Possible severe weather around midweek.

[nWo]

On Wednesday, an upper low over the Upper Midwest will move across the Great Lakes and into Ontario to the east and northeast. There will be a sustained strengthened mid/upper southwesterly flow over a large section of the region. Strong low pressure over Minnesota and Wisconsin will occlude at the surface and gradually turn northeasterly and north into Ontario. A cold front is expected to move eastward over Lower MI, IL, and IN, while the boundary's southernmost point either stalls or moves slightly northward from southern MO into Oklahoma and northwest Texas. Along the cold front, convection might still be going on Wednesday morning. During the day, destabilization would be happening ahead of the boundary across the Ohio Valley. Convective evolution is less certain further south. Nonetheless, an extremely humid and erratic airmass is anticipated. It is possible for thunderstorms to continue during the morning and continue. There is still some doubt about the specifics, but given the existence of a surface boundary, enough vertical shear, and a moist/unstable boundary layer, a corridor of severe potential seems likely. 
 

With this information, The Storm Prediction Center has sections of Kentucky, WKY along the Ohio River to the Cincinnati area, with a % chance of strong to severe storms on Wednesday.

 

 

[nWo]

On Wednesday, there is a chance of severe thunderstorms with hail and destructive gusts from northern Texas to the Ohio Valley and lower Great Lakes region. Large to extremely large hail and damaging gusts are most likely to occur from north Texas to the Missouri Bootheel area.

 

The eastward-moving cold front and any MCVs from Tuesday's leftover convection on Day 1 will be the main factors causing the ascent in the area. These will be floating in the southwesterly flow. Over IN, OH, and KY, there will be a humid airmass with mid-to upper-60s dewpoints. This airmass will stretch northeast into NY/PA and the neighboring states in the low- to mid-60s. In the late morning and afternoon, moderate instability will be facilitated by a plume of steep midlevel lapse rates and significant heating. Cells that are organized will only need a minimal amount of vertical shear. Small hail and intermittently strong gusts of destruction are possible during thunderstorms.