Pasadena Braces for Heavy Rain, Flood Risk as Storm Approaches

A fast-moving Pacific storm is expected to bring heavy rain, thunderstorms and potential flooding to Pasadena and the greater Los Angeles region beginning late Monday night, prompting local officials to activate flood mitigation measures in vulnerable areas.

“We are currently expecting 1-2 inches of rain, with a small possibility of greater amounts,” city chief communications officer Lisa Derderian told Pasadena Now on Sunday.

“Residents should also expect windy conditions Monday night through Tuesday night.  We are monitoring the burn scar areas and working with regional partners in preparation.”

The National Weather Service on Sunday forecasted the heaviest precipitation likely between Monday night and Tuesday evening. The system may also produce hail, gusty winds, and isolated waterspouts or weak tornadoes.

“A low-pressure system moving southward along the West Coast will bring stronger onshore winds Monday into Tuesday night, along with showers from the coast to the mountains,” the NWS said in a statement.

To reduce the risk of mud and debris flows, Pasadena is installing K-rails in at-risk zones and is urging residents to prepare for possible flooding.

“Don’t wait until the last minute to be prepared,” Derderian urged. “Plan now to ensure you have proper prep-cautions in place especially if you live in or near the burn scar areas. Stay tuned for more information regarding timing and rain amounts.”

She said residents should have a “go bag” at the ready and suggested they sign up for emergency alerts (the Pasadena Local Emergency Alert System, or PLEAS, system).

Derderian also said that sand and sandbags are available at Pasadena Fire Station 37, at 3430 E. Foothill Blvd., and Station 38, at 1150 Linda Vista Ave., and could be offered at other stations if needed. There is a 10 sandbags per resident limit. Fire personnel will be on hand to assist with loading sand into bags if not responding to a call.

In Pasadena, officials are particularly concerned about the burn scar left by the Eaton Fire, which began in Altadena in January.

The storm is expected to bring gusty south-to-southwest winds to the Los Angeles County mountains and Antelope Valley foothills. Daytime temperatures will drop sharply Tuesday, with highs in the low 60s across Los Angeles and Orange counties. Conditions are forecast to improve by Wednesday night, with gradual warming expected into the weekend.

The National Weather Service noted that inland areas will continue to warm through the weekend, while coastal regions may see the return of marine layer clouds and fog.