About PowSwirl
PowSwirl is a free snow forecasting platform built to give skiers and riders the same tools that paid services charge $50–100/year for. Everything is free, transparent, and powered by public data.
Why PowSwirl Exists
Weather data is publicly funded. The models (GFS, HRRR, ECMWF), the observation networks (SNOTEL, METAR, RAWS), and the road sensors (CDOT) are all paid for by taxpayers or operated by government agencies. Yet accessing this data in a useful format for skiing typically costs $50–100/year.
PowSwirl aggregates these public sources into a single, fast, ski-focused interface — completely free. We don't just pass through raw data; we compute temperature-based snow-to-liquid ratios, blend multiple forecast models with transparent weights, and present it in a way that answers the only question that matters: where's the powder?
Core Principles
Free Forever
Every feature on PowSwirl is free. No subscriptions, no paywalls, no ads. We believe weather data funded by taxpayers should be freely accessible.
Transparent Methodology
Our forecast blend algorithm is fully open. We show you exactly which models we use, how they're weighted, and why — no black boxes.
Open Data
All our data comes from public government sources: NOAA, NWS, SNOTEL, CDOT. We aggregate and present it — we don't gatekeep it.
Western US Coverage
130+ ski resorts across 10 states, from Colorado's Front Range to California's Sierra Nevada, Washington's Cascades, and everywhere in between.
Data Sources
All free, all public. No API keys required for any upstream source.
Primary forecast engine providing 7- and 14-day multi-model predictions at 600 calls/min
Official National Weather Service zone forecasts and active winter storm watches/warnings
800+ automated stations measuring snow depth, SWE, temperature, and precipitation across the western US
1km resolution snow depth tiles covering the continental US, updated daily
Composite radar imagery with 2-hour history and 30-minute forecast animation
I-70 corridor and mountain pass road temperature, visibility, and traction law status
What We've Built
PowSwirl has been built in phases, each adding depth and coverage.
Colorado resort pages with 7/14-day forecasts, multi-model comparison, interactive MapLibre map with snow depth + radar
Transparent multi-model blending with temperature-based SLR, SNOTEL bias correction, powder rankings, favorites, and alerts
2,700+ weather station explorer, I-70 road conditions, resort comparison, and Weather API endpoints
130+ resorts across CO, UT, CA, MT, WY, ID, WA, OR, NM, and NV with state filtering and regional rankings
About and methodology pages, SEO metadata, sitemap, OpenGraph images, and PWA support
Key Features
Want the Technical Details?
Read our full methodology page to learn how PowSwirl Blend works, including model weights, SLR estimation, bias correction, and why we chose precipitation over snowfall variables.
Read the MethodologyReady to Find Powder?
Start tracking 130+ ski resorts with the most transparent snow forecasting platform available.