Lake effect snow a possibility this weekend | SierraSun.com

Lake effect snow a possibility this weekend

Joanna Hartman
Sierra Sun

Meteorologists are predicting an infrequent Tahoe weather event starting today ” lake effect snow.

“It wouldn’t be surprising to get a few inches of snow from lake effect [in this storm],” said Rhett Milne, meteorologist with the National Weather Service in Reno.

Lake effect snow is a common weather event in places around the Great Lakes and the Great Salt Lake, but a rare phenomenon in the Tahoe area. Each year the basin may see lake effect snow just once or twice, said Milne.

“People didn’t even think it occurred here,” Milne said. “Because they said our lake is just too small.”

But lake effect snow does fall around the Tahoe Basin, and has been of interest to scientists in the last eight or so years, Milne said.

Snow from lake effect is generated from the temperature contrast between cold arctic air moving over the relatively warm Lake Tahoe waters. With air temperatures estimated in the single digits and a lake temperature of about 40 degrees, the potential for lake effect snow exists, particularly for Friday or Saturday, Milne said.

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Three components are necessary for lake effect snow in Tahoe: frigid air temperatures, fast winds, and considerable travel distance for the warm air mass to collect moisture, Milne said.

“A lot of things have to come together or we’d have [lake effect snow] every time cold came over the lake,” said Tahoe weather historian Mark McLaughlin.

And while this week’s conditions are favorable, where the weather sets up and how much snow it produces is still in question.

The snow will likely fall toward the south end of the lake, considering the direction of the cold front, Milne said.

McLaughlin said the weather forecast predicts dry air, which may actually squelch the possibility of the event.

Lake effect snow is very localized, sometimes falling within just a three-mile band.

While one small area can see more than six inches of snow, a neighboring region may only get a dusting, Milne said.

The weather service issued an advisory for lake effect snow earlier this season. A few years ago the east side of the lake into Carson City received more than six inches from such weather. And in November 2000, lake effect snow dumped more than 18 inches in Carson City and about two inches around the basin, McLaughlin said.

Lake effect snows are most common over the Great Lakes because the large bodies of water hold summer heat, rarely freeze over and provide a long fetch allowing air to gain the heat and moisture required to fuel the snow squalls, according to the National Weather Service. It is possible for any large lake to produce lake effect snow downwind if the conditions are right.

The Great Salt Lake, eastern shores of the Hudson Bay, Gulf of St. Lawrence, as well as parts of Japan, Korea and Scandinavia are also known to produce snow from such conditions.

Linda Cheng, a meteorologist with the National Weather Service Salt Lake City office, said they see lake effect snow about 10 times a year around the Great Salt Lake, usually during the beginning or the end of winter when the greatest land-to-lake temperature difference occurs.

The valleys south of the Great Salt Lake are known to get a few inches of this snow each winter and have even gotten feet of snow in years past. If the area gets a big band, Cheng said, even Alta, Snowbird and other nearby ski resorts will benefit from lake effect snow.