Overview
- - The National Weather Service forecasts the heaviest rain from Wednesday night into Thursday, with 1–3 inches in coasts and valleys and 2–5 inches or more in foothills and mountains, and brief rates near 1 inch per hour in some inland areas.
- - Los Angeles County evacuation warnings begin at 11 a.m. for burn‑scar neighborhoods including the Palisades, Eaton, Canyon, Agua and Lidia, Bridge, Sunset, Franklin, and Kenneth fire areas due to debris‑flow hazards.
- - Flood watches cover much of Los Angeles and Orange counties through Thursday evening, and wind gusts of roughly 30–50 mph are possible in spots under advisories.
- - Gov. Gavin Newsom has pre‑positioned Cal OES, Cal Fire, CHP and Caltrans resources, and a planned closure of Topanga Canyon Boulevard between PCH and Grand View Drive starts at 5 p.m. Wednesday, with additional closures prepared in high‑risk corridors.
- - Pasadena is expected to be one of the most impacted valley areas, making for a wet Rose Parade, while a second atmospheric river is expected from late Jan. 1 into Jan. 4 that lowers snow levels and boosts mountain snowfall; Northern California faces morning fog and rain spreading in by afternoon.