Map Shows States Bracing for 'Heavy' Lake Effect Snow

"Heavy" lake effect snow was expected to blanket parts of New York, Pennsylvania and Ohio on Thursday and Friday, according to the National Weather Service.

In a series of urgent messages, the NWS alerted those in areas bordering Lake Erie to be prepared for snow that could seriously impact travel conditions heading into the weekend.

"During lake effect snow, the weather can vary from bands of locally heavy snow to dry weather just a few miles away," the Cleveland NWS office warned. "Visibilities can also vary greatly. Be prepared for rapid changes in weather, visibility, and road conditions."

A map shared on the NWS website on Thursday marks areas of northern Ohio and large parts of western and central Pennsylvania and New York state that are likely to be impacted by heavy snow on Thursday night until at least Friday morning.

As of late Thursday afternoon in New York state, lake effect snow warnings were in effect for several communities bordering the Buffalo area, including Wyoming County and parts of southern Erie County until 4 a.m. Eastern Time on Friday.

Lake effect snow warnings were also in effect until Friday morning in New York's Chautauqua and Cattaraugus Counties, including Jamestown and Ocean, where up to 14 inches of snow was expected.

"Travel will be very difficult," warned the Buffalo NWS office. "Areas of blowing snow will significantly reduce visibility. The hazardous conditions will impact the evening commute today and Friday evening commutes. Gusty winds will down tree branches and cause isolated power outages."

A warning issued in Pennsylvania was in effect for Cameron, Elk, McKean, Potter and Warren Counties until 8 p.m. on Friday. Residents were urged to "consider delaying all travel" due to conditions that could result in up to 12 inches of snow acclimation and 45 mph wind gusts.

"If travel is absolutely necessary, drive with extreme caution," the State College, Pennsylvania NWS office said. "Consider taking a winter storm kit along with you, including such items as tire chains, booster cables, flashlight, shovel, blankets and extra clothing. Also take water, a first aid kit, and anything else that would help you survive in case you become stranded."

In Ohio, the warning was limited to Crawford County, including Meadville and Titusville. Lake effect snow was expected to produce up to 12 inches of snow until 1 a.m. on Saturday.

NWS Weather Prediction Center meteorologist David Roth told Newsweek that the heavy snowfall would likely be followed by a "milder trend" in northeastern weather that could begin as soon as Sunday.

Lake effect snow is a phenomenon that causes heavy snow in the Great Lakes region intermittently throughout the late fall and winter. According to NWS, clouds capable of producing up to three inches of snow per minute are formed when cold air, often coming from Canada, collides with the comparably warm waters of the Great Lakes.