The Central U.S. will see another hot day Tuesday, while scattered showers and thunderstorms persist along the Ohio River Valley, Midwest and Central Plains.
A low pressure system moving through eastern Canada will continue pulling warm and moist air into the Eastern U.S. from the Gulf of Mexico, while flow behind this system will bring cooler air in from central Canada. This will push a cold front over the Great Lakes and into the Midwest. The northern edge of this front will kick up scattered showers and thunderstorms over the Northeast and New England, while the tail end of this system will reach into the Central Plains, also producing showers and thunderstorms. This system has a history of creating severe thunderstorms with strong winds, large hail and even tornadoes. If these storms turn severe, they will most likely develop along the Ohio River Valley. Additionally, this front will bring some relief to the hot conditions across the Midwest. While highs were up to 100 degrees in the Midwest on Monday, they will remain in the 90s on Tuesday. The South, however, will see little cooling as the cold front remains to the north. Expect the Southern Plains, Lower Mississippi River Valley, and Southeast to remain under heat advisories as high temperatures will reach near 100 degrees, with heat indicies ranging from 110 to 120 degrees.
In the West, a trough of low pressure moves over the West Coast, bringing cool and moist air onshore with it. This will kick up scattered showers over the Pacific Northwest. Meanwhile, monsoon moisture over the Southwest will trigger thunderstorms over New Mexico and the Four Corners. Flash flooding is likely as these storms will produce periods of heavy downpours.
Temperatures in the Lower 48 states Monday have ranged from a morning low of 32 degrees at Truckee, Calif., to a high of 104 degrees at Bastrop, La.