In the West, very cool weather is hampering crop development. In addition, high winds are raking parts of the Southwest, while locally heavy rain and snow showers are falling across the Intermountain West.

On the Plains, a late-season snow storm is underway in Wyoming, northeastern Colorado, and western portions of South Dakota and Nebraska. Meanwhile, portions of the central and southern Plains are contending with high winds and the after-effects of locally severe thunderstorms.

In the Corn Belt, very cool weather continues to limit the emergence and development of recently planted corn and soybeans. Somewhat warmer conditions, accompanied by showers and thunderstorms, exist across the southern Corn Belt.

In the South, mild, mostly dry weather favors fieldwork and crop development in most areas, although cool, cloudy conditions linger east of the Appalachians.

Outlook: A large, complex storm system will generate additional late-season snow in the central Rockies, while a mixture of rain and snow falls from the central High Plains into the Dakotas and Upper Midwest. Locally heavy showers and thunderstorms will develop along a trailing cold front over the southern Plains, mid-South, and Corn Belt, although rain will become light and scattered as the front reaches the Southeast and Gulf Coast. The combination of Gulf moisture and the front becoming stationary may trigger heavy downpours over the southern Plains by week’s end. Drier, increasingly warmer weather will return to much of the West, with the next Pacific storm expected to arrive in the Northwest early next week. The NWS 6- to 10-day outlook for May 17-21 calls for near- to above-normal temperatures across the central one-third of the U.S., while cooler-than-normal conditions will prevail in the Pacific and Atlantic Coast States. Meanwhile, below normal precipitation in the Great Lakes States will contrast with wetter-than-normal weather in a broad swath from the Northwest into the Southeast.