Lake Effect Summary: February 6, 2015

Lake Effect Summary - February 6, 2015

Maximum Snowfall: Lake Erie 3.5" (Wales); Lake Ontario 11.0" (Lorraine)

Duration: 18 hours +/-

Flake Scale: 2 flakes**

The 8^th lake effect snow event of the winter season occurred on Friday, February 6^th. Prior to the event, on Thursday the 5^th, multi banded lake effect streamers fell south of Lake Ontario, and this activity shifted towards the southeast and then east end of the lake as northwest winds backed to westerly Thursday night. Though lake effect parameters were weakening through the overnight hours Thursday night in a warm air advection regime, a subtle plume of colder air crossed the lake in the morning hours. This plume of colder air raised the lake induced equilibrium levels from 6k to 8k feet, and also increased the instability over the lake. As a westerly flow over the long fetch of mainly open Lake Ontario waters continued through the morning hours, lake effect snow began to increase.

Westerly winds initially brought a disorganized band of snow across northern Jefferson County Friday morning. A slight veering in the wind flow brought the snow band southward, and consolidated it upon the Tug Hill region. Over the longer fetch of Lake Ontario enough instability and moisture was gathered to produce snowfall rates of 1 to 2 inches per hour for a few hours late Friday morning and into the early afternoon hours. Though the band was briefly heavy it did produce up to a foot of snow east of Lake Ontario before drier air and further lowering of inversion heights diminished the snow band in the early evening hours.

While the intense portion of the snow band was just a few hours, it did produce white-out conditions and dangerous driving conditions. These whiteout conditions on Interstate 81 produced a 35 car pile-up Friday morning in southern Jefferson County.

By the evening hours, increasing wind shear, dry air and the continued falling capping inversion height diminished the lake effect snow band.

Here are some representative snow amounts from this event.

Off Lake Erie...

3.5 inches... Wales

2.5 inches... Warsaw

Off Lake Ontario...

11.0 inches... Lorraine

10.8 inches... Highmarket

8.0 inches... Constableville

6.0 inches... Pulaski