Severe Thunderstorms Are Possible in the Northern U.S. This Week

Pumpkin spice, cooler air, and angry election ads proclaiming the end of the world—it sure feels like fall, but the weather doesn’t always agree. A potent cold front will sweep across the northern United States and southern Canada through the middle of the week, potentially triggering severe thunderstorms along its path.

The Storm Prediction Center‘s forecasts on Monday showed a slight risk for severe thunderstorms in the Great Lakes and Midwest during the day on Tuesday, with the severe threat moving into the Northeast on Wednesday. The maps stop at the border—there are sovereignty and tax-dollar issues preventing most government weather maps from extending into Canada—but you can use your imagination to fill in the missing lines that extend into southern parts of Ontario and Quebec.

The pattern is a classic fall severe weather setup. A strengthening low-pressure system will cross the Great Lakes into eastern Canada over the next couple of days, dragging down cooler and less-humid air behind it. The cold front, digging into warm-ish and muggy-ish air to the south, will trigger lines of severe thunderstorms, some of which could be severe with damaging wind gusts, large hail, and isolated tornadoes.

The SPC mentioned in its afternoon update on Monday that the risk in some areas on Tuesday could be upgraded to an enhanced risk—a three out of five on the scale measuring the severe weather risk—if it looks like some storms could tap into enhanced instability and wind shear.

Even though the threat for severe storms isn’t as high as you would see in the spring, any risk for severe thunderstorms is a big deal if you’re in the path of one. It’s worth paying attention to watches and warnings this week, particularly since folks don’t normally expect severe thunderstorms now that we’ve been able to wear our coats a few times, and since there are lots of outdoor events now that schools are back in session.

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