ACUS01 KWNS 040600

SWODY1

SPC AC 040558



Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

1258 AM CDT Mon May 04 2026



Valid 041200Z - 051200Z



...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS

OF THE MIDWEST INTO THE CENTRAL/SOUTHERN PLAINS...



...SUMMARY...

Strong to severe thunderstorms capable of large hail and damaging

wind are possible across portions of the Midwest late Monday

afternoon into Monday night. A conditional threat for severe storms

with large to very large hail extends into portions of the

central/southern Plains.



...Synopsis...

Strengthening mid-level flow will move out of Canada today,

deepening the Eastern US trough, with a surface low developing

across Ontario and a cold front shifting south across the northern

Plains into the central Plains and Midwest. Across the west, flow

will strengthen in within a cutoff low just off the shore of

California before overspreading portions of the Southwest into the

Southern Plains. A surface low is expected to develop across Kansas,

with a dryline extending south into Oklahoma/north Texas. Areas of

strong to severe storms will be possible from the Midwest into

portions of eastern Kansas and south into Oklahoma/northern Texas.



...Eastern Kansas into Mid-Mississippi Valley...

Thunderstorm development will likely be delayed until the late

afternoon/evening across eastern Kansas into Missouri owing to

strong MLCIN and generally weak forcing. Daytime heating and dew

points in the mid 50s to 60s should yield moderate MLCAPE across a

region from eastern Kansas northward into Missouri and western

Illinois. As the low-level jet increases into the evening with the

cold front shifting south, scattered thunderstorm development is

expected. Initially, strongly sheared profiles and steep lapse rates

will support supercells capable of large hail and damaging wind,

primarily across eastern Kansas. Through time as additional storms

develop and cluster along the front, the risk for damaging wind may

increase. A few CAM members suggest a few clusters/bowing segments

may move across northern Missouri and west-central Illinois, though

there is disagreement in location/timing. A corridor of higher wind

probabilities and upgrade to Slight may be warranted as details

become clearer.



...Lower Great Lakes Vicinity...

Scattered thunderstorm development will continue further north into

the Great Lakes region along the cold front. Moisture becomes more

limited with northern extent which may limit the severe threat.

However, strong flow aloft and steep lapse rates may still support

downward mixing and swaths of strong to severe wind.



...South-central Kansas into Oklahoma and northern Texas...

A more conditional threat for storms will exist along the dryline

across southern Kansas into central Oklahoma and northern Texas.

Strong daytime heating is expected across this region along and

behind the dryline. Forecast sounding comparison indicates the

dryline circulation will be strong and deep through the afternoon.

Mid-level capping will likely inhibit convection until stronger flow

aloft overspreads the region by the late afternoon/evening. The

low-level jet will also strengthen at this time, with MLCIN eroding.

It is possible that an isolated supercell or two could develop and

produce large to very large hail (some 2+ inches). The best signal

for this is near the Red River in southern Oklahoma/northern Texas.

However, a few members do have development further north across

northern Oklahoma and into southeastern Kansas.



..Thornton/Lyons.. 05/04/2026



$$