Karl Foord, Extension Educator - Horticulture
Snowflakes are composed of 6 sided snow crystals. When the temperature in the troposphere (the lowest layer of earth's atmosphere) is significantly below freezing, the snowflakes created under these conditions are small and termed dry snow. When the temperature in the troposphere is close to freezing, the snowflakes melt enough to create a water film enabling flakes to stick together.
Other sources have reported the Guinness Book of World Records to have the largest reported snowflake ever at 15 in. wide by 8 in. thick. This observation was made by a rancher in Fort Keogh, Montana on January 28, 1887. I tried to confirm this on the Guinness website but a search under snowflake returned zero results. However in the letters to the editor section of the periodical Nature from 1887 (vol. 35,p. 271) snowflakes up to 4 inches across were observed on January 7, 1887. This was done by catching the flakes on circular glass plates chilled for the purpose. These large flakes only fell over a 3 minute period.
Another way to measure these flakes with some form of accuracy is to create a grid on a dark piece of paper. If the grid is made up of 1 cm squares then a reference exists to reference the size when the flake falls on the paper. One would need more than an 8.5 x 11 sheet of paper to catch a Guinness record. I attempted to photograph this event. Photo 1 shows the view without snow. Photo 2 shows the view with snow, and photo 3 shows the snow captured at a shutter speed of 1/30 of a second so the length of the streaks shows you how far the snow moved in that time period. Photo 2 was taken at 1/640 of a second.
Granted this is not exactly horticulture, but I thought this might be a good if not whimsical way to usher out this year's snow as we anxiously await spring.