Heads up if you are outdoors: Canadian wildfire smoke is triggering widespread air quality alerts across the Great Lakes and Midwest today, Monday, July 20. Expect another thick plume of smoke to push south on Tuesday behind the cold front.
MULTIPLE TORNADOES are possible today across the Midwest, with the SPC upgrading today's risk to a large 10% CIG 1!
This means a couple of EF-2+ tornadoes are possible across Iowa, Illinois, Wisconsin, and Minnesota. We will be LIVE covering this!
SPC just pushed today's tornado odds from 5% up to 10% over Wisconsin, Iowa, and Minnesota, still inside the same Level 3 zone from this morning. Charles City, Decorah, and Oelwein, IA sit right in that highest-odds bullseye, with storms expected to fire back up between 3 and 9 PM and the roughest stretch landing close to 6. A couple of these could turn into real tornado producers, not just quick spin-ups. Coverage looks likely to come on this evening as things peak near 8.
If a tornado forms anywhere in the country tomorrow, Madison, WI, Charles City, IA, and Decorah, IA are the top candidates. SPC has that area at a Level 2 for tornadoes, the highest tier out for Monday.
A dual threat setup controls todays forecast, driven by a sagging front in the East and a digging Canadian shortwave for the northern Plains.
Southeastern US - High precipitable water values and strong heating will yield some instability, with steep lapse rates in the lower levels allowing for wet microbursts, posing primarily a damaging wind threat.
Dakotas/Minnesota - Initial discrete supercells fueled by decent shear and straight hodographs will lead to the threat of very large hail (greater than 2"), with supercells transitioning into clusters that will produce a destructive wind threat through the evening.
Tropical development is possible near Florida this weekend. Invest 91L has a 40% chance of development over the next few days and could bring flooding rainfall to the Gulf Coast, in addition to gusty winds.