ACUS02 KWNS 110555 SWODY2 SPC AC 110553 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1253 AM CDT Mon May 11 2026 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF SOUTHEAST KANSAS AND FAR NORTHEASTERN OKLAHOMA NORTHEASTWARD INTO NORTHERN ILLINOIS...NORTHWEST INDIANA AND FAR SOUTHEAST WISCONSIN... ...SUMMARY... Isolated severe storms with strong wind gusts and hail will be possible on Tuesday from parts of southeast Kansas and far northeastern Oklahoma northeastward into northern Illinois, northwest Indiana and far southeast Wisconsin. ...Central Plains/Mid Mississippi Valley/Southwest Great Lakes... At mid-levels, a shortwave trough and an associated jet streak will move southeastward through the Upper Midwest on Tuesday. At the surface, a low will move southeastward across Wisconsin as a cold front advances southeastward into the mid to upper Mississippi Valley. Thunderstorms are expected to develop near the front in the afternoon as surface heating takes place and low-level convergence becomes more focused. The storms are forecast to move toward an instability axis located from southeast Kansas to north-central Illinois. Along this axis of instability, MLCAPE is forecast to increase into the 500 to 1500 J/kg range by late afternoon with 0-6 km shear mostly in the 45 to 55 knot range. Low-level lapse rates are also forecast to become steep just ahead of the front. This environment should be sufficient for an isolated severe threat, with hail and strong wind gusts possible. The strongest instability and steepest mid-level lapse rates are forecast to be further southwest into parts of southwest Missouri and southeast Kansas, where a locally greater hail threat will be possible in the late afternoon. ..Broyles.. 05/11/2026 $$