Weather Underground Forecast for Tuesday, July 14, 2015

A wave of pressure will slide across the Midwest on Tuesday, while a trough of low pressure will shift over the Northwest.

A wave of low pressure will move east southeastward over the Ohio Valley. A strong onshore flow from the Gulf of Mexico will push warm, muggy air across the Southeast and the Mid-Atlantic. The wave of low pressure will collide with this air mass, producing widespread strong to severe thunderstorms across the eastern third of the country. Severe thunderstorms will be possible in southeast Indiana, southern Ohio, West Virginia, Kentucky, southern Virginia, Tennessee, North Carolina, South Carolina, northern Georgia, northern Alabama and northeast Mississippi. These thunderstorms will be capable of producing large hail, dangerous straight line winds and isolated tornadoes. Heavy rain will bring threats of flash flooding to eastern Tennessee, eastern Kentucky, western Virginia, West Virginia, eastern Ohio, Pennsylvania, Maryland and southwest New Jersey.

Meanwhile, monsoonal moisture will surge across the Four Corners, bringing chances of showers and thunderstorms to the region. Just to the north, a trough of low pressure will move slowly eastward over the Pacific Northwest and the upper Intermountain West. Isolated showers and thunderstorms will fire up over parts of the Cascades, the Great Basin and the Rockies. High pressure will keep conditions quiet across California on Tuesday. Temperatures will spike into the triple digits across the Desert Southwest.

Temperatures in the Lower 48 states Monday have ranged from a morning low of 35 degrees at Truckee-Tahoe, Calif. to a high of 100 degrees at Dodge City, Kan.