In the West, warm, dry weather favors a rapid pace of fieldwork and crop development. Slightly cooler air is just starting to overspread the Pacific Northwest, accompanied by isolated showers.

On the Plains, much warmer weather accompanies scattered rain showers in the Dakotas. Elsewhere, very warm, dry weather prevails. High temperatures above 90°F will be common later today throughout the region, even as far north as the Dakotas.

In the Corn Belt, frost and freeze advisories were in effect early today from the Mississippi River eastward. Some of the lowest temperatures were noted in Wisconsin and Michigan, where readings below 30°F were common. Freezes are a concern with respect to fruit crops in Michigan, although development was as much as 1 to 2 weeks behind normal due to persistently cool spring weather.

In the South, cool but dry weather favors planting activities and other spring fieldwork. However, scattered frost was noted this morning across the interior Southeast, including parts of Kentucky and Tennessee.

Outlook: Warmth over the western and central U.S. will expand eastward, encompassing much of the nation by mid-week. Toward week’s end, cooler weather will overspread the West, while warmth will be especially notable across the High Plains. Showers will return to the Midwest during the mid- to late-week period, where 5-day rainfall totals could exceed an inch in some locations. Elsewhere, locally heavy precipitation (1 to 2 inches) will affect the Northwest, while little or no rain will fall in the southern Atlantic region and from California to the southern High Plains. The NWS 6- to 10-day outlook for May 18-22 calls for below-normal temperatures across the Plains and Deep South, while warmer-than-normal weather will prevail in much of the eastern and western U.S. Meanwhile, below-normal precipitation across the southern Plains and the West will contrast with wetter-thannormal conditions along and northeast of a line from Montana to Georgia.