Estimating dates of the snow accumulation season

It is often necessary to estimate the average snow accumulation season, defined as extending from the first persistent snowfall to the time of peak water-equivalent, as a first step in estimating average winter precipitation. The snow accumulation season is shown to be delimited by dates when air temperatures reach 0 degrees C, as computed from mean monthly temperatures. For locations lacking climatological records, estimates can be derived from multiple regressions relating 0 degrees C dates at surrounding stations to elevation, latitude, and longitude. Regression equations are presented for all states in the snow belt, and a general equation indicates that dates of the snow accumulation season vary at the average rate of 2.5 days per 100 meters of altitude, 5.5 days per degree of latitude, and 1 day per degree of longitude, earlier northward, eastward, and upward in the fall, and the reverse in the spring.