A front extending from the upper Great Lakes across the Ohio Valley to the Central Plains will sink southward to the Carolinas and off the Northeast/Mid-Atlantic coast by Wednesday morning. Showers and thunderstorms will develop along and ahead of the front from the Northeast to the upper Mississippi Valley and will advance into the Mid-Atlantic/off the Northeast coast by Tuesday evening.
Very moist air and upper-level disturbances will produce scattered showers and thunderstorms from the central to eastern Gulf Coast. Monsoonal moisture and afternoon heating will produce showers and thunderstorms over the Southern/Central Rockies on Tuesday afternoon and evening.
There is a slight risk of severe thunderstorms from the Carolinas and Mid-Atlantic Region northwestward into the Ohio Valley and northern Plains. Yesterday, there were over 180 reports of high wind and hail mostly from in New England, Virginia, the Carolinas, the Wisconsin, Illinois border area, South Dakota and Nevada.
Under a strong ridge of high pressure, temperatures in the 90s to the low 100s are possible from the Midwest into the Mid-Mississippi Valley and parts of the Southern Plains. The high temperatures combined with humidity has resulted in Excessive Heat Warnings and Heat Advisories being issued by local Weather Forecast Offices. Heat Advisories are also in effect from Tidewater Virginia, across coastal North Carolina, into the Pee Dee region of South Carolina.