Lightning lit up the sky in Mount Pleasant, S.C., and will soon do the same across the Midwest and Northeast. Photo submitted by AccuWeather.com Facebook fan Sarah S.

“Damaging winds are the greatest threats from the strongest thunderstorms…”

As heat and humidity surge into the Midwest and Northeast, the stage will become set for an eruption of potentially damaging thunderstorms Sunday into Monday.

The door will open for oppressive heat and humidity to invade more of the Midwest on Sunday as an area of high pressure shifts farther off the East Coast.

While the Northeast will see a slight increase in humidity levels on Sunday, Monday is when residents will definitely notice the steamy air’s arrival.

Once the heat and humidity is in place, the atmosphere will essentially become a matchstick waiting for something to strike it and ignite severe weather. That spark will come as a cold front drops down from Canada.

Violent thunderstorms along the front will first erupt from eastern North Dakota to central Ontario Sunday afternoon. Northern Minnesota, including International Falls, lies within this zone.

The severe weather will shift into the St. Lawrence Valley and the eastern and central Great Lakes Sunday night, then the lower Great Lakes and Northeast on Monday.

Chicago and Detroit will be at risk for the powerful thunderstorms at anytime on Monday. The danger will not unfold until Monday afternoon along the Northeast’s Interstate 95 corridor from Portland to Boston to New York City to Baltimore.

Before the Sunday-Monday severe weather event unfolds, a preceding cold front will continue to threaten the corridor from North Dakota to northern Ontario with violent thunderstorms into tonight.

Damaging winds are the greatest threats from the strongest thunderstorms Sunday into Monday. Frequent lightning, downpours and hail are other dangers. A tornado or two cannot be ruled out.

While the passage of the violent thunderstorms will reduce humidity levels across the upper Great Lakes and Northeast by Tuesday, the relief will not last long.

High heat and humidity will once again expand its grip to the East Coast later next week.