TL;DR
- PowCall provides AI-powered 15-day snow forecasts for 26 ski resorts across 10 US states
- Forecasts are probabilistic ranges (not single numbers) based on the NOAA GEFS 31-member ensemble
- Per-resort orographic correction adjusts for mountain terrain effects on precipitation
- Every prediction is verified daily against USDA SNOTEL ground observation stations
- Accuracy scores are published publicly on every resort's forecast page
The Problem with Snow Forecasts
Every skier knows the feeling: you drive four hours to the mountain based on a forecast promising 12 inches, only to find 3 inches of windblown crud. Traditional snow forecasts are based on a single model run, don't account for terrain-specific effects, and — most importantly — never tell you how accurate they actually are.
We built PowCall to fix that.
How PowCall Is Different
Ensemble-Based Probabilistic Forecasts
Instead of relying on a single weather model, PowCall ingests the full 31-member GEFS ensemble from NOAA, running four times per day. Each member represents a plausible future atmosphere. We aggregate these into a probabilistic range — not just "8 inches" but "5-12 inches with a median of 8."
This range is the most honest way to represent forecast uncertainty, especially beyond day 3 when single-model forecasts diverge significantly.
Orographic Correction
Mountains make their own weather. A grid-point forecast at 6,000 feet doesn't capture what happens when moisture hits a 10,000-foot ridgeline. PowCall applies PRISM-calibrated orographic multipliers to each resort, adjusting precipitation based on elevation, aspect, and historical precipitation patterns from 30-year PRISM climatology.
Snow-to-Liquid Ratios
Not all precipitation falls as powder. PowCall uses the Kuchera method to estimate snow-to-liquid ratios based on the temperature profile of the atmosphere. A storm at 15 degrees produces very different snow than one at 30 degrees — and the forecasts reflect that.
Verified Accuracy
Here's what really sets PowCall apart: we publish our accuracy. Every day, we compare predictions against SNOTEL ground observations and compute error metrics across 1-day, 3-day, 5-day, and longer lead times.
You can see these scores on every resort's forecast page. If we're wrong, you'll know — and you'll know by how much.
What's Next
We're publishing regular content to help skiers make better decisions:
- Storm recaps — post-storm analysis comparing predictions vs. actual SNOTEL data
- Accuracy scorecards — weekly summaries of forecast performance across all resorts
- Resort deep dives — detailed forecasting notes for specific mountains
FAQ
What is PowCall?
PowCall is an AI-powered snow forecasting platform that provides 15-day probabilistic snowfall predictions for 26 ski resorts across the western United States. Forecasts are generated from NOAA GEFS ensemble models with per-resort terrain correction and are verified daily against SNOTEL ground observations.
How many ski resorts does PowCall cover?
PowCall currently covers 26 ski resorts across 10 US states and British Columbia, including Alta, Snowbird, Steamboat, Jackson Hole, Mammoth Mountain, Palisades Tahoe, and more. See the full list of resorts.
What does "probabilistic forecast" mean?
Instead of predicting a single number (like "8 inches"), PowCall provides a range based on running 31 different model simulations. The forecast shows a low estimate (10th percentile), most likely value (median), and high estimate (90th percentile), giving you a realistic sense of how much snow to expect.
How does PowCall verify its accuracy?
PowCall compares every prediction against USDA SNOTEL ground observation stations, which measure snow depth and water equivalent at mountain locations. Accuracy metrics including mean absolute error, bias, and range containment are computed daily and published on each resort's forecast page.
What is SNOTEL?
SNOTEL (Snow Telemetry) is a network of over 900 automated weather stations operated by the USDA Natural Resources Conservation Service across the western United States. These stations provide daily measurements of snow water equivalent, snow depth, precipitation, and temperature — the ground truth that PowCall uses to verify forecasts.
Is PowCall free?
Yes. PowCall's forecasts, accuracy data, and blog content are all freely accessible. We believe transparent, verified snow forecasting should be available to every skier.
Follow along as we build the most transparent snow forecast in skiing. View all covered resorts or read our full methodology.