Snow Maps
The following snowfall forecast maps are based on the European Centre for Medium-Range Weather Forecasts (ECMWF) model and are updated four times per day. Snowfall amounts are calculated using a snow-to-liquid ratio (aka “fluff factor”) of 10:1 meaning 10 inches of snow for every 1 inch of liquid precipitation. In reality, the ratio varies with temperature. Colder air produces lighter, fluffier snow where ratios can reach 20:1 or higher. Temperatures near or above freezing result in wetter snow with lower ratios such as 5:1. As a result, actual snowfall may be higher than shown in very cold conditions and lower than shown when temperatures are marginal for snow. When viewing snowfall forecasts several days out, focus more on the potential for a snow event based on day to day consistency of the forecast and trends in forecast amounts. As the event nears, you can gradually shift attention to snowfall amounts.