How this page works

The pipeline

Around 8 AM and 4 PM Pacific, a script pulls the authoritative GIS layers directly — no scraping, no summaries of summaries — and computes every distance on this site with the haversine formula, in statute miles, from a fixed reference point at the house in Plain. A point-in-polygon test answers the only question that really matters — is the house inside any evacuation zone? — and the answer is printed every run, even when it is no.

• ›Chelan County Sheriff's evacuation zones — the single most important source. Zone polygons carry a last-edited timestamp; any edit within 24 hours is called out, because zone edits are the true “what changed” signal.
• ›NIFC interagency fire perimeters — official mapped fire boundary, with its own capture time so staleness is visible.
• ›VIIRS satellite heat detections — 24-hour thermal hotspots. Heat is not confirmed fire; detections are labeled accordingly.
• ›NWS Spokane — fire-weather discussion, active alerts, and the wind forecast the brief reasons over.
• ›Air quality — modeled US AQI at the house from Open-Meteo/CAMS, cross-checked against AirNow and the Washington Smoke Blog.

Every run is stored as a dated snapshot, and each new run is diffed against the previous one: acreage, containment, nearest-edge distance, zone edits. The brief reports changes rather than restating the whole picture on quiet days.

Rules the brief is written under

• ›Zone boundaries come only from the Sheriff's GIS layer. News descriptions of boundaries have run more than ten days behind the actual polygon edits; news supplies narrative, never geometry.
• ›A satellite heat detection is never called a fire. A cluster seen across several days is treated as the fire's known flank or a fixed heat source; a cluster appearing overnight is flagged as unverified until a second source confirms it.
• ›When sources disagree on acreage, the NIFC situation report is treated as the reconciled number and the newer figure noted as working-current.
• ›Wind direction is the variable that matters most: westerly winds push the fire east, away from Plain; north or northeast winds down the Chiwawa or White River drainages toward Lake Wenatchee are the danger signal. Thunderstorm outflow days are flagged explicitly.
• ›If a source fails on a run, the previous values are shown with their original timestamps — stale data is never silently presented as fresh.
• ›Bad news is not softened, and alarm is not manufactured on quiet days.

The map

The map is schematic. Roads, rivers, and places are hand-plotted reference geography; the evacuation zones, fire perimeter, and heat detections drawn over them are the day's actual GIS geometry. Distance rings are straight-line miles from the house. It is built for one judgment — where is the fire relative to the house and the routes out — not for navigation. Containment lines are deliberately absent: no public GIS source carries them, and sketching defensive lines from prose would fabricate precision the page does not have.

Colophon

Designed and built in a single session with Claude Code, including the data pipeline, this page, and the twice-daily update process that kept it current for the life of the fire. It inherits the design system of the site it lives on. The section is unlisted and unindexed by request.