Timeline: New Year's Day storm brings heavy rain to Southern California

Weather Forecast for Thursday, Jan. 1

The latest forecast and air quality conditions for the greater Los Angeles area, including beaches, valleys and desert regions.

LOS ANGELES - A powerful storm system is moving through Southern California, bringing heavy rain, potential thunderstorms, and a rare soggy forecast for the Rose Parade. 

Authorities have issued evacuation warnings and activated emergency centers as the region braces for flooding and mudslides on ground already saturated by previous storms.

What we know:

National Weather Service forecasters predict total rainfall of 1-2 inches in coastal and valley areas, with 2-5 inches in the foothills and mountains. Rainfall rates could reach an inch per hour in some local areas. 

A flood watch is currently in effect for areas south of Point Conception, including much of Los Angeles and Orange counties. 

In preparation, Caltrans has closed a 3.6-mile stretch of Topanga Canyon Boulevard, and evacuation warnings are in place for residents near the Palisades, Eaton, Agua Dulce, Franklin, Bridge, Kenneth, and Canyon fire burn zones.

SoCal residents prepare for rainy New Year's Day

Southern California is welcoming the new year with another rainstorm that will continue through the weekend.

Timeline:

Thursday Morning: The Peak Impact

• 5 a.m. to 8 a.m. The most intense rainfall of the storm. High risk of isolated thunderstorms and lightning. Flash flooding is a significant concern for commuters and early parade-goers.
• 8 a.m. (Rose Parade Start): A near 100% chance of rain at the start of the floral procession in Pasadena. Expect steady, soaking rain and potential 40+ mph wind gusts in some areas.
• 9 a.m. to noon: Heavy rain persists. Rainfall rates could reach 1 inch per hour in localized downpours, specifically near the mountains and burn scar areas.

Thursday Afternoon & Evening: Tapering Off

1 p.m. – 4 p.m.: Rain begins to transition to lighter showers. The heaviest bands move south and east out of the county.

5 p.m. – 10 p.m.: Showers taper off significantly. Most areas will see a break in precipitation by late evening, though roads will remain slick and hazardous.

Friday & Saturday: The Second Wave

Friday Morning/Afternoon: A much-needed dry break for most of the region.

Friday Night – Saturday: A second, weaker storm arrives. This is expected to bring an additional 0.25 to 1 inch of rain, renewing concerns for mudslides on already saturated hillsides.

The backstory:

The Rose Parade has a long history of staying dry, with rain dampening the event less than a dozen times in its 136-year history. 

The last time rain fell on the parade was in 2006. 

This current weather event follows recent Christmas storms that have already left mountain slopes saturated and vulnerable to further damage.

Spectators brace for soggy Rose Parade

Rain or shine - the 2026 Rose Parade kicks off at 7 a.m. in Pasadena! Watch live coverage now on FOX 11.

What they're saying:

Los Angeles Mayor Karen Bass' office stated the city is prepared for outages and flooding, while the county's emergency proclamation aims to ensure "resources and assistance can be deployed quickly to support residents and communities affected by the storms."

What's next:

Emergency crews remain on standby to respond to power outages, swift water rescues, and debris flows. 

Residents in high-risk areas are urged to monitor official communications, while motorists throughout Southern California are advised to avoid driving during the peak of the storm if possible. 

Authorities will continue to monitor the wastewater system and burn scar areas as the second wave of rain arrives over the weekend.