In the West, abundant tropical moisture continues to affect the Four Corners States, providing drought relief but triggering local flooding. In contrast, hot, dry weather prevails in northern California and the Northwest, promoting summer crop maturation and fieldwork, including winter wheat planting.

On the Plains
, hot, dry weather prevails across northern and eastern portions of the region. However, cooler air is overspreading the central High Plains, accompanied by scattered showers. The rain is slowing fieldwork but providing beneficial topsoil moisture for the upcoming winter wheat establishment season.

In the Corn Belt, the passage of a cold front is introducing slightly cooler air into the upper Midwest, although temperatures remain above normal. Isolated showers are occurring in the vicinity of the cold front, but unfavorably dry weather continues to adversely affect immature corn and soybeans.

In the South, warm, generally dry weather continues to promote summer crop maturation and harvesting. Dry weather remains favorable in the Southeast, but drought continues to develop from the Delta westward.

Outlook: A cold front crossing the Midwest will provide relief for many areas from late-season heat. However, hot weather will linger through week’s end across the Deep South, and persist into next week across the northern High Plains, Pacific Coast States, and Northwest. Meanwhile, a late-summer monsoon surge will maintain the threat of flooding in the Four Corners States. During the next 5 days, some of the heaviest rain—possibly 2 to 5 inches— will fall from the southern Rockies to the central High Plains. In the latter region, rain will slow fieldwork but provide much-needed moisture for newly planted winter wheat. In contrast, only light showers can be expected in the parched Midwest. Elsewhere, 1- to 3-inch rainfall totals may occur during the next 5 days in the Northeast and southern sections of Florida and Texas. In particular, development of a tropical cyclone could occur toward week’s end over the southwestern Gulf of Mexico. The NWS 6- to 10-day outlook for September 16-20 calls for near- to above-normal temperatures and rainfall across the majority of the nation. Cooler-than-normal conditions will be limited to the Mid-Atlantic coastal plain, while drier-than-normal weather will be confined to the Northeastern and Mid-Atlantic States.