Lake Effect Storm Alewife - November 26-27, 2010
Maximum Snowfall: Lake Erie 10"
(Attica); Lake Ontario 13" (Beaver Falls)
Duration: 24 hours +/-
Prime Feature: Marginal early
season event, good eastward extent.
After a very quiet autumn, the 2010-2011 lake effect season finally got underway with a relatively modest but notable event on the day
after Thanksgiving. Just enough cold air filtered in behind a departing storm system (850 mb temps of -8 to -10c) on a westerly flow to set
off some light snow showers off Lake Erie around midday on Friday 26th. The activity lifted northward slightly later in the afternoon and
became a broad 20-25 mile wide area of light snow for several hours. Drier air became entrained into the feature and limited any further
development until mid evening when an approaching trough moistened up the lower layers and re-energized the plume and backed the winds
enough to lift in up across central Erie county later in the evening. The activity became intense as it merged with the trough with 1-2
inch/hour rates from about 11 pm to 3 am as it settled southward. Some thunder and lightning was reported during this period. It weakened
toward daybreak as it dropped across the Southern Tier and dissipated by mid morning.
East of Lake Ontario, a similar scenario ensued, albeit a few hours later. But, the Friday evening activity was more intense as the boundary
layer was a bit more moist than it was off Erie. There were two rather intense bands from about 8 pm to midnight, and they then merged during
the early morning hours of 27th before settling south and dissipating by early morning Saturday. There was another burst as a strong trough
dropped across the region during the late morning and midday Saturday with 1-3 inches in just an hour or so as it moved south, but strong
subsidence followed and little redevelopment occurred Saturday night.
Snowfall totals were relatively modest, although there was a good swath of 6 to 10 inches across parts of central and southern Erie counties
from about Elma and Orchard Park, east and southeast across the Boston hills into western Wyoming County. 3 to 5 inches fell northward up to
Alden and Akron and into southern Genesee county. There was a sharp cutoff on the northern edge as usual, with 3-4 inches in Lancaster, 2
inches at the Airport and virtually nothing in Williamsville or Delaware Park. Amounts also tapered down to the south, with 4 inches from
Springville to Perrysburg but only an inch at Ellicottville. There was a good eastward extent to the activity due to very strong 850 mb
winds, with 3 inches at Avon and an inch of Lake Erie snow even extending into parts of Ontario and Wayne counties.
Off Lake Ontario, the heaviest snow fell in a band across southern and eastern Jefferson and the northern half of Lewis counties. Amounts
were less near the lakeshore with more graupel and pellets, with 3 inches in Watertown ranging up to 6-7 inches at Carthage but up to a foot
in northwest Lewis county on the Tug Hill. Lesser amounts fell southward across the southern Tug Hill and Oswego county with only 1-3
Much of the snow fell as snow "pellets" due to the marginal temperatures.
This was a modest event with limited impact. It did include a bit of lightning. It therefore earns two ** stars.
Here are some representative reports.
Off of Lake Erie...
|Blasdell, West Seneca
||Trace to 2 inches
Off of Lake Ontario...
||3 to 5 inches