How to read the map
Each dot is a city with a published calculator page, positioned by its real latitude and longitude. Colour shows which band the calculated probability falls into: low, watch, elevated or high. Size grows with forecast snowfall, so a large pale dot means snow is expected without much closure pressure, and a small dark dot means pressure is coming from something other than accumulation — usually cold, wind chill or the timing of a smaller amount.
That distinction is the reason this page exists. A snowfall map tells you where snow will fall. It does not tell you where snow will land during the morning bus window, or where a modest total will matter because it is arriving on top of an Arctic outbreak. Comparing the dot colours with the dot sizes shows you both at once.
Where the numbers come from
Opening this page makes a single batched request to Open-Meteo for every mapped city and scores each response with the same code that runs on the individual city pages. Nothing is precomputed or cached at build time, so the map reflects the forecast as it stands when you load it. The full scoring method, including every weight and threshold, is published on the methodology page.
What the map is not
It is not a snowfall forecast product, not an official warning map and not a closure announcement. It draws no coastlines, borders or roads, and it makes no claim to represent conditions between the plotted cities. School and transportation decisions belong to individual districts, boards and consortia, and the accuracy and limitations page is explicit about what the model cannot observe.