or early evening in the High Plains from Nebraska to western Oklahoma and the rolling plains of West Texas.
This activity may evolve into one or more overnight thunderstorm clusters from west-central Texas to Nebraska, South Dakota, southwest Minnesota and Iowa.
Numerous severe thunderstorms are expected from parts of Nebraska and Iowa to central Texas, continuing into the night.
This is a more uncertain forecast, but at least some severe thunderstorms are possible from parts of the Mississippi Valley to east Texas and Louisiana.
Scattered severe storms are possible Monday afternoon in the Plains from Kansas, perhaps southern Nebraska, to western Oklahoma and the Texas Panhandle.
Next Tuesday, that severe threat may become more expansive in the Plains, somewhat analogous to Saturday, from the Corn Belt of Nebraska and Iowa to north Texas.
Flash Flood Threat
Repeated rounds of heavy rain over the past week or so triggered significant flooding in parts of Kansas, Oklahoma, Texas, Louisiana and Mississippi, including cities such as Houston; Baton Rouge, Louisiana; and Jackson, Mississippi, among others.
It was the wettest first 12 days of May on record in Dodge City, Kansas, the wettest such period since 1904 in Austin (Camp Mabry), Texas, and since 1978 in both Jackson, Mississippi, and New Orleans, according to the Southeast Regional Climate Center.
Soil moisture remains in the 99th percentile over a vast swath of the nation’s mid-section, and some rivers are still above flood stage from the northern Plains to the Gulf Coast.
These upcoming rounds of severe storms may produce at least locally heavy rain, at times, over parts of the saturated Plains or Mississippi Valley, potentially triggering flash flooding in at least some spots.
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It’s not yet clear whether next week’s thunderstorms will progress east in similar fashion to this weekend’s storms, or if the frontal boundary will stall in the Plains.
If the front stalls, this could lead to additional rounds of soaking thunderstorms which could raise the flood threat.
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