A storm moving off the coast of New England during the end of the workweek will usher colder, northwesterly winds into the northeastern United States, marking the beginning of the next lake-effect snow event.
A system moving through the Northeast on Thursday will bring widespread precipitation to most of the Eastern Seaboard. While much of it will fall as rain, a mix of rain and snow is expected throughout the mid-Atlantic, changing completely over to snow in northern New England and the Great Lakes region.
Colder air will spill into the northern U.S. behind this system on a brisk northwest wind.
This chilly Canadian air moving over the unfrozen Great Lakes will combine to create plenty of lake-effect snow downwind of the lakes.
“Lake-effect snow occurs when cold air much colder than the surface waters of the Great Lakes blows over the warmer lake waters,” said AccuWeather Meteorologist Kyle Elliott.
As long as winds persist from the west or northwest, so will the lake-effect snow machine; in this case it looks to be through the end of the weekend.
“A narrow but high-intensity lake-effect snow band can develop and dump feet of snow in locations where it persists for hours, or even days, on end,” said Elliott.
Both the extensive time frame and intensity of this event will result in up to 4 feet of snow in some areas, particularly in parts of southeastern Ontario, Michigan, northwestern Pennsylvania and western New York.
“From Thursday through Monday, some residents downwind of Lake Ontario may be measuring snowfall in yards, instead of feet,” said Elliott.
Much of the affected area will accumulate upwards of a foot of snow by Sunday evening.
Even those outside the heaviest snow bands will find shoveling futile before Monday evening.
“While the heaviest snowfall is expected to occur from Friday night through Sunday morning, more scattered but still locally intense snowfall bands are expected throughout the entire period,” said Elliot.
Several major roadways will be impacted by this widespread and long-lasting snowy weather, including interstates 81, 80, 90 and 75 where they pass through areas downwind of the Great Lakes.
Anyone traveling even short distances through this region over the weekend should take precautions or avoid travel altogether.
“In just a few miles, visibility can drop from over 10 miles to just a few feet in the heaviest lake-effect snow bands,” said Elliott.
“Roadways can go from clear to totally snow covered in just a few hundred yards, and the blinding visibilities greatly heighten the risk for motor vehicle accidents and multi-car pileups.”
Elliott also explained that it is best to reduce speeds significantly and use four-wheel drive, if possible, when driving in snowy weather.
Traffic will be snarled and buildings will be slowly buried through the beginning of next week before the snow tapers off.
“A weak storm system will move through the Upper Midwest and Great Lakes from Monday night through Wednesday, bringing a temporary lull in the lake-effect snowfall,” said Elliott.
While a similar event is possible later next week, a repeat of this upcoming weekend is not expected.
“The good news is that this event should not be as intense or last as long,” said Elliott.