A low pressure system is set to set across Southern California this weekend, bringing scattered rain to coastal counties and potentially dangerous dust storms to the Coachella area, where thousands of festival-goers will gather for the first weekend of the eponymous festival.
According to the National Weather Service, light rain is possible in the L.A. County area from Friday afternoon to Saturday morning, while heavy rain is possible north of Point Conception in Santa Barbara and San Luis Obispo counties.
“Then, the second wave of this storm is going to be Saturday night, and that’s where we’ll have the potential for thunderstorms across the region,” said Rose Schoenfeld, a weather service meteorologist. “With those storms, we could see risks like high winds, (and) the potential for some locally damaging wind gusts.”
According to the weather service, rain and strong winds could also bring small hail and tornadoes or the possibility of a small tornado. Overall rainfall amounts of half an inch to 1.5 inches are expected in mountainous and foothill areas, and snow is possible in areas at elevations above 6,000 feet.
The storm system is not currently expected to impact the return of Artemis II, which is scheduled to hit San Diego at 5:07 p.m. Friday. High winds, poor visibility and rough waves could all hinder the feasibility of splashdown, but NASA has not shared concerns about crew return time or safety.
Strong winds are expected Friday in the Coachella Valley area, where an air quality warning is in effect until 3 a.m. Saturday due to harmful levels of particle pollution from airborne dust. The alert includes the cities of Indio, Palm Springs, Cathedral City, Palm Desert, La Quinta and Coachella, and the highest levels of particulate matter are expected in the northwest Coachella Valley.
“Pollution particles can travel deep into the lungs and cause serious health problems, including asthma attacks, heart and lung disease symptoms and an increased risk of lung infections,” the weather service warned Thursday. People are urged to keep windows and doors closed, run air conditioners and air purifiers, and avoid grilling or fireplaces that increase air pollution.
Although precipitation levels are generally predicted to be low in desert areas during this storm system, there is a chance of rain in the Coachella Valley on Sunday.
Festival visitors should also be aware that temperatures in Southern California are expected to be five to 10 degrees below normal on Saturday, then about six to 15 degrees below normal on Sunday. Monday will be a little warmer but still cooler than normal, according to the weather service.
The good news is that the coming rains will push back the start of this year’s high fire season, which will ease some concerns after the recent record-breaking heat wave.
“If we had been dry from that warmest March and gone straight into summer, we probably would have gotten into fire season much sooner,” Schoenfeld said.
Southern California may experience more frequent rainfall this fall and winter when a powerful El Niño system is expected to be in full effect. This so-called Super El Niño, caused by cyclical warming of water in the equatorial Pacific, could be the most powerful El Niño in a century to affect Southern California.
In the Southland, a strong El Niño increases the likelihood of a wet winter that replenishes water supplies and reduces the frequency of wildfires but can also cause flooding, debris flows, and coastal erosion. But it is impossible to predict the exact effects.
During a powerful El Niño cycle in 1997–98, intense storms caused flooding and debris flows throughout the state. However, when a Super El Niño was predicted in 2015–16, California’s annual precipitation totals were about average.
It’s unlikely the weekend rains are a direct product of the El Nino cycle, which forecasters predict will emerge sometime between May and July, Schoenfeld said. But it could certainly be a harbinger of wet, cold and windy weather, which could see more downpours in the region.
Times staff writer Alex Wigglesworth contributed to this report.
