USDA's Joint Ag Weather Facility says on the Plains, hot, dry weather favors summer crop maturation but is maintaining severe stress on rangeland and pastures. "Today's high temperatures could exceed 100°F as far north as southern South Dakota," USDA reports.
In the West, USDA says widely scattered showers extend northward from Arizona. "Cool conditions are limited to areas along the Pacific Coast," USDA adds. Elsewhere, late-season heat favors small grain harvesting and other fieldwork, according to USDA.
In the Corn Belt, USDA says a band of showers stretches from the lower Great Lakes region into the middle Mississippi Valley. "The rain is too late for many summer crops, especially corn, but is helping to revive pastures," USDA reports.
In the South, USDA reports Tropical Storm Isaac is bearing down on the central Gulf Coast, a day after lashing southern Florida with rain squalls and gusty winds. "At 8 a.m. EDT it was centered 360 miles southeast of the mouth of the Mississippi River, moving toward the west-northwest at 14 mph. Maximum sustained winds are near 65 mph," USDA explains. Locally heavy showers continue across Florida’s peninsula, but warm, dry weather covers the remainder of the South, according to USDA.
In its outlook, USDA says Isaac should strengthen and is expected to be a hurricane at landfall on the central Gulf Coast late Tuesday or early Wednesday. "Due to some uncertainty in Isaac’s track, hurricane warnings have been issued along the Gulf Coast from the south-central Louisiana to western Florida, including New Orleans," USDA explains. In addition, Isaac should be a prolific rain-maker in the lower and middle Mississippi Valley, according to USDA. "Along and near the storm’s path, rainfall could reach 6 to 12 inches, with isolated amounts in excess of 18 inches," USDA says. 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, according to USDA.