A massive fog bank that has been blanketing much of California’s Central Valley with low-lying clouds since Thanksgiving time has prompted fears online of a mysterious and harmful “radiation fog,” but scientists say this is a misunderstanding of basic scientific terms and common weather patterns in the region.

“There’s something in the fog that I can’t explain,” a California man said in a recent video as he wiped soot from his truck bumper, in a post by Wall Street Apes, a popular X account.

There is indeed a “radiation fog” over the region, but that term refers to the general radiation of energy, not nuclear radiation. During radiation fog events, or “tule fog” as it’s known in California, named for a native marsh plant, fog forms when the moist ground cools rapidly at night, causing water vapor in the air to condense into thick fog.

A rainy autumn and winter in California, as well as a late November high-pressure system over the state, has further exacerbated this effect, helping create a fog bank that often stretched 400 miles up the center of the state.

Residents described the fog, which may actually be getting less common in the region compared to historical trends, as cold and eerie.

open image in gallery

“It’s like going into a dream stage where you can’t see anything around you,” David Mas Masumoto, a peach farmer in the San Joaquin Valley, told The New York Times. “You feel like you’re in this twilight zone.”

Masumoto added that he can’t remember another time with such thick fog in the last 50 years.

As for the particles that some residents were seeing in the fog, there’s a standard explanation for those too.

“Fog is highly susceptible to pollutants,” Peter Weiss-Penzias, a fog researcher at UC Santa Cruz, told The Los Angeles Times.

open image in gallery

The Central Valley, home to the state’s key north-south highway and miles of agricultural land, is known for its poor air quality.

“It could be a whole alphabet soup of different things,” Weiss-Penzias added.

The fog, which continued through late this week, is expected to thin out as heavy rains disrupt weather patterns in the state.

One lucky Southern Californian has won over $2.3 million after numbers were drawn for the Powerball jackpot on Saturday night.

Although no winner hit all six numbers for the $1.5 billion jackpot, one ticket matched five numbers and will take home $2,323,527.

The winning numbers were 4, 5, 28, 52, 69 and a Powerball of 20. The Power Play multiplier was 3x.

The SoCal ticket that hit five numbers was sold at Wright’s Market at 2691 Ventura Blvd. in Oxnard.

The Powerball jackpot will rise to an estimated $1.6 billion for the next drawing on Monday, Dec. 22 – the game’s fourth-largest prize ever and the fifth-largest among all U.S. lottery jackpots.

If a player wins Monday’s jackpot, they will have the choice between an annuitized prize estimated at $1.60 billion or a lump sum payment estimated at $735.3 million. Both prize options are before taxes.

If the winner selects the annuity option, they will receive one immediate payment followed by 29 annual payments that increase by 5 percent each year.

The new prize marks only the second time in Powerball history that the game has produced back-to-back jackpots exceeding $1 billion. The only other time was in 2023, when a $1.08 billion jackpot was won on July 19, followed by a $1.765 billion jackpot on Oct. 11. Both jackpots were won in California.

The odds of winning the jackpot are 1 in 292.2 million and the overall odds of winning any prize are 1 in 24.9. 

Top 10 largest U.S. lottery jackpots across Powerball and Mega Millions:

• $2.04 Billion – Powerball – Nov. 7, 2022 – CA
• $1.787 Billion – Powerball – Sept. 6, 2025 – MO, TX
• $1.765 Billion – Powerball – Oct. 11, 2023 – CA
• $1.602 Billion – Mega Millions – Aug. 8, 2023 – FL
• $1.60 Billion est. – Powerball – Dec. 22, 2025
• $1.586 Billion – Powerball – Jan. 13, 2016 – CA, FL, TN
• $1.537 Billion – Mega Millions – Oct. 23, 2018 – SC
• $1.348 Billion – Mega Millions – Jan. 13, 2023 – ME
• $1.337 Billion – Mega Millions – July 29, 2022 – IL
• $1.326 Billion – Powerball – April 6, 2024 – OR

Lottery officials noted that so far, the 45 consecutive Powerball drawings without a jackpot winner have raised over $100 million for public schools in California.

