November 2018 Woolsey Fire — Los Angeles/Ventura, CA

96,949 acres • 1,643 structures destroyed • Santa Ana wind event • Mode 1 Damage Assessment

⚠ Uncalibrated — DR multipliers pre-DINS calibration. Loss estimates are indicative only.

Estimated Loss

$8.8B

Ground-up structural loss (Mode 1)

$190.1B total RCV in bbox

Color Mode

Zone Legend

Z1Core (interior)

Z2Transition (0–150m)

Z3Ember cast (downwind)

Z4Fringe (500m–1.5km)

Zone Summary

Zone	Structs	Est. Loss
Z1	18,702	$6,847M
Z2	5,349	$702M
Z3	125	$6M
Z4	30,678	$413M

Layers

Fire perimeter LANDFIRE fuel model

Perimeter: NIFC GeoMAC (final, 100,874 ac)
Structures: Hummingbird SI (CA)
Zones: geometric distance from perimeter
DR: pre-calibration fixed values

Mode 1 — Damage Assessment Methodology

Zone Architecture

Structures are assigned to zones Z1–Z5 based on their geometric relationship to the final fire perimeter:

Z1 (Core): Interior of burned perimeter. DR 0.70–0.90. Primary loss zone.
Z2 (Transition): 0–150m outside perimeter. DR 0.20–0.40. Residual/spotting.
Z3 (Ember cast): 150–500m, downwind sector ±60°. DR 0.05–0.15.
Z4 (Fringe): 500m–1.5km. DR 0.01–0.05. High-value structures only.

BDI (Lee Building Damage Index)

BDI = H × V × E, where H is the zone hazard weight, V is vulnerability (roof material, occupancy type, slope), and E is normalized RCV exposure. Loss = DR(BDI) × RCV.

Calibration Status

DR multipliers are pre-calibration defaults. DINS (CAL FIRE structure damage surveys) calibration against Camp Fire and Tubbs Fire will adjust zone-specific DR values. Estimates shown are indicative only.

Perimeter Source

Final containment perimeter from NIFC GeoMAC (100,874 acres). Sequential daily perimeters (19 observations Nov 8–21) available for Event Replay mode (Phase 3).