A low pressure system over the Dakotas will continue to strengthen and advance eastward Wednesday, producing widely scattered showers and thunderstorms from the Upper Midwest and Great Lakes southwestward through the Central Plains.
In particular, there is a slight risk of severe thunderstorms across the Upper Mississippi River Valley and Central Plains. These storms are possible producing severe hail and damaging winds Wednesday afternoon and evening.
In the East, a cold front is expected to become nearly stationary over the Carolinas and Southeast on Wednesday and Thursday. Showers and thunderstorms are likely to develop along and south of the frontal boundary. The Northeast, however, will dry out by Wednesday morning, except far northern Maine. High pressure will build after the low pressure system, providing mostly sunny skies with highs ranging from upper 70s to upper 80s.
Little relief is anticipated from the recent heat across much of the southern Great Plains and Southwest. Temperatures are expected to climb back to the upper 90s and 100s once again with locally higher readings. A temporary relief is possible as the monsoonal showers and thunderstorms occur. Otherwise, it will remain hot over the next few days.
Temperatures in the Lower 48 states Tuesday ranged from a morning low of 32 degrees at Truckee-Tahoe, Calif., to a high of 108 degrees at Vernon, Texas.