A storm system over the Upper Mississippi Valley will move eastward to the lower Great Lakes by Thursday evening. Showers and thunderstorms will develop along and ahead of the associated warm front from the Upper Mississippi Valley to the Ohio Valley moving into the Great Lakes and the Northeast by Thursday. Showers and thunderstorms will also develop along the cold front from the Upper Mississippi Valley to the Central Plains moving to the Ohio Valley and extending southwestward to the Southern Plains.
Moisture rich air and upper-level disturbances will trigger showers and thunderstorms along the eastern/central Gulf Coast through Thursday. Monsoonal moisture and afternoon heating will produce showers and thunderstorms over the Southern Rockies and parts of the Central Rockies mainly in the afternoon and evening hours of Wednesday and Thursday.
There is a slight risk of severe thunderstorms from portions of the central Plains eastward to the upper Midwest and Great Lakes. Yesterday, there were over 260 reports of high wind and hail mostly from the Carolinas, Mid-Atlantic, New England, Ohio Valley, and northern Plains.
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. 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 across parts of Alabama, Mississippi, and Georgia.
The National Weather Service in Kansas City/Pleasant Hill has issued a red flag warning for all of northern Missouri, as well as much of middle Missouri and adjacent far eastern Kansas. This warning is in effect from noon until 7pm CDT this evening. Increasing southwest winds will become strong and gusty this afternoon in conjunction with a very hot and dry air mass already in place.