Southern California weather: Unseasonable 80 degrees in December

Southern California isn’t going to see much wintry weather this first week of December, with forecasts showing unseasonably high temperatures.

A combination of a high pressure system and weak offshore winds will bring warm weather to the Southland early this week, said David Sweet, a National Weather Service meteorologist in Oxnard.

“Those offshore winds, plus the area of high pressure, are going to push temperatures 10 to 15 degrees above normal,” Sweet said.

Tuesday will be the warmest day, with highs reaching into the high 70s and low 80s. Downtown Los Angeles is forecast to reach 81 degrees, Los Angeles International Airport is expected to peak at 79, Woodland Hills at 83 and Long Beach at 80.

In the San Bernardino Mountains, the warm spell will make it harder for some recently opened ski resorts to expand their open slopes. But Justin Kanton, a spokesperson for Big Bear Mountain Resort, said the weather shift is not yet interrupting the ski area’s plans, though teams continue to monitor the weather — especially nighttime temperatures, which have to stay low enough for the resort’s snowmakers to blow fresh snow.

“Seasons like this, starts like this, are not out of the ordinary for us,” Kanton said. He called last year exceptional for both its start and the epic snowfall, which extended skiing well into the summer.

Big Bear Lake will see highs around 60 on Tuesday and Wednesday, but Kanton said things should be cooling down by Thursday. Snow Summit remains open daily with limited lifts and runs, while Bear Mountain is only open for an extended weekend, so Kanton didn’t expect the midweek warmth to create significant issues.

“As of now, what we have open will remain open, and then we’ll look to expand” when conditions make it possible, Kanton said.

In the Central Valley, the warming trend is forecast through Wednesday, when afternoon temperatures could set records, according to the National Weather Service.

Fresno could reach 71, which would beat its prior daily record by one degrees, while Hanford’s forecast high of 72 would be two degrees higher than its daily record. The Central Valley will see cooling begin Thursday.

By Wednesday, Los Angeles will begin to feel some slight cooling through the rest of the week as a new system moves down the coast.

That system will bring some rainfall to the Bay Area as early as Tuesday night, with light rains expected on and off through Friday. Meteorologists expected the rain to be mostly beneficial, with little chance for flooding.

The precipitation won’t move much farther south, forecasters said, though temperatures will drop. About a week ago, the atmospheric river storms fueling the wet weather had been projected to hit California, but they shifted north, taking aim more squarely at the Pacific Northwest, UCLA climate scientist Daniel Swain said in a social media post.