As a Christmas week storm is expected to heavy downpour across Southern California, mud and debris flows as well as floodwaters shut down roadways and blocked freeway lanes Wednesday.

Drivers were urged to exercise the utmost caution on roadways on Christmas Eve or Christmas Day.

A flash flood warning will be in place until 6 p.m. Wednesday for the bulk of Los Angeles County.

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MANHATTAN BEACH, CALIFORNIA - DECEMBER 23: People are reflected in a puddle along the Manhattan Beach Pier decorated with Christmas lights, as a storm descends on Southern California December 23, 2025 in Manhattan Beach, California. (Photo by Jay L Clendenin/Getty Images)

MANHATTAN BEACH, CALIFORNIA – DECEMBER 23: People are reflected in a puddle along the Manhattan Beach Pier decorated with Christmas lights, as a storm descends on Southern California December 23, 2025 in Manhattan Beach, California. (Photo by Jay L Clendenin/Getty Images)

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The 5 Freeway in Sun Valley was shut down Wednesday as the lanes became heavily flooded.

The 5 Freeway in Sun Valley was shut down Wednesday as the lanes became heavily flooded.

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A intersection near Colorado Boulevard and Monte Bonita Drive was flooded in Eagle Rock.

Carl Schumacher

A intersection near Colorado Boulevard and Monte Bonita Drive was flooded in Eagle Rock.

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Officials urged Wrightwood residents to shelter in place due to heavy mud and debris flows.

San Bernardino County Fire

Officials urged Wrightwood residents to shelter in place due to heavy mud and debris flows.

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Fire crews responded to an Altadena neighborhood to clean up a mudflow.

Fire crews responded to an Altadena neighborhood to clean up a mudflow.

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A stream of mud flooded a roadway in Altadena.

A stream of mud flooded a roadway in Altadena.

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OXNARD, CA – DECEMBER 24: Flooded intersection at Hill and G streets in Oxnard on Wednesday, Dec. 24, 2025. (Myung J. Chun / Los Angeles Times via Getty Images)

OXNARD, CA – DECEMBER 24: Flooded intersection at Hill and G streets in Oxnard on Wednesday, Dec. 24, 2025. (Myung J. Chun / Los Angeles Times via Getty Images)

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A man checks the damage caused by driving through a flooded road on La Cienega Boulevard on December 24, 2025 in Los Angeles, California. A major winter storm rolled into California on December 23, forcing hundreds of evacuations in burn areas while threatening flooding and travel delays through Christmas for much of the state, officials said.<br /> A “strong atmospheric river brings heavy rain, snow, and wind to California through Friday,” the National Weather Service said in a statement on December 23, warning anyone in northern, central and southern parts of the state to “exercise extreme caution.” (Photo by Apu GOMES / AFP via Getty Images)

A man checks the damage caused by driving through a flooded road on La Cienega Boulevard on December 24, 2025 in Los Angeles, California. A major winter storm rolled into California on December 23, forcing hundreds of evacuations in burn areas while threatening flooding and travel delays through Christmas for much of the state, officials said.
A “strong atmospheric river brings heavy rain, snow, and wind to California through Friday,” the National Weather Service said in a statement on December 23, warning anyone in northern, central and southern parts of the state to “exercise extreme caution.” (Photo by Apu GOMES / AFP via Getty Images)

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VENTURA, CA – DECEMBER 24: A play area at Ventura Beach RV Resort in Ventura, CA is flooded on Wednesday, Dec. 24, 2025. The resort was under an evacuation order as a precaution. In 2023, the site flooded with hip-deep water from nearby Ventura River. (Myung J. Chun / Los Angeles Times via Getty Images)

VENTURA, CA – DECEMBER 24: A play area at Ventura Beach RV Resort in Ventura, CA is flooded on Wednesday, Dec. 24, 2025. The resort was under an evacuation order as a precaution. In 2023, the site flooded with hip-deep water from nearby Ventura River. (Myung J. Chun / Los Angeles Times via Getty Images)

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VENTURA, CA – DECEMBER 24: Workers clean up fallen debris at Ventura Beach RV Resort in Ventura, CA on Wednesday, Dec. 24, 2025. The resort was under an evacuation order as a precaution. In 2023, the site flooded with hip-deep water from nearby Ventura River. (Myung J. Chun / Los Angeles Times via Getty Images)

