In the West, very warm weather prevails, except for some lingering coolness in the southern Rockies. Dry conditions are causing some producers to refrain from winter wheat planting, especially in Idaho and Oregon. Meanwhile, wheat planting has passed the halfway mark in Washington, and was 60% complete by Sep. 16.

On the Plains, winter wheat planting remains behind the 5-year average pace in all seven of the region’s major production states. Progress is more than 10 percentage points behind the average in Colorado, Nebraska, and South Dakota. Meanwhile on the southern Plains, where topsoil moisture has improved in recent days—to the benefit of rangeland, pastures, and newly planted winter grains—a few thunderstorms persist.

In the Corn Belt, rain is slowly ending across eastern portions of the region. During the last 24 hours, most of the Midwest has received some rain, although totals were generally less than an inch. In the rain’s wake, cool weather prevails. A freeze was noted early today across much of northern Minnesota, and frost advisories are in effect this morning for parts of the eastern Dakotas, southwestern Minnesota, and northwestern Iowa.

In the South, heavy rain is causing localized flooding in the Tennessee Valley and the central and southern Appalachians, where some Sep. 17-18 precipitation totals have already exceeded 4 inches. Currently, heavy rain is sweeping into the Southeast, halting fieldwork and causing flash flooding.

Outlook: For the remainder of today, heavy rain will affect the East, with additional totals of 1 to 3 inches possible. Rain will largely end by Wednesday, except for lingering showers along the Atlantic Seaboard and a few rain squalls in the vicinity of the Great Lakes. Frost can be expected in the Great Lakes region on Wednesday morning, and another surge of cool air will result in additional frost across the upper Midwest toward week’s end. In contrast, unusually warm weather will prevail during the next several days in the West, occasionally reaching the High Plains. The NWS 6- to 10-day outlook for September 23-27 calls for cooler-than-normal conditions in much of the eastern half of the U.S., while above-normal temperatures will cover most areas from the High Plains westward. Meanwhile, near- to below-normal precipitation across the majority of the U.S. will contrast wetter-than-normal weather in the southern Atlantic region and from the lower Great Lakes region into the Northeast.