What is lake effect snow?


But Nichols says to the west of Rochester, particularly Genesee and Wyoming Counties, snow could accumulate several inches by Friday.

A storm system is responsible for starting the process of this pattern change.

Heavy lake-effect snow is expected to develop this week as a blast of Arctic air spreads across the Great Lakes and Northeast causing localized whiteouts and more than two feet of snow in some areas.

The heavy snow will fall in relatively narrow bands, according to the Weather Service.

We average 0.4 inches of snow on Christmas. Primarily this impacts states that border the Great Lakes, but sometimes we can get lake effect snow bands to reach western MA.

Scattered snow showers will be around with no more than 30-40% daily coverage each day from late Wednesday through Friday. Now that would be more typical of a mid-winter cold weather outbreak. There are some signs it could last longer than that, covering most of December. Temperatures will remain chilly today, with highs forecast to be in the upper teens north, low 20s south. Winds will be calmer than they have been over the previous days.

We're not entirely on the sideline from snow here.

Meanwhile, cold air continues to pool over central Canada where a solid snowpack is in place. We won't rule out accumulations at this time, but the best chance of those right now look to be in central and southern in, which is a little different. When you have cold air on top of the warmer lake air you get lift.

There is of course some chance the entire period of cold passes with very little or no measurable snowfall.