In the West, cool weather is confined to areas along the Pacific Coast. Elsewhere, hot, mostly dry weather is promoting crop maturation and fieldwork, including Northwestern small grain harvesting. During the week ending August 26, the spring wheat harvest passed the halfway mark in Idaho (66% complete) and Washington (63%).

On the Plains, showers are confined to parts of the eastern Dakotas. Elsewhere, hot, dry weather favors summer crop maturation and fieldwork, but is maintaining or increasing stress on rangeland and pastures. For the second consecutive day, high temperatures will reach or exceed 100°F as far north as South Dakota.

In the Corn Belt, mostly dry weather accompanies a late-season warm spell. Scattered showers are confined to the upper Midwest. On August 26, Missouri led the nation with 99% of its pastureland rated in very poor to poor condition, followed by Nebraska with 95%.

In the South, Tropical Storm Isaac is bearing down on the central Gulf Coast, while locally heavy showers are affecting the southern Atlantic region. At 8 a.m. EDT, Isaac was centered 105 miles south-southeast of the mouth of the Mississippi River, moving toward the northwest at 7 mph. Sustained winds are near 70 mph.

Outlook: Isaac should continue to strengthen and is expected to be a hurricane at landfall on the central Gulf Coast late Tuesday. Hurricane warnings are in effect along the Gulf Coast from Morgan City, Louisiana to the Alabama- Florida border, including New Orleans. In addition, Isaac should be a prolific rain-maker in the lower and middle Mississippi Valley and across the lower Midwest. Along and near the storm’s path, rainfall could reach 7 to 14 inches, with isolated amounts near 20 inches. Little or no rain will occur through week’s end across the remainder of the U.S., while a late-season heat wave will expand from northern portions of the Rockies and Plains into the Midwest and Northeast. The NWS 6- to 10-day outlook for September 2-6 calls for warmer-than-normal weather nationwide, except for near- to below-normal temperatures in the Pacific Coast States. Meanwhile, drier-thannormal conditions in Texas and in most areas from the Pacific Coast to the Rockies will contrast with above-normal rainfall across the central Plains, Midwest, and much of the East.