Wildfire — San Diego County Valleys, California

2017-12-07 to 2017-12-09 · San Diego County Valleys, California

Event narrative

The Lilac Fire began on the 7th near Interstate 15, and spread rapidly through the San Luis Rey River Basin near Bonsall. The fire consumed 4,100 acres, destroyed 157 structures and damaged 64. Over 100,000 residents were forced to or advised to evacuate and 20,000 people lost power. The fire was fanned by sub 10% relative humidity values and wind gusts over 50 mph. The fire was 100% contained on December 16th, but the majority of damage occurred in the first 48 hours. Damage value is an estimate.

Wider weather episode

A strong upper level trough swept through the Rockies on the 3rd of December, ushering a strong surface high into the Great Basin. The high peaked at 1048 mb on the 7th and brought a prolonged period of strong Santa Ana Winds and very dry weather to Southern California. The most intense winds occurred on the 7th. The Lilac Fire began on the 7th near Interstate 15, and spread rapidly through the San Luis Rey River Basin near Bonsall. Damage to trees and power lines also occurred, along with some road closures.

Source: NOAA Storm Events Database, event_id 731496. Narrative written by the NWS forecast office that issued the report.