Start with the window you care about
Every forecast on SnowBrains Weather is built from forecast days that run from 6am to 6am the next morning. Each day has a day half (6am to 6pm) and a night half (6pm to 6am). That matches how a ski day works: snow that falls overnight is the snow you ski in the morning.
The totals add those days up. Today counts the hours left today. The 5-Day Forecast adds today and the next four days. The 7-Day Total adds today and the next seven days, so it always covers a full week ahead. On the Powder Finder you can also pick 48 hours (today and tomorrow) or 72 hours (today plus the next two days).
When you plan a trip, look at the days, not just the total. Ten inches spread over a week skis very differently from ten inches that falls in one night.
Know where the numbers come from
For US resorts we use the official National Weather Service forecast for the resort’s location, the same forecast the local NWS office publishes. For Canadian resorts we use Environment Canada’s GEM model. We don’t inflate the snow numbers.
Mountains are tall, so one temperature doesn’t fit the whole hill. We adjust forecast temperatures to each resort’s mid-mountain elevation at 3.5°F per 1,000 feet. For Canadian resorts, that mid-mountain temperature also decides how much of the forecast precipitation counts as snow: all of it at 32°F or colder, fading to none at 36°F.
Expect the forecast to change
Forecasts are most reliable in the next two or three days and less certain after that. A storm a week out might arrive early, late, weaker, stronger or not at all. Treat the far end of the 7-Day Total as a heads-up, and check again as the storm gets closer. We check for new forecasts around the clock, so the numbers you see are the latest ones published.
Check the snow level, not just the snowfall
The snow level is the elevation where snow turns to rain. Above it, expect snow. Below it, expect rain, and within a few hundred feet of the line, a wet mix. If the snow level sits in the middle of the mountain, the summit can get a foot while the base gets rain.
Out West, the National Weather Service publishes a snow level, and we show it as they do. Where it doesn’t, we calculate one from NOAA’s GFS forecast, using the height where the wet-bulb temperature reaches about 33°F. Environment Canada doesn’t publish a snow level, so Canadian resort pages show the freezing level instead, the height where the air hits 32°F. Snow usually keeps falling for about 1,000 feet below the freezing level.
Watch the wind
Wind can make or break a storm day. Strong gusts can close upper lifts, strip snow off exposed ridges and pile it into gullies and lee slopes. Each resort page has an hourly wind and gust chart and a By Elevation panel for the summit, mid-mountain and base. If the summit wind is roaring, the best skiing may be in the trees.
Think about the kind of snow
Colder storms usually make lighter, drier snow, and warmer storms make heavier, wetter snow. The hourly forecast on each resort page shows the temperatures, which help you guess which you’ll get. A cold storm with modest totals can ski deeper than a warm one with bigger numbers.
Read the forecaster’s discussion
For US resorts, the resort page includes the local NWS office’s forecast discussion, under The brains behind the forecast. It is where forecasters explain their thinking: how confident they are, which models agree, and what could go wrong. If the discussion says confidence is low, take the big numbers with a grain of salt.
After the storm: reported, observed or estimated
Recent snowfall on a resort page carries a label that tells you where the number came from:
Want to know more about the stations? Read what SNOTEL stations are and how we use them.
Why totals are rounded down, not up
We round each day to the whole inch. A total then shows the smaller of two numbers: the true total rounded, or the days added up as shown. So a total never reads higher than either. If one day has 0.5″ (shown as 1″) and the next has 1.7″ (shown as 2″), the total reads 2″, because only 2.2″ is really forecast. A trace of snow shows as <1″. We would rather a number be a little low than a little too high.
Quick checklist before you go: look at the days, not just the total. Check the snow level against the resort’s base and summit. Check summit winds. Skim the forecaster’s discussion. Then read the morning’s conditions reports from skiers and riders on the Conditions page.
How good are the forecasts?
We grade ourselves in public. The Accuracy page compares saved forecasts with what nearby stations measured, resort by resort, and tells you whether our snow forecasts have been running high or low.
More guides: What SNOTEL stations are · Snow and weather glossary · Today’s snow forecast