US Winter Forecast: New Lake Effect Snow to Hit Great Lakes Region This Week [NWS]

A lake effect snow is set to hit the Great Lakes region of the United States this week, according to the latest forecast of the National Weather Service (NWS). Heavy snow is expected to continue downwind of the Great Lakes. The same phenomenon was responsible for dumping more than 40 inches of snow to the Northeast US in late November.

US Winter Forecast

In its US winter forecast on Wednesday, the NWS' Weather Prediction Center (WPC) at 2:16 a.m. EST (local time) highlighted not only the looming lake effect snow over the Great Lakes. It also issued a weather alert for wintry conditions in different parts of the US, including in the Southern Rockies/High Plains where moderate to heavy snow are expected through early Friday morning, December 15.

The lake effect event occurs as a powerful system causes winter weather conditions in southern and eastern Alaska on Wednesday, December 13. The latest US weather forecast also comes a week after the weather service issued winter weather advisories for the Pacific Northwest and an alert for a cold front, which moved from central to eastern states of the country.

What is Lake Effect Snow?

Lake effect snow, sometimes spelled as "lake-effect snow," is common across the Great Lakes region of the US during the late fall season and winter season, according to the NWS. This phenomenon occurs when cold air mass, often originating from Canada moves across the open waters of the Great Lakes.

In particular, the cold air passes over the unfrozen, warm waters of the lakes. Warmth and moisture are then transferred into the lowest part of the atmosphere. When the air rises, clouds form and grow, producing at least 2 inches to 3 inches of snow per hour, the US weather agency said.

The National Oceanic and Atmospheric Administration (NOAA) further explains that the lake effect phenomenon happens when northern or westerly winds blow over the lakes' surface, where it absorbs up heat and water vapor that produce warm columns of air called thermals.

These columns cool down and condense into cumulus clouds, which can dump heavy lake effect snow along the downwind shores of the lakes, when there is significant temperature contrast, according to the NOAA.

2022 Lake Effect Snowstorm

In November 2022, a dangerous lake effect snowstorm dropped more than 6 feet of snow in some parts of New York, where at least three people died. Residents of northern and western New York woke up to the devastating impact of the winter storm, with the Buffalo metro area receiving over 5 feet of snow.

A succeeding winter storm in late December 2022 saw a relatively high number of fatalities in western New York, where a blizzard blanketed the state during the Christmas holidays, killing nearly 40 people, according to initial reports. The deadly winter storm also caused widespread disruption during the holidays.