A complex of damaging thunderstorms will develop across parts of northern Minnesota and northern Wisconsin this afternoon and evolve perhaps into a Derecho tonight. During the first 6 hours of the development, the impacts will be damaging winds and tornadoes. The rotation tracks suggest a few damaging tornadoes could develop prior to the system forming into an Derecho. Once the Derecho forms, it will head southeast into the Ohio and Indiana tonight and Thursday morning. A swath of wind damage will occur due to winds over 60 mph. The system may impact Greenbay, Grand Rapids and Detroit. Chicago and Milwaukee could be skirted by the Derecho tonight. The Derecho will go all the way to western PA and West Virginia by Thursday midday.
Day 2 – A secondary severe weather outbreak will occur from Ohio into Pennsylvania, Maryland and Northern Virginia Thursday. That area will see storms with damaging winds and hail. A tornado risk may occur across Ohio into Western PA.