The section of Highway 1 in Monterey County was washed out into the ocean following debris flow, flooding and mudslides near the San Luis Obispo County line.
California Highway Patrol officers in Monterey County shared a photo of the highway on social media.
It's unclear how long it will take to repair the roadway. In the meantime, the highway is closed, and drivers are asked to take alternate routes.
A CHP officer who was patrolling this area described what he saw. "Yesterday (Thursday) around 4 p.m., I was in the area, when I noticed this section of roadway, specifically the southbound lane, had fallen off into the ocean," said Ofc. John Yerace. "I stayed in the area until I was relieved last evening. Around 6 p.m., the roadway still consisted of a northbound lane. Some time overnight, prior to 6:30 in the morning, we responded back to the scene with the assistance of Caltrans access and realized that the roadway is now gone."
The washout looks incredible, but the CHP urged drivers to stay away.
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Forecasters said the "atmospheric river event'' had already dropped nearly 14 inches of rain in some parts of San Luis Obispo County throughout Wednesday and Thursday and Los Angeles County could see 1.5 to 3.5 inches of rain, with 2 to 5 inches possible in the foothills and mountains.
"On Friday, numerous showers, mountain snow showers and a slight chance of thunderstorms can be expected as a cold upper-level low pressure system affects the region,'' according to the NWS. "Dry weather will prevail Saturday through Monday as high pressure builds in over the region.''
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City News Service contributed to this report.