In the West, much cooler air is overspreading the Pacific Northwest, accompanied by widespread showers. In contrast, a ribbon of warm, dry weather stretches from central and southern California to the northern Intermountain West.

On the Plains, recovery efforts continue in the wake of the tragic tornado in Moore, Oklahoma. Thunderstorms have re-developed across portions of the southern Plains, including tornado-ravaged areas south of Oklahoma City. Meanwhile, very cool weather prevails across the northern and central Plains. Fieldwork remains at a standstill in the Dakotas, where rain showers persist.

In the Corn Belt, showery weather is halting most fieldwork, following last week’s phenomenal corn planting pace. Nearly half (43%) of the U.S. corn was planted during the week ending May 19, led by Illinois (57%), Iowa (56%), and Minnesota (52%). Similarly, 18% of the U.S. soybeans were planted during the 7 days ending May 19, paced by Michigan (36%), Ohio (29%), and Nebraska (26%).

In the South, locally severe thunderstorms are racing across several areas, including parts of Arkansas and western portions of Kentucky and Tennessee. A few heavy showers are also occurring along the southern Atlantic Coast. Across the remainder of the region, planting activities continue.

Outlook: A slow-moving storm centered over the upper Midwest will drift eastward, reaching the northern Atlantic States by Thursday. Another widespread outbreak of severe thunderstorms can be expected later today, especially from Michigan to eastern Texas. On Wednesday, lingering strong thunderstorms may spread as far east as the upper Ohio Valley and the lower Great Lakes region. Additional rainfall associated with the storm could reach 1 to 3 inches, especially in the Mid-South, Northeast, and along the southern Atlantic Coast. Elsewhere, much cooler air will arrive in the Far West, but heat will build by week’s end on the High Plains. The NWS 6- to 10-day outlook for May 26-30 calls for near- to above-normal temperatures nationwide, except for cooler-than-normal conditions in the Far West. Meanwhile, near- to below-normal precipitation across the majority of the U.S. will contrast with wetter-than-normal weather across the nation’s northern tier from the Pacific Northwest to the Great Lakes region.