Rain in July? Monsoonal moisture brings sweltering temperatures and brief downpours to Southern California

While it may be a most unusual accessory for summer in Southern California, an umbrella just might come in handy Thursday.

Monsoonal moisture that rolled in from Mexico this week has brought muggy and warmer-than-normal conditions to the Southland. The trend is expected to continue Thursday with another interesting surprise: scattered showers and thunderstorms through much of the day.

“We might have a slight break, and then this afternoon and evening, we’ll see more showers — particularly in the mountains and interior portions,” said Bonnie Bartling, a weather specialist with the National Weather Service in Oxnard.

The weather service noted that developing thunderstorms likely will produce heavy rain, which could result in localized flooding.

This week’s heat wave, which peaked Wednesday, has brought record-breaking temperatures to some parts of Southern California.

Camarillo reached 91 degrees Wednesday, surpassing a record of 88 degrees set last year. In Santa Barbara, the mercury hit 84 degrees, nudging past a record of 82 degrees set in 2006. Long Beach matched a daily record of 99 degrees, set in 2006. On Thursday, Long Beach residents woke up to temperatures in the mid-70s and rain, according to the weather service.

Forecasters say Angelenos should prepare for another day of high temperatures, though it likely won’t be as hot as the previous day.

The mercury is expected to hit 90 degrees in downtown Los Angeles, 82 degrees in Long Beach and 92 in Burbank. Temperatures are expected to be even higher in more inland communities, according to the weather service.

A wave of high pressure expected to move into Southern California on Friday should push some of the monsoonal influence away and provide slight cooling along the coast, Bartling said.