How Snow Check works

Where the numbers come from

Every resort has a federal snow station nearby, part of the SNOTEL network run by the USDA. Each one measures how deep the snow is and how much water is in it, every day, the same way at every mountain. We use those stations instead of resort snow reports, so all four mountains are measured by the same ruler. The sky and wind come from the National Weather Service forecast.

How we decide

Each morning we look at two things: did real snow fall in the last two days, and will the sky be clear? Fresh snow means the station's snow got at least 4 inches deeper, or it caught a heavy, cold snowfall that packed down overnight. Clear means the forecast shows less than 30% cloud between 8 and 5.

Bluebird: fresh snow and a clear sky. The rare one.
Powder: fresh snow, cloudy sky.
Storm: snowing today.
Bluebird Groomer: no new storm, sunny sky.
Quiet: no new storm, gray sky. Usually short lines.

"Dense" snow

Sometimes heavy snow settles overnight and the depth barely changes, even though a real storm came through. The station also weighs the snow, so we can still catch it. Those days are marked "dense".

Tomorrow

Tomorrow is a forecast, so it's shown as Likely or Possible, never a percentage. After 5 PM, Snow Check opens on tomorrow.

How often is it bluebird?

We checked ten winters. Counting only days the lifts were running, Sun Valley averages about 5 bluebird days a season, Bogus Basin about 3, Brundage about 2 and Tamarack about 1. Rare, and worth knowing about.

What we can't see

A station measures snow in one spot. It can't see wind-scoured ridges, crust, or which runs were groomed. Tamarack's numbers come from a station about 10 miles away, and Sun Valley's from a station higher than the base. Always check the resort's own report before a long drive.

Rule version 3.2

If we change how we decide, the version number changes here.

Snow data: USDA Natural Resources Conservation Service, SNOTEL. Forecasts: National Weather Service. Snow Check's verdicts are our own reading of that data, not official USDA or NWS information. Bogus Basin, Tamarack, Brundage and Sun Valley are trademarks of their respective owners. Snow Check is not affiliated with, endorsed by or sponsored by them.

Snow from USDA NRCS SNOTEL; forecasts from the National Weather Service. Bogus Basin, Tamarack, Brundage and Sun Valley are trademarks of their respective owners. Snow Check is not affiliated with, endorsed by or sponsored by them.