In the West, cool air continues to spread inland, although warm, dry weather continues to promote cotton harvesting and other fieldwork in the Desert Southwest. Rain and snow showers are increasing in coverage and intensity across the northern Rockies and northern Intermountain West.

On the Plains, cool, rainy weather is overspreading the western half of Montana. Elsewhere, mild weather favors summer crop maturation and winter wheat planting and emergence, although producers in the Red River Valley continue to monitor immature crops in the wake of Tuesday’s light freeze.

In the Corn Belt, frost was noted this morning in much of Wisconsin and parts of Minnesota and northern Iowa. In frost-affected areas, temperatures mostly in the range of 30 to 35 degrees F may have frozen some of the leaf canopy in fields of immature corn and soybeans, but were generally not low enough to end the 2009 growing season.

In the South, dry weather continues to promote a limited return to fieldwork—including rice, cotton, and soybean harvesting —following an extended period of unfavorable wetness.

Outlook: The NWS has issued a frost advisory for Thursday morning from central and southern Lower Michigan into much of Ohio and West Virginia. For the remainder of the week, a slow-moving storm will spark widespread rain across the northern half of the U.S. Late-week rainfall could total 1 to 3 inches in the upper Midwest. Meanwhile, showers and thunderstorms along the storm’s trailing cold front will produce briefly heavy rain across the South. By week’s end, a second storm will arrive in the West, resulting in a continuation of cold, unsettled weather. The NWS 6-to 10-day outlook for October 5-9 calls for above-normal precipitation across the Plains and Midwest, while drier-than-normal weather will prevail in the lower Southeast and the Pacific Northwest. Meanwhile, below-normal temperatures from the Southwest to the northern Plains will contrast with warmer- than-normal conditions in the East and the Pacific Northwest.

Weather Report: Frost In Minnesota, Wisconsin & Northern Iowa, Dry In The South