Purpose & Methods
Why This Exists
This is a citizen science project. We built it because the people who live in the path of western wildfires and droughts deserve access to the same data and analysis that federal agencies and insurance companies use to make decisions about their lives,for free, without a paywall, without a login, without asking permission.
Our prediction model,Firewatch,is a gradient-boosted decision tree model (XGBoost) trained on 37 million observations across the western fire corridor (11 states + BC). It draws on 26 years of daily climate at 4km resolution, 1,830 SNOTEL stations, 9,800+ large-fire perimeters as prediction targets, 312,000 fires for cause classification, fuel maps, soil moisture, snow disappearance timing, and topography to identify where large fires are most likely to burn.
AUC-ROC of 0.911 means: given a cell that burned and a cell that didn’t, the model ranks the burned cell higher 91% of the time. It is a ranking metric, not a hit rate,at the 0.1% base rate, most flagged cells will not burn in a given month. The model identifies where large fires (>1,000 acres) concentrate, not individual ignitions. 2026 is the live public validation period.
15. Snow disappearance date (new to v1.0, after Westerling et al. 2006)
| Dataset | Source | Coverage |
|---|---|---|
| Daily climate (VPD, fuel moisture, temp, precip, wind, BI) | gridMET (U of Idaho) | 2000–2025, 4km, 32–49°N |
| Wind direction (east wind frequency) | gridMET, 4km daily | 2000–2025, % summer easterly |
| Snowpack (daily SWE) | NRCS SNOTEL + SNODAS | 1,830 stations, 11 states, 1981–2026 |
| Snow disappearance date | Computed from SNOTEL | 2000–2025 (novel feature) |
| Soil moisture (8-inch) | SNOTEL SMS sensors | 55 stations, summer 2000–2025 |
| Fire perimeters | NIFC WFIGS + MTBS | 6,853 perimeters, 11 states, 1992–2024 |
| Burn severity | USGS MTBS | 7,949 fires >1,000 ac, 1984–2024 |
| Fire cause | FPA-FOD | 312,000 fires, lightning vs human |
| Canadian fires | NFDB | 155,198 BC records + 1,878 polygons |
| Fuel type + canopy | LANDFIRE | FBFM40, EVT, canopy cover, 30m |
| Topography | GMTED2010 DEM | Elevation, slope, aspect, 250m |
| Climate indices | NOAA CPC | ENSO Niño 3.4, PDO, ENSO velocity |
| Reservoir storage | USBR Hydromet, USACE, CDEC | 39 reservoirs, 11 states, real-time |
| Air quality (PM2.5) | EPA AQS + PurpleAir | 700 monitors + 12,000+ sensors |
| Summer temperature | NOAA NCEI | 131 years (1895–2025), 11 states |
| Smoke feedback | EPA AQS annual PM2.5 | Prior-year smoke as predictor (novel) |
| Version | AUC | Key change |
|---|---|---|
| v0.1–0.3 | 0.67–0.72 | PNW annual grid, added topography + LANDFIRE + fire cause |
| v0.4 | 0.841 | Monthly resolution (biggest single improvement) |
| v0.5–0.6 | 0.90–0.91 | Full western corridor, lag features, interaction terms, ensemble |
| v0.7 | 0.913* | SNODAS gridded SWE. *Leaked metric — test set used during tuning. |
| v0.8 | 0.901 | Proper 3-way split, ENSO/PDO, held-out test. |
| v0.9 | 0.909 | 11-state SNOTEL, SWE anomaly, VPD×SWE interaction. |
| v1.0 | 0.911 | Snow disappearance, east wind, prior-year precip, reservoir anomaly, ENSO velocity, soil moisture, smoke feedback. 50 features. First public production release. |
Roadmap
Planned · Not yet in production
| Target | Component | Gap it closes |
|---|---|---|
| v1.1 | Live forecast + fire tracking | Daily 4km risk grids for 2026 fire season. VIIRS satellite hotspot detection (375m) for near-real-time active fire tracking. |
| v1.2 | Fuel + vegetation | LANDFIRE fuel loading maps and NDVI-derived live fuel moisture. Closes the biggest input gap in the current model. |
| v1.3 | Wind + smoke dispersion | Sub-daily HRRR winds to capture Diablo, Santa Ana, and east wind events. Atmospheric mixing height for real smoke transport modeling. Fuel-composition smoke toxicity. |
| v2.0 | Data quality + coverage | Resolve SWE measurement discontinuity at 2010 (SNOTEL station interpolation vs. SNODAS gridded). Expand Canadian coverage with ECCC station data and CFS reanalysis. |
| v2.1 | Consequence modeling | Fire behavior (rate of spread, flame length, spotting). WUI structure exposure mapping. Post-fire burn severity (dNBR) for damage assessment and model retraining. |
Station-level, no spatial prediction
25km global, monthly (GMD). Uses r not AUC-ROC,0.80 is approx.
Monte Carlo simulation
Daily, 375m, not public
4km monthly, 50 features, held-out test, snow disappearance, soil moisture, ENSO velocity, smoke feedback, public data only
Known Limitations
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Get in touchAll data from publicly available federal, state, and provincial sources. Model trained on 2000–2019, validated on held-out test years 2020–2024 never seen during training.