LAKE EFFECT STORM "COPERNICUS"

December 1-2, 2002

Maximum Snowfall: Lk. Erie: 26" (Ashville); Lk. Ontario: 9" (Highmarket).

Duration: 24 Hours +/-

Prime Feature: Affected Buffalo Bills game and Metro areas.

Lake Flake Scale: **** 4 Flakes

The winter really started to wind up with our third event of the season. The storm occurred on the 1-2 of December, a time frame that has seen its fair share of lake effect storms in the past. The most intriguing aspect of this storm is that it received national media attention as fans tuned in to the end of the Buffalo Bills-Miami Dolphins football game on that Sunday afternoon.

The event began to unfold late Saturday night under a cold northwest flow that developed after a cold front had crossed the region. In fact, a narrow band of snow off Lake Huron actually produced about 5 inches of snow over parts of Genesee county on Saturday night.  Farther south, over the higher elevations of western Chautauqua county, up to 18 inches of snow occurred. By Sunday morning the Lake Erie band began to gather "steam" as winds started to back to a southwest direction. The Lake Erie band began to gather "steam" as winds started to back to a southwest direction by Sunday morning. The wind shift was in advance of a fast moving Low pressure system that was forecast to cross just north of Buffalo from the Upper Great Lakes on Sunday. Computer models were having a very difficult time with the exact location and path of the low. As a result, as late as Saturday, the models did not predict the low to move as far north as it eventually did on Sunday night. By Sunday morning however, forecasters had a good idea of the life cycle of this storm.

The forecast called for the band to move across the Orchard Park area about the time the game would be ending, 4PM. This is exactly what happened. Fortunately, many fans had enough time to get back home before the snowfall became too deep to negotiate.

By Sunday evening the band had intensified and moved right across the city of Buffalo and into the northern suburbs. Snowfall rates of 1 to 2 inches an hour were also accompanied by lightning and thunder at times.  In addition, the winds were strong enough to extend the snow band as far east as Rochester where anywhere from 4 to 8 inches of snow piled up, heaviest on the west side of the city. This is important, because at times Rochester can get its heaviest snows off Lake Erie instead of Lake Ontario. The band swung south of the city after midnight and stalled just to the south of Buffalo, over places like Orchard Park and Elma where over 20 inches of snow eventually accumulated.

On Monday, the band itself weakened and continued to drift south. However, another larger scale weather disturbance brought a round of general snowfall across the western part of the area including the city of Buffalo, where another 6 inches of snow occurred.

Farther east, off Lake Ontario, the snowband never really got going as strong. This was likely due to the track of the main surface low across the Great Lakes. The low actually moved a bit south of Lake Ontario and did not provide the favorable wind direction for an extended period of lake effect snow.

Because the event produced double digit snowfall, and affected a large population center, it will receive a four star (****) flake rating

Final snowfall totals ran 20 to 22 inches off Lake Erie with a maximum over the higher elevations of Chautauqua county where a spotter reported storm totals from Saturday night through Sunday of 26 inches.  8 to 12 inches occurred off Lake Ontario. One of the lake effect scenarios forecasters often worry about is a massive lake effect storm hitting during an outdoor event such as an NFL game. Fortunately, this event waited until the end of the game and was not accompanied by extremely cold temperatures or strong winds. It does however, point out that residents should be prepared for such conditions when they will be outside for extended periods of time.

Off Lake Erie

Off Lake Ontario