Fosberg FWI — Calculated from current temp, RH, and wind speed. A simplified fire weather index. Not an official NFDRS station output — treat as directional.

Fire Danger Class — Derived from FWI thresholds: Low <20 / Moderate 20–40 / High 40–60 / Very High 60–80 / Extreme 80+. Not equivalent to officially posted NFDRS ratings at your district — cross-reference with your GACC or local dispatch.

ERC / BI — Energy Release Component and Burning Index from FEMS RAWS daily obs. These ARE station-observed NFDRS outputs.

Ignition % / Spread Index — Estimated from 1-hr fuel moisture, temp, and RH. Directional only.