(WMBD) — Midwesterners are no strangers to snow, and as winter hits the Great Lakes region, they can expect to see two distinct snow patterns show up.
These snow patterns can create dangerous conditions for driving and any recreational activity outdoors. Even the NFL moved the Buffalo Bills’ home game Sunday to Detroit because of the lake-effect snowstorm forecast to hit the Western New York region.
But what does lake-effect snow entail, and how does that differ from lake-enhanced snow? Chief Meteorologist Chris Yates explains the difference below.
Lake-effect snow develops when a cold air mass moves over a relatively warm body of water, especially if the winds from the ground up are blowing parallel to the orientation of the lake. If the winds are blowing perpendicular to the orientation of the lake, there will still be lake effect snow, but the cold air will spend less time over the warm body of water and therefore the snow will not be as heavy.
From there it is basic meteorology – warm air rises, rising air expands, cools, and condenses into clouds and precipitation develops. For the Great Lakes, the biggest lake effect snow events take place in Fall and early winter, when the lake water temperatures are their warmest.
In the case of this week’s lake effect snow event, surface air temperatures are in the 20s and lower 30s, while water temperatures are currently in the upper 40s and lower 50s. That means there will be a lot of warmth and moisture being transferred into the atmosphere, leading to the formation of these narrow, heavy bands of snow.
What makes this event so prolific is that the temperatures aloft are sitting between 14° and -4°, which is a temperature range that is conducive for snowflake production. This means that with good rising air originating from the surface of a warm/moist lake, the narrow bands of snow will produce snowfall rates of 3-4 inches an hour for several hours on end.
As lake temperatures drop and the lakes freeze over during the winter, lake-effect snow events become less of a problem.
Lake-enhanced snow develops in the exact same way as lake-effect snow. The only difference is that lake-enhanced snow occurs during a broader snow event where the cold air moves over the relatively warm water, resulting in heavier rates of snow near the shore of the lake. While lake-enhanced snow will happen during a broader storm system, you can end up with a single 5 to 10 mile-wide band of lake-effect snow on what would otherwise be a cold and sunny day everywhere else away from the lake.