When the residents of the areas south of the Great Lakes hear or read the words “lake effect”, they know. Bands of lake effect snow can be significant, awesome and powerful; the storm bands can last for two or three days. The snow is not measured in inches, but rather feet and is usually accompanied by strong gusty winds. The winds can create “white-out” conditions, making travel treacherous and sculpting amazing drifts inland and picturesque but deadly ice-dunes along the lake shores.
Locals refer to the storms as the “snow machine”, among other less polite terms. For travelers, the bands can be nightmares as the Interstates, particularly I-90, I-79 and I-86 begin to close; schools and fire halls begin to prepare for stranded motorists, sometimes rescued with the aid of snowmobiles. Airports will be turned into huge dormitories as snow plows will be unable to keep up with clearing the runways, buses and trains, if they can move, will be running hours late. The snow machine is “kicking in”.
Each storm is somewhat unique; at times it can be a blizzard in one location, while in another a few miles away, the sun will shine. Or the lake effect storm could be more widespread sparing no one it’s ferocity.
The short explanation is the cold and dry arctic air moving across the warmer waters of the Great Lakes creates the needed moisture for the heavy snow which begins to fall inland from the shores of the lakes.
However, wind speed and wind direction, make accurate forecasts almost impossible. A wind shift of even a few degrees can send a heavy snow band hundreds of miles away. Cleveland, Erie, Buffalo, Watertown and Pittsburgh and the villages and towns in between all have their fearsome stories.
The storms can happen at any time from early October through April, the calender doesn’t have to say winter. October storms can be destructive because of the heavy snow on the trees which still have many of their colorful leaves. Downed trees and branches have caused many power outages.
Thunder snow is more common in the fall and early winter with lake effect storms. Claps of booming thunder, followed by brilliant flashes of lightning during a period of heavy snowfall is not uncommon when warm and cold clash in the region. It makes for a keen reminder about the power of Mother Nature.
There are some benefits to the complicated weather systems in the Great Lake regions during the winter months. The heavy snow cover helps to replenish the underground water tables, it provides needed protection for many plants, shrubs and trees against the sub-zero temperatures and helps in protecting the soil from erosion.
Once ice forms on the lakes, the threat of lake effect storms becomes greatly diminished, a happy event for anglers, snow plow drivers and residents. The winds can not pick up the needed moisture from the water. However, if there is no ice cover, or an early thaws melts the lake ice and a cold blast from “up north” wander south, April snows can be a dramatic winter finale.
The severity and exact location of a lake effect snow warning is determined by wind direction and speed, water temperature, ice cover on the Great Lakes and luck. In many cases, it is one of the harder forecasts to predictably make because of the variables which need to be examined hourly. Lake effect snows are powerful, awesome and some of nature’s most respected and complicated weather systems.
When the forecast calls for lake effect heavy snow squall bands, it is time to get ready and hunker down; I know first hand from living 30 miles inland from Lake Erie.