Long duration lake-effect snow event underway (H. Michael Mogil, CCM, CBM, NWA-DS*)

While not yet issued, look for similar forecasts to be posted for other downwind areas of the entire Great Lakes region during the next several days.
This entire weather scenario is linked to a quasi-stationary surface and upper air low-pressure system across eastern Canada (Fig. 2). The system’s counter-
clockwise circulation will send winds across the Great Lakes, mostly from a west to northwest direction.
With the Great Lakes mostly ice free (Fig. 3), colder air, moving over relatively warmer water, can gain heat and moisture. This allows clouds (often low-topped) to develop in bands across the lakes (Fig. 4). As these bands make landfall, the air they are riding on experiences increased frictional drag
(friction is higher as winds blow over land than water). The result is a low-level convergence effect, adding uplift to the clouds. In areas where terrain increases inland, there is an added orography-lift effect (e.g., the Tug Hill Plateau area). In a snowfall event earlier this winter season, parts of the Tug Hill Plateau were targeted with over four feet of snow in a three-day period.
Due to the nature of “lake effect” snow events, the National Weather Service in Buffalo, NY noted early this Friday morning that, “…in lake effect snow, the weather can vary from locally heavy snow in narrow bands to clear skies just a few miles away. If you will be traveling across the region, be prepared for rapid changes in road and visibility conditions.”
© 2017 H. Michael Mogil
Originally posted 1/27/17
* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.