VENTURA, CA – DECEMBER 24: Workers clean up fallen debris at Ventura Beach RV Resort in Ventura, CA on Wednesday, Dec. 24, 2025. The resort was under an evacuation order as a precaution. In 2023, the site flooded with hip-deep water from nearby Ventura River. (Myung J. Chun / Los Angeles Times via Getty Images)

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SANTA MONICA, CA  – DECEMBER 24, 2025 Bianca Brown, from right to left, and her son Rylen Adams, from Las Vegas, have their picture taken by Elena Esparza as Bianca’s father, Brian Brown, left, looks on as an atmospheric river storm rains on the Santa Monica Place in Santa Monica on December 24, 2025. A flood watch was issued for Tuesday afternoon through Wednesday evening for much of Los Angeles County, with mud and debris flows possible across foothill and mountain areas, including recent burn scars, according to the National Weather Service.(Genaro Molina/Los Angeles Times via Getty Images)

SANTA MONICA, CA  – DECEMBER 24, 2025 Bianca Brown, from right to left, and her son Rylen Adams, from Las Vegas, have their picture taken by Elena Esparza as Bianca’s father, Brian Brown, left, looks on as an atmospheric river storm rains on the Santa Monica Place in Santa Monica on December 24, 2025. A flood watch was issued for Tuesday afternoon through Wednesday evening for much of Los Angeles County, with mud and debris flows possible across foothill and mountain areas, including recent burn scars, according to the National Weather Service.(Genaro Molina/Los Angeles Times via Getty Images)

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City workers try to remove a tree that felt on a wall next to the Hollywood Water Reserve on December 24, 2025 in Los Angeles, California. A major winter storm rolled into California on December 23, forcing hundreds of evacuations in burn areas while threatening flooding and travel delays through Christmas for much of the state, officials said.<br /> A “strong atmospheric river brings heavy rain, snow, and wind to California through Friday,” the National Weather Service said in a statement on December 23, warning anyone in northern, central and southern parts of the state to “exercise extreme caution.” (Photo by Apu GOMES / AFP via Getty Images)

City workers try to remove a tree that felt on a wall next to the Hollywood Water Reserve on December 24, 2025 in Los Angeles, California. A major winter storm rolled into California on December 23, forcing hundreds of evacuations in burn areas while threatening flooding and travel delays through Christmas for much of the state, officials said.
A “strong atmospheric river brings heavy rain, snow, and wind to California through Friday,” the National Weather Service said in a statement on December 23, warning anyone in northern, central and southern parts of the state to “exercise extreme caution.” (Photo by Apu GOMES / AFP via Getty Images)

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Heavy rain is seen from Kenneth Hahn Park blocking the view of the city skyline on December 24, 2025 in Los Angeles, California. A major winter storm rolled into California on December 23, forcing hundreds of evacuations in burn areas while threatening flooding and travel delays through Christmas for much of the state, officials said.<br /> A “strong atmospheric river brings heavy rain, snow, and wind to California through Friday,” the National Weather Service said in a statement on December 23, warning anyone in northern, central and southern parts of the state to “exercise extreme caution.” (Photo by Apu GOMES / AFP via Getty Images)

Heavy rain is seen from Kenneth Hahn Park blocking the view of the city skyline on December 24, 2025 in Los Angeles, California. A major winter storm rolled into California on December 23, forcing hundreds of evacuations in burn areas while threatening flooding and travel delays through Christmas for much of the state, officials said.
A “strong atmospheric river brings heavy rain, snow, and wind to California through Friday,” the National Weather Service said in a statement on December 23, warning anyone in northern, central and southern parts of the state to “exercise extreme caution.” (Photo by Apu GOMES / AFP via Getty Images)

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SANTA PAULA, CA – DECEMBER 24: Joseph Macias of Santa Paula, watches the Santa Clara River flow from South Mountain Road in Santa Paula, CA on Wednesday, Dec. 24, 2025. (Myung J. Chun / Los Angeles Times via Getty Images)

SANTA PAULA, CA – DECEMBER 24: Joseph Macias of Santa Paula, watches the Santa Clara River flow from South Mountain Road in Santa Paula, CA on Wednesday, Dec. 24, 2025. (Myung J. Chun / Los Angeles Times via Getty Images)