Data Sources

How We Get Our Data

Our goal is to give you the clearest possible picture of snow, weather, and avalanche conditions using high-quality, trusted data sources. Here's where our numbers come from.

Our Data Sources

• SNOTEL (Snow Telemetry): Automated high-elevation sensors operated by the USDA Natural Resources Conservation Service, measuring snow water equivalent, snow depth, and temperature. These stations are the gold standard used by hydrologists and avalanche professionals.
• NOAA/NWS: Official weather data and guidance from the U.S. National Weather Service.
• Open-Meteo: Weather data from global and regional weather models.
• Synoptic Data: Real-time weather observations from professional mesonet stations.
• Avalanche Centers: Danger ratings and forecasts from CAIC, UAC, and SAC, quoted without modification.
• Resort-Reported Data: Daily snow totals published by ski areas.

Why Snow Numbers Are Hard to Pin Down

Snowfall and snow depth can vary dramatically over very short distances due to terrain, wind, and storm structure. Even within a single ski area, the base, mid-mountain, and summit can receive very different amounts in the same storm.

Different instruments and methods—manual snowboards, ultrasonic depth sensors, and snow stakes—do not always agree. The timing of measurements matters too; a 24-hour total measured at 5:00 AM will differ from one measured at 3:00 PM if snow is still falling.

Forecast models and observing networks provide the best available estimates, but they cannot perfectly capture every drift, wind-loaded pocket, or micro-climate.

Why Our Numbers May Differ From Resorts

• No industry standard: There is no universal standard for how, when, or where ski resorts measure snowfall. Methods vary widely between mountains and even between seasons at the same resort.
• Snow stake placement: Resort snow stakes measure at a single location, often in wind-sheltered or wind-loaded areas that can accumulate more snow and don't accurately represent the entire mountain.
• Different locations: Our resort forecast points are mid-mountain and matched to the best corresponding weather station, which may be at a different elevation or aspect than the resort's measurement site.
• Different time windows: Resorts may reset measurements at different times than our data sources.
• Human factors: Resort numbers rely on staff reading and transmitting measurements; honest mistakes and communication errors happen.

Accuracy & Your Judgment

We use trusted government and scientific data sources and apply consistent methods to estimate snow and weather conditions. However, all data and forecasts are provided "as is" for informational purposes only and are not guaranteed to be error-free.

Actual conditions can change rapidly and may differ from our reports. Check official avalanche forecasts and use your own judgment when making decisions in the backcountry or at the resort.

Our Commitment to Transparency

TheSnowLine does not inflate or alter numbers. We take the data from our sources, apply consistent methods, and report the results as-is. As we continue to refine our approach, we will always be transparent about any changes to our methods or data sources.