Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Sun May 03 2026 Valid 031300Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTHERN/CENTRAL MISSOURI AND CENTRAL ILLINOIS ON SUNDAY.... ...SUMMARY... A few strong thunderstorms are possible across parts of northern/central Missouri and central Illinois today. ...Synopsis... Early-morning satellite imagery shows broadly cyclonic flow across much of the CONUS. The only exceptions are along the West Coast, which is being influenced by an upper low just off the CA coast, and the Southwest States, where minor shortwave ridging exists. A low-amplitude shortwave trough is currently moving southward/southeastward within this broadly cyclonic flow through the Upper Midwest and northern Plains, with continued southeastward progression expected throughout the period. Recent surface analysis reveals a low over east-central MN, with a cold front extending southwestward into south-central NE before arcing back westward into far northeast CO and northwestward into central WY. This surface low, which is associated with the Upper Midwest shortwave trough, is forecast to progress eastward throughout the day, while gradually weakening. As it does, the cold front is expected to progress southeastward/southward, although the western portion of the front will gradually slow and eventually become stationary from southwest KS into northern MO this evening. Ascent along and atop this frontal zone will be the focus for potential isolated severe thunderstorm development this evening. ...Northern/central Missouri into central Illinois... Some modest low-level moisture advection is anticipated across the southern and central Plains today ahead of the southward progressing cold front. However, any notable low-level moisture (i.e. 60+ deg F dewpoints) will remain well south over south TX. This limited low-level moisture coupled with strong heating and mixing, should keep the airmass across the region capped through the afternoon and into the early evening. Thereafter, strengthening warm-air advection across the stalled front will combine with steep mid-level lapse rates to support moderate buoyancy and limited convective inhibition for parcels rooted around 700 to 800 mb. Cloud-bearing layer shear is sufficient for organization of any deeper, more sustained updrafts, and a few storms capable of isolated hail and/or damaging gusts are possible. ...Northern California/southwest Oregon... Thunderstorms are expected along the northern periphery of the upper low off the central CA coast. Increasing mid-level moisture and cold mid-level temperatures will support modest buoyancy amid moderate easterly flow aloft, supporting the potential for small hail and gusty winds with these westward progressing storms during the late afternoon/early evening. Even so, overall severe coverage is still expected to be less than 5%. ..Mosier/Dean.. 05/03/2026Read more