Snowfall Progress

Location

Cumulative Snow Accumulation (Estimated)

Methodology: Total snowfall in an episode is an estimate of recent (24hr) actual snowfall plus predicted (48hr) new snow. Despite what you might expect, "actual" (past) snowfall has significant uncertainty. The U.S. National Weather Service API doesn't directly report recent snowfall totals, but does report "liquid equivalent precipitation". That's a number computed by collecting precipitation in tubes and melting any frozen part. That's related to snowfall but not in a straightforward way: 1) we have to distinguish snow, sleet, ice pellets, etc., 2) at colder temperatures, snow tends to be less dense, and 3) at higher wind speeds, more snow bypasses the tube. This page implements corrections for those issues, but please note that it is not based on actual measured ground accumulation. The predicted future snowfall also has uncertainty, but likely of a kind you already expect.