Across the Corn Belt, a band of rain generally stretches from Nebraska to Michigan. The rain is benefiting immature summer crops, including some soybeans, but nearly two-thirds (63%) of the U.S. corn had already dented by August 30. Sharply cooler air is arriving across the upper Midwest. In fact, freezes were reported this morning in parts of North Dakota, where only 26% of the corn had dented by late August.
On the Plains, a cold front is punching southward. Lingering warmth is confined to Oklahoma and Texas. Farther north, snow is blanketing an area centered on northeastern Colorado, southeastern Wyoming, and western Nebraska, while freezes have ended the growing season in parts of North Dakota, Montana, and Wyoming. Early Monday, precipitation is boosting topsoil moisture in Nebraska and environs, benefiting rangeland but arriving too late for many summer crops.
In the South, warm, mostly dry weather favors summer crop maturation and harvesting. Rain showers are confined to parts of the western Gulf Coast region and scattered locations along the southern Atlantic Coast.
In the West, a stunning array of weather, ranging from heavy snow in Wyoming to uncontrolled wildfires in parts of California, mark the transition to autumn. With drought covering more than two-thirds (67.6%) of the West, according to the U.S. Drought Monitor, conditions remain ripe in the Great Basin and Pacific Coast States—amid gusty winds and low humidity levels—for further wildfire ignition and expansion. The dangerous Creek Fire, northeast of Fresno, California, has torched some 80,000 acres of timber and chaparral. In southern California, Sunday, September 6 was the hottest day ever recorded in locations such as Woodland Hills (121°), Paso Robles (117°), and San Luis Obispo (117°).
An unusually strong, early-autumn cold outbreak will engulf the Plains, Midwest, and interior sections of the West. Mid-week freezes may occur as far south as the central High Plains (e.g. eastern Colorado) and as far east as the far upper Midwest (e.g. North Dakota and northern Minnesota). Late in the week, however, effects of the cold spell will wane, with above-normal temperatures quickly returning across the Northwest. Meanwhile, warmth will continue throughout the week in the Southeast. In part due to the sharp temperature gradient in place during the next several days, heavy rain (locally 2 to 5 inches or more) can be expected from the southern Plains into the upper Midwest. Heavy showers may also occur along and near the southern Atlantic Coast. In contrast, dry weather will persist across the Far West.
Looking ahead, the 6- to 10-day outlook calls for the likelihood of near- or below-normal temperatures across the Plains, Midwest, Northeast, and mid-South, while warmer-than-normal weather will prevail in the West and Southeast. Meanwhile, near- or below-normal precipitation across much of the country should contrast with wetter-than-normal conditions in large sections of the Gulf and Atlantic Coast States.