The open prairies of Minnesota and Wisconsin will not slow the onshore winds as much as the tree-covered shores of New York. Therefore, the frictional difference is greatest near the Lake Shore. At inland locations this effect is negligible. Obviously, the air needs to be colder than the lake waters. Water temperatures are available from buoy sounding data shown on the facsimile charts which also show the air mass is not yet very cold.
Accumulations can reach three inches per hour.
Tops of the snow showers range from 4000 to 18000 feet. When only a few factors are marginally favorable, lake effect flurries typically produce MVFR conditions. Large scale satellite pictures are of some use in analyzing lake effect snow. Low cloud streets over the lakes will show the wind direction. Also, contribution from an upstream lake can be seen.