The nation’s weather

Weather Underground Forecast for Thursday, July 21, 2016

A low pressure system will bring active weather to the Midwest on Thursday, while monsoonal thunderstorms fire up across the Southwest.

An area of low pressure will move eastward over the upper Great Lakes. This system and a cold frontal boundary will produce showers and thunderstorms across the northern Plains, the upper Mississippi Valley and the Midwest. Severe thunderstorms will be possible in eastern Wisconsin and Michigan. These thunderstorms will be capable of producing large hail, dangerous straight line winds and isolated tornadoes.

Just to the south, moisture-rich air will lead to the development of showers and isolated thunderstorms across the Deep South, the Southeast and the southern Mid-Atlantic. Most of the northern Mid-Atlantic and New England will experience dry conditions.

Out west, monsoonal moisture will surge across the Four Corners. Daytime heating will trigger isolated showers and thunderstorms across the region. A ridge of high pressure will keep hot and dry weather in place over the central and southern Plains.

Meanwhile, a weak area of low pressure along the coast of the Pacific Northwest will stir up scattered showers and thunderstorms over Oregon and Washington. The remainder of the West Coast will stay clear of precipitation. Temperatures are forecast to climb above 110 degrees across parts of the Desert Southwest on Thursday.

Temperatures in the Lower 48 states Wednesday have ranged from a morning low of 32 degrees at Truckee-Tahoe, Calif. to a high of 107 degrees at Yuma MCAS, Ariz.