A complex of rain and thunderstorms are expected to spread from out of the mid-Mississippi Valley tonight into the Ohio Valley and western Great Lakes by early tomorrow.
Behind this activity, a cold front and upper trough will spread eastward with severe thunderstorms developing in the afternoon.
The greatest chance for severe storms Wednesday into Wednesday night extends from southern Wisconsin and southwestern Michigan southwestward to Illinois, Indiana, Missouri and the southeastern halves of Kansas and Iowa into Oklahoma. This includes cities such as St. Louis, Mo., Chicago, Ill., Davenport, Iowa, Springfield, Mo. and Tulsa, Okla. Damaging winds, large hail and tornadoes will all be possible.
In addition to the severe threat, heavy rain will accompany the front with some locations picking up 2 or more inches of rainfall.
Strong winds gusting to 55 mph in some locations are expected behind the storm throughout the Plains. Gusty winds (but not as strong as the Plains) are also expected ahead of the front from the mid-Mississippi Valley to the Great Lakes.
High temperatures will range from the chilly 40s and 50s in northern South Dakota and North Dakota to the 70s and 80s stretching from Kansas to the mid-Mississippi Valley.