Gulf of Alaska Storm Hits Diamond Bar with Rain, Low Temps

A cold storm bearing down on San Gabriel Valley is expected to bring rain to Diamond Bar starting Monday night into Tuesday morning, according to the National Weather Service.

"There are two systems rotating around a long-wave trough," National Weather Service meteorologist James Thomas in a phone interview Monday evening. "It's the same system bringing cooler air from the Gulf of Alaska."

There remains a 70 percent chance of showers into Tuesday morning, according to the NWS forecast.

"We're going to see it steady Tuesday morning, with showers likely Tuesday afternoon and into the evening hours," Thomas said. "By (Tuesday) night, the second system will be coming in, Tuesday night into Wednesday, and rain should pick up again, maybe ending Wednesday evening."

Low temperatures in the Diamond Bar area were expected around 50 Monday and Tuesday night.

Record lows were set around the southland, with the closest reported at UCLA. An early morning reading of 47 degrees beat UCLA's previous record of 48, a record set in 1953.