USDA's Joint Ag Weather Facility (JAWF) notes that showers and thunderstorms returned to the upper Midwest, maintaining unfavorably wet field conditions. Due to heavy overnight rainfall, flash flood warnings are in effect across portions of the upper Mississippi Valley. In contrast, very warm, dry weather covers the southern Corn Belt.
On the Plains, JAWF says cool, showery weather is confined to areas along and near the Canadian border, from Montana into North Dakota. "Farther south, warm, dry weather continues to promote summer crop maturation and harvesting, along with winter wheat planting," it states. "In Kansas, 9% of the intended winter wheat acreage was planted by Sept. 18, while harvesting was underway for corn (17% harvested), sorghum (5%), and cotton (2%)."
In the West, former Hurricane Paine has dissipated before reaching northwestern Mexico, but associated tropical moisture is sparking a few showers in the southwestern United States, says JAWF. "Meanwhile, a separate weather system is arriving in the Northwest, bringing cooler conditions and isolated showers," it states.
In the South, a weak low-pressure system that was once Tropical Storm Julia continues to produce rain in southeastern Virginia and portions of the Carolinas, states JAWF. "A few showers also linger across Florida’s peninsula," it states. "Elsewhere, hot, dry weather favors fieldwork but is increasing stress on pastures and immature summer crops."
In its outlook, JAWF says rainfall in the southern Mid-Atlantic region will gradually subside as the remnants of Tropical Storm Julia drift offshore. "Farther west, locally heavy showers and thunderstorms will persist into Thursday across the upper Mississippi Valley, where more flash flooding can be expected," it states. "Meanwhile, a developing storm system over the western U.S. will result in heavy precipitation (locally 2 to 6 inches) from the northern Intermountain West to the northern High Plains. During the weekend, showers and thunderstorms will erupt across the Plains and upper Midwest, resulting in additional rainfall totals of 1 to 3 inches. Cooler air will trail the storm across the western and central U.S. but temperatures will quickly rebound to above-normal levels in the Far West by early next week."