2AM Day 3 Convective Outlook for Wednesday, July 16. THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL PLAINS TO THE MID-MISSISSIPPI VALLEY VICINITY
SUMMARY
Scattered strong to severe thunderstorms are possible Wednesday afternoon and evening from parts of eastern Wyoming and Colorado into Illinois and Wisconsin.
Central Plains to Mid-MS Valley Vicinity
A shortwave upper trough and likely MCV from Day 2/Tuesday convection will move across MN/WI and the Great Lakes on Wednesday. Another upper trough over the northern Rockies will shift east across the northern/central Plains. These two features will result in enhanced westerly flow atop a moist and moderate to strongly unstable boundary layer from the central High Plains toward the Great Lakes. Meanwhile, a cold front/composite outflow (related to Day 2/Tuesday storms) will percolate southeast across the Upper Midwest and central Plains.
Uncertainty exists regarding location of key surface boundaries/MCVs, as these features will be tied to convective evolution in the Day 2/Tuesday period. Nevertheless, a very moist and unstable airmass and favorable vertical shear should support scattered strong to severe thunderstorms ahead of the surface front. Additional strong storms are possible in the post-frontal upslope flow regime across parts of eastern WY/CO. As the location of key features become more certain in the coming couple of days, the outlook area may shift and/or upgrades may become necessary.