A storm moving northwards is expected to bring warm air, increasing the risk of flooding from rapidly melting snow near the United States and Canada borders this week, according to AccuWeather meteorologists. Ice jam flooding, urban flooding, and quick rises in streams and rivers are likely in the region.
Recent mild weather has melted snow and ice in some parts of the Midwest and Northeast, while deep snow and ice still remain in areas from Wisconsin and northern Michigan to upstate New York, northern New England, and southern Ontario and Quebec. These areas are most susceptible to flooding as the same storm is causing severe weather in the southern U.S.
In the Upper Midwest and southern Canada, heavy rain is expected despite temperatures in the 30s and 40s Fahrenheit. Further east, in upstate New York and northern New England, lighter rain is forecast, but temperatures in the 40s, 50s, and possibly near 60s, along with humid air, will accelerate snowmelt.
AccuWeather Meteorologist Brandon Buckingham is closely monitoring the risk of significant flooding in northern Wisconsin, northern Michigan, and other northern U.S. towns like Sault Ste. Marie, Marquette, and Rhinelander.
Urban flooding is likely in areas where snow is still present, blocking storm drains. Major Canadian cities such as Ottawa, Montreal, Quebec City, and Toronto are at risk of urban flooding due to the thaw and storm.
The main concern is ice jam flooding in frozen streams and rivers. In areas with gradual but significant snowmelt, stream levels will rise first, followed by river levels, lasting for days.
While the flooding may not be as severe as past events, roads and bridges may be blocked by high water. Flash flooding may occur from the Ohio Valley to southern New England as the storm moves eastward.
Expect travel delays and ground stops at airports as squalls and severe thunderstorms pass through. A cold air sweep following the storm will slow the runoff, but rivers will take time to subside. Puddles, flooded areas, and dampness will linger into the weekend.
As temperatures drop, be aware that surfaces on roads in your area may become icy as they freeze. Looking for top-tier safety without interruptions from ads? Upgrade to Premium+ on the AccuWeather app to gain access to advanced, hyperlocal severe weather alerts. These AccuWeather Alerts™ are generated by our team of expert meteorologists who work around the clock to monitor and analyze potential risks of dangerous weather conditions, ensuring the safety of you and your loved ones.
