Note: This post has been updated to include a remarkable video of the lake-effect band at the end.
|You don't see this every day. Even in metric, 40-60 (cm) is a pretty good storm. But this is the forecast in inches. Source: WIVB.com|
There are a number of reasons why these bands are intense. First, they form when the large-scale flow is moving over the longest axis of a lake, which means the airmass experiences the maximum heating and moistening possible. Second, the local heating over the lake surface generates land breezes that converge near the center lake axis, triggering and organizing the snowfall in an intense, localized band. The schematic below from my recently released book shows how this process works over the Great Salt Lake, but the concept is the same over Lake Erie.
|Source: Secrets of the Greatest Snow on Earth (Steenburgh 2014)|
|Source: College of DuPage|
Addendum @ 1:40 PM 18 Nov: Great video below from YouTube user Alfonzo Cutaia showing remarkable updrafts and northern edge of the band.