Emergency Tornado Warning: Cities at Risk and Immediate Safety Steps to Protect Your Family

LOS ANGELES — A sudden tornado warning jolted millions of Southern Californians awake on Christmas Eve as a powerful atmospheric-river storm rolled ashore, prompting the National Weather Service (NWS) to urge residents of Pasadena, Altadena, Alhambra and nearby communities to “TAKE COVER NOW”. Key points • The tornado warning covered eastern Los Angeles County from 10:20 a.m. to 10:45 a.m. PT; it has since expired, but a Severe Thunderstorm Warning for 60 mph wind gusts remains in effect. • The same storm system is delivering flash-flood threats, quarter-size hail and mountain snow across California’s Central Valley and coastline. • Forecasters say a rare overlap of warm Pacific moisture, cold upper-level energy and coastal wind shear is creating a “long-duration” tornado window uncommon for the Golden State. • No injuries or structural damage have been confirmed, but officials are surveying reports of downed trees and minor roof damage in East L.A. neighborhoods. Why the tornado warning was issued Doppler radar detected tight low-level rotation inside a thunderstorm racing north at 40 mph over Alhambra and Monterey Park. Although the vortex never visibly touched down, any rotating storm over the Los Angeles Basin can quickly spawn a short-lived tornado or waterspout, meteorologists warned. Safety guidance that still applies tonight 1. Stay weather-aware: enable Wireless Emergency Alerts and check the NWS Los Angeles office (@NWSLosAngeles) for real-time updates. 2. Know your shelter: if a new tornado warning is issued, move to an interior room or basement away from windows; mobile-home residents should relocate to sturdy buildings. 3. Prepare for power outages: charge phones, stock flashlights and avoid driving under sagging power lines or flooded underpasses. 4. Holiday travel heads-up: LAX and Burbank airports report cascading delays as aircraft are rerouted around the storm’s strongest cells; allow extra time or consider rail options. What happens next The Storm Prediction Center keeps Southern California in a “marginal risk” for additional tornadoes through early Thursday as the atmospheric river slowly pivots east. A secondary impulse could regenerate rotating thunderstorms over Orange and San Diego counties overnight, so coastal residents should not let their guard down. Big picture California usually tallies fewer than 10 weak tornadoes per year, but warming ocean temperatures and increasingly volatile winter storm tracks are extending tornadic potential west of the Rockies, according to state climatologists. While today’s alert was brief, it underscores the importance of heeding every tornado warning—no matter how uncommon the threat may feel in the nation’s second-largest city. If you see funnel clouds or storm damage, share photos with #LAStorm on social media (only when safe) and email tips to nws.losangeles@noaa.gov so investigators can verify any tornado touchdowns.