Posted June 28, 2018 11:11 p.m. EDT
A mass of dry air will provide sunshine and moderate humidity Friday from the eastern Great Lakes to southern New England and the Mid-Atlantic. Rain is expected to move out of Maine.
Showers and thunderstorms are in the forecast from the lower Ohio and middle Mississippi valleys to the northeast Gulf and Southeast coasts. The combination of steamy air and storm systems moving along a nearby temperature and humidity contrast zone will produce the stormy conditions.
From the Plains to much of the Midwest, a heat wave will reach its peak this weekend. Highs will be well into the 90s, with temperatures reaching 100 degrees in parts of the central and southern Plains. The high temperatures, humidity, sunshine and other factors will make it feel 10 to 20 degrees hotter in the afternoon. A few strong thunderstorms will affect the northern Plains and the Upper Midwest.
Much of the West can expect sunshine. A storm near the Canadian border will produce showers and thunderstorms from northern Washington to the northern Rockies. A light breeze from the Pacific Ocean will bring morning low clouds and cooler conditions to the West Coast beaches.
FOCUS: Possible Severe Thunderstorms on Saturday
The leading edge of a cooler and less humid air mass is expected to bring strong to severe thunderstorms over parts of the Upper Midwest on Saturday afternoon and evening. Parts of eastern Minnesota, Wisconsin and Iowa may be affected.