Plenty of heat and humidity combined with an approaching cold front will trigger severe thunderstorms Friday afternoon and evening from Chicago, Milwaukee and Detroit to Toronto, Montreal and Quebec City.
While the main story since the beginning of the week has been the oppressive heat, the focus will shift to storms as the weekend approaches. A push of cooler, drier air will begin to work its way southeastward from Canada Thursday.
As this air clashes with the hot and humid conditions across the Great Lakes and St. Lawrence Valley, thunderstorms already firing Friday morning are poised to become severe Friday afternoon and race eastward into the night.
According to Meteorologist Mark Mancuso, "Some of the storms will be moving along at 50 to 70 mph and can catch people off guard, especially boating and fishing interests on the Great Lakes and Thousand Islands region."
Northern Illinois, southern Lower Michigan, Southern Ontario and Quebec should bear the brunt of the violent weather later Friday.
Residents and people vacationing from the lower Great Lakes to the St. Lawrence should keep a watchful eye on the sky for these storms Friday afternoon and evening. Winds and waves can get rough in a matter of minutes.
According to Canada Weather Expert Brett Anderson, "This is a prime time of year for severe weather in eastern Canada. The storms on Friday have the potential to bring damaging winds, hail and even a few tornadoes."
Torrential downpours will also accompany these storms. This is not good news for locations around Toronto that experienced flooding early last week. Over 7 inches of rain has fallen in Toronto in July, over 200% of the monthly normal!
After blasting through southeastern Canada, the storms should cross into upstate New York and New England Friday evening. Severe weather could impact Buffalo, Rochester and Syracuse, N.Y., in addition to Burlington, Vt.
Saturday will also be an active day for severe weather, but the focus will shift into the Ohio Valley and the central Appalachians, approaching the I-95 corridor of the Northeast toward evening.
Meteorologists Eric Leister and Alex Sosnowski contributed to this story.
Thunderstorms and soaking rain will threaten Memorial Day ceremonies, cookouts and vacations for millions on Monday.
Millions of people in the central United States dealing with relentless severe thunderstorms and downpours will have to continue to weather the volatile pattern a while longer.
Tropical Storm Bonnie developed off the coast of Georgia on Saturday afternoon and will approach the southeastern coast of the United States with downpours, building surf and an increasing breeze during Memorial Day weekend.
Rainy weather will help to lessen the severity of the drought around Colombia and Venezuela in the coming months while drier-than-normal conditions make matters worse for the drought in Chile and northeastern Brazil.
Tropical moisture may put outdoor Memorial Day plans in jeopardy from Washington D.C., to Boston on Monday.
South East England will face rain threaten to ruin Monday's bank holiday, while the rest of the United Kingdom enjoys another mostly dry and mild day.
Yuma, AZ (1877)
Severe two-day sandstorm.
Area from Wallace to Kearney counties: a great hailstorm caused $6 million damage.
Ohio Valley (1982)
Severe thunderstorms: Tornado in Marion, IL killed 12, caused $100 million damage. Columbus, OH had a wind gust to 76 mph. Louisville, KY pelted by hail 2" in diameter.