In the West, mild, dry weather is returning to the Pacific Northwest, but unusually cool conditions linger across the remainder of the region. The Northwestern warmth is promoting the development of winter wheat and spring-sown small grains.

On the Plains, locally severe thunderstorms persist this morning, especially from eastern Oklahoma into north-central Texas. Meanwhile on the central High Plains, a frost advisory is in effect early today across portions of eastern Colorado and northwestern Kansas, for low temperatures near 30 degrees F.

In the Corn Belt, locally heavy showers and thunderstorms stretch from Michigan to Missouri. Recent and ongoing Midwestern rainfall has slowed or halted planting activities and caused local flooding, but in general has benefited emerging corn and soybeans.

In the South, scattered showers are mostly confined to areas west of the Delta. As a result, pockets of dryness or drought continue to expand in the central Gulf Coast States and the southern Mid-Atlantic region. Warm, dry weather favors fieldwork throughout the Southeast.

Outlook: Typical spring weather will prevail for the next five days, with 1- to 4-inch rainfall totals and locally severe thunderstorms expected from the central and southern Plains into the lower Midwest and much of the East. Showers can also be expected in the Northwest, but mostly dry weather will prevail across the northern High Plains and the Southwest. Warmer air will expand across the West, reaching the northern Plains by early next week. The NWS 6- to 10-day outlook for May 18-22 calls for cooler-than-normal weather in New England and the Pacific Northwest, while near- to above-normal temperatures will prevail across the remainder of the U.S. Meanwhile, above-normal precipitation from the Pacific Northwest to the northern Plains and in much of the East will contrast with drier-than-normal conditions in the Mississippi Valley.