“Every California Lottery game sold contributes to the Lottery’s mission of raising extra money for California’s public schools,” lottery officials said. “These funds support a variety of programs across the state.”

Powerball tickets are $2 per play and drawings take place every Monday, Wednesday and Saturday night at 7:59 p.m.

The Pineapple Express storm bearing down on Southern California could bring heavy rain and strong winds throughout Christmas week, potentially triggering mudslides, downing trees and flooding not only freeways but also homes and businesses.

If the forecasts are right, this could be one of the stormiest Christmases in recent memory for Southern California. There’s an 80% chance downtown Los Angeles will get 2 or more inches of rain from Tuesday through Christmas Day. The last time downtown got 2 or more inches of rain over Christmas Eve and Christmas Day was in 1971.

Here’s what you need to know.

Timing

The peak of the system is expected Tuesday through Thursday, according to the National Weather Service.

There’s an 80% to 100% chance of rain in Los Angeles, Ventura, Santa Barbara and San Luis Obispo counties starting Tuesday night and lasting into Wednesday and Thursday.

In Orange County, the Inland Empire and San Diego County, light showers are possible Tuesday, but the heaviest rainfall is expected Wednesday, with officials warning of heavy rainfall, increased flooding risks and possible mudslides. Flood and mudslide risks will continue Thursday.

Expected effects of the storm for Orange County, the Inland Empire and San Diego County.

(National Weather Service)

Worst-case scenario

Forecasters are warning that there’s a 40% chance of “very high” amounts of rain for Los Angeles, Ventura and southern Santa Barbara counties, and a 30% chance of the same for northern Santa Barbara County and San Luis Obispo County.

That scenario would see 4 or more inches of rain fall on the coast and in the valleys, with 8 or more inches in the mountains and foothills, Tuesday through Thursday. Peak rainfall rates would be half an inch to 1 inch per hour.

According to the National Weather Service, that could cause:

• Significant mudslides
• Flooded freeways
• Streams and rivers flooding over their banks
• Localized flooding that could rise above curbs and into homes and businesses
• Moderate coastal flooding in south-facing areas
• Downed trees and power lines
• Dangerous sea conditions
• Swiftwater rescues

Rainfall probabilities for Los Angeles, Ventura and southern Santa Barbara counties.

(National Weather Service)

Between Tuesday and Thursday, numerous areas have a high chance of seeing 3 or more inches of rain. There’s a 77% chance of that occurring in Anaheim and Yorba Linda, a 74% chance in Santa Ana, a 73% chance in Ontario, a 71% chance in Mission Viejo, a 69% chance in Irvine, a 68% chance in Chino, a 65% chance in Laguna Niguel and a 60% chance in San Clemente.

Rainfall probabilities for northern Santa Barbara County and San Luis Obispo County.

(National Weather Service)

Advertisement

‘High amounts’ of rain scenario

There’s also a 40% chance of “high amounts” of rain in L.A., Ventura and southern Santa Barbara counties, and a 50% chance of the same in northern Santa Barbara and San Luis Obispo counties. That scenario would entail 2 to 4 inches of rain falling along the coast and in the valleys, with 4 to 8 inches in the mountains and foothills.

Rain to that extent would risk flooding freeway lanes; causing minor coastal flooding, mudslides and debris flows; and potentially force swiftwater rescues in fast-moving rivers and streams.

Wind

There’s a potential for gusty winds from the south, said Robbie Munroe, meteorologist with the National Weather Service’s Oxnard office, which issues forecasts for L.A., Ventura, Santa Barbara and San Luis Obispo counties.

That risks toppling trees and power lines. On Tuesday night, Los Angeles could see peak gusts of 31 mph; Woodland Hills, 38 mph; Paso Robles, 52 mph; and San Luis Obispo, 53 mph.

“Avoid parking under trees,” the weather service said. “Secure loose outdoor objects.”

There’s a 65% chance of gusts exceeding 35 mph in Huntington Beach, a 60% chance in San Diego, a 45% chance in Big Bear Lake and Ramona, a 40% chance in Escondido and a 35% chance in Riverside, according to the weather service office in San Diego.