Severe thunderstorms are possible, mainly late this afternoon into this evening and tonight, within the yellow shaded areas on the image above. Large hail and damaging winds will be the primary threats. A few tornadoes also cannot be ruled out, especially as activity initially develops this evening. An enhanced risk of large hail will exist within the red shaded and black hatched areas on the image below:
An upper-level weather disturbance will move East into the central Plains and Midwest this afternoon & evening. At the surface, the atmosphere will become very unstable, with a strong capping inversion in place which will initially inhibit thunderstorm development until late afternoon & early evening. Once thunderstorms develop, they will quickly become severe.
The most likely area for initial development late this afternoon and early this evening will be within the red shaded and black hatched region on the image above. As thunderstorms initially form within this region, they are likely to be supercells, with large hail, damaging winds and a few tornadoes possible. As the activity moves and/or develops to the Southeast during the late evening and overnight hours, damaging winds will become the primary threat as the activity is expected to congeal into a large complex of thunderstorms.
At this time it is unclear how far to the Southwest thunderstorms will be able to develop this evening. The cap will be very strong across southeast Kansas and northeast Oklahoma. Any thunderstorm that is able to form in this area would likely be isolated but quickly become severe, with very large hail and damaging winds the primary threats.
If you live in any of the above mentioned areas, please remain alert this afternoon & evening and be prepared to seek shelter if threatening weather approaches your area.
If you live across southern Illinois, southeast Missouri and adjacent portions of Kentucky, Tennessee and into adjacent portions of the Mississippi Valley, please be aware that severe thunderstorms may move into your region after dark tonight. It would be a good idea to have a programmable NOAA Weather Radio or some other means of receiving nighttime warnings should severe weather threaten your area.