National Weather Service United States Department of Commerce

Dangerous Heat in the Northeast and Northwest U.S.; Areas of Excessive Rainfall In the Ohio Valley and Southwest

Dangerous heat will continue to impact portions of the Northwest and Northeast U.S. through this evening. Monsoon showers and thunderstorms may result in flash flooding and debris flows from the Four Corners region into the Great Basin this week. A slow moving cold front will bring heavy thunderstorms which may produce excessive rainfall over the Ohio Valley and Mid-Atlantic through Wednesday. Read More >


Lake Effect Summary - February 12, 2015

 

 

 

 

Maximum Snowfall: Lake Erie 3.1" (Colden); Lake Ontario 13.2" (Oswego)

Duration: 12 hours +/-

Flake Scale: 1 flake*

 

The 9th lake effect snow event of the winter season was a short lived band of snow across Oswego County on February 12th. Following a clipper low that passed just to the north of Lake Ontario early Thursday morning an arctic front dropped southward across Lake Ontario. This front was dropping into a lake aggregate trough that developed over the lake within this cold airmass. Temperatures at 850 hPa were falling through the negative teens, and into the low negative 20s Celsius.

 

As temperatures aloft fell, lake effect parameters rose, with lake equilibrium levels rising to near 10k feet, and lake instability moderately rising.

 

This arctic front brought additional strong convergence along the eastern end of Lake Ontario, with the convergence enhancing the band of lake effect snow. A uniform 290 northwest flow pushed the lake effect snow inland across Oswego County through the afternoon and evening hours and dropped up to a foot of snow locally.  Snowfall rates reached 2 to 3 inches per hour with this event. As the snow band shifted on land, and wind shear increased behind the arctic front the band of snow diminished quickly by mid evening. Additionally, several inches of snow fell within a narrow band of snow across northwestern Monroe County.  

Here are some representative snow amounts from this event.

 

Off Lake Erie...
 
3.1 inches... Colden
3.0 inches... Williamsville
2.7 inches... Buffalo Arpt.
Off Lake Ontario...
 
13.2 inches... Oswego
12.3 inches... Minetto
  9.1 inches... Palermo
  8.6 inches... Fulton