Tuesday, November 18, 2014

Buffalo in the Lake-Effect Crosshairs

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
Contrary to popular belief, Buffalo is not the snowiest city in the United States, it's Syracuse (96 vs. 126 inches).  However, when it comes to behemoth storms, Buffalo is king.  Why?  It sits on the eastern end of highly elongated Lake Erie and thus can be pounded by intense snowbands that form along the major lake axis.  Such snowbands are sometimes called Long-Lake Axis Parallel or LLAP bands and are responsible for some of the most intense snowstorms in the world.  Last night and today portions of the Buffalo Metro Area have been getting pounded by a persistent LLAP band, as illustrated by the 18-hour-long radar loop below.  The approximate position of the Buffalo metro area is outline by the red box.

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)
LLAP bands can be very narrow with sharp contrasts in snowfall rates and accumulations.  If you look carefully at the loop above you'll see that once the band sets up, it snows only briefly in the northern portion of the Buffalo metro area.  In contrast, the southern portion is getting absolutely pounded.  A great photo of what I think is the northern edge of the band was taken by the Buffalo News 4 staff.  On the right you are in the clear.  On the left, snowpocalypse.

Source: WIVB.com
The Weather Channel is currently reporting that up to 4 feet of snow has fallen already in the Buffalo area.  In the satellite imagery, you can see very clearly the elongated, corrugated nature of the cumulus clouds in the primary lake-effect band, with clear skies immediately to the north.

Source: College of DuPage
In northern Utah, the Great Salt Lake occasionally produces LLAP bands.  In fact, about 20% of lake-effect periods feature such bands.  However, they lack the intensity and duration of the LLAP beasties that form downstream of Lake Erie.  Of course, as good as the Lake Erie bands are, it is Lake Ontario and the Tug Hill Plateau that see the biggest and baddest LLAP bands in the world.

Addendum @ 1:40 PM 18 Nov: Great video below from YouTube user Alfonzo Cutaia showing remarkable updrafts and northern edge of the band.



  1. Hey Jim, it strikes me that the northernmost edge of the Lake Erie band has been consistently stronger than the southern edge throughout much of the event. Was this typical of your OWLES experience? I don't follow lake-effect like I used to, but it always seemed to me the precipiation was typically heaviest near the center of these bands.

    1. I've seen it north, center, and south depending on the event. I'm not sure if anyone has ever investigated the cause, but it would be an interesting issue to investigate.

  2. Would you say that we have a "buffalo lake effect" here in the Salt Lake area due to the buffalo on Antelope Island on the Great Salt Lake? Could the methane gas from the buffalo play a role?

  3. "Of course, as good as the Lake Erie bands are, it is Lake Ontario and the Tug Hill Plateau that see the biggest and baddest LLAP bands in the world."

    Isn't there more lake effect snow on the Keweenaw peninsula jutting into Lake Superior than at Tug Hill?

    And then there's Japan, where the "lake effect" is enhanced by abrupt orographic uplift onto real mountains comparable to the Wasatch.

    1. Nobody gets more lake effect than Japan. The Keweenaw is in the running with the Tug for most in the US. The most intense storms in the world, however, are produced by LLAP bands and these form preferentially downstream of elongated bodies of water like Erie and Ontario.