In the West, warmth is returning to the Pacific Coast States and northern Rockies. However, cool conditions prevail elsewhere, including the Intermountain West and the central and southern Rockies. Lingering showers are confined to the central Rockies and northern Intermountain West; dry weather elsewhere favors fieldwork.

On the Plains, heavy showers are maintaining the threat of flooding across the northern tier of the region, primarily in North Dakota and eastern Montana. Elsewhere, cool air has spread as far south as the central High Plains, while hot weather persists in much of Texas. On Sunday, high temperatures climbed to 101°F in Texas locations such as San Angelo and Wichita Falls.

In the Corn Belt, corn and soybean planting activities have been slowed or halted by showers and locally severe thunderstorms, except in Indiana, Michigan, and Ohio. Several twisters were reported in Iowa on Sunday, ending a state-record stretch of tornado-free weather at 359 days (May 25, 2012 – May 18, 2013). Currently, heavy rain is falling in several areas, including the middle Mississippi Valley and the far upper Midwest.

In the South, scattered showers and thunderstorms are mostly confined to the southern Atlantic States. Elsewhere, warm, dry weather favors fieldwork, including cotton, rice, and soybean planting.

Outlook: A powerful, slow-moving storm currently centered over eastern South Dakota will drift eastward and gradually weaken, reaching the lower Great Lakes region by mid-week. The storm’s remnant circulation will cross northern New England on Thursday. Additional rainfall associated with the storm could reach 1 to 3 inches from North Dakota to Maine. Thunderstorms along the storm’s trailing cold front could be severe, especially later today across the southeastern Plains and the Mid-South. During the second half of the week, a new storm will begin to take shape across the Northwest, resulting in above-normal temperatures on the Plains, along with the threat of thunderstorms. The NWS 6- to 10-day outlook for May 25-29 calls for above-normal temperatures nationwide, except for cooler-than-normal conditions in the Far West and along and near the Atlantic Seaboard. Meanwhile, near- to below-normal precipitation across the majority of the U.S. will contrast with wetter-than-normal weather in the southern Atlantic region and across the nation’s northern tier from Washington to Minnesota.