The Meteorology of the January 2025 Los Angeles Wildfire

Missoula Fire Sciences Laboratory

Thursday, February 19 - 1pm ET

Presenter: Clifford Mass, University of Washington

This talk will describe the synoptic and mesoscale meteorology associated with the strong Santa Ana event of January 7-12, 2025, which resulted in over $100 billion in economic loss and 30 deaths. Strong northerly and northeasterly low-level winds, reaching record levels at some locations, resulted from an unusually intense mid-tropospheric low to the south of the Los Angeles basin. With higher pressure/heights over the northeast Pacific, intense crest-level flow developed over the Southern California Transverse Range, with intense downslope flow on the southern, lee slopes. High-resolution model simulations produced a highly realistic wind evolution over the region. The strongest winds, some exceeding 80 kt, occurred on the southwestern slopes of the San Gabriel Mountains and were associated with a high-amplitude mountain wave. The predictability of the event was high, with substantial skill within three days of the start of the strong, dry winds.