SLO County on alert for coastal flooding with high tides, rain forecast for Christmas Day

Just in time for Christmas, the weather is taking frightful turn — with rain and high tides that carry a threat of coastal flooding.

On Monday, the National Weather Service issued a high-surf advisory that will last until 9 a.m. Wednesday.

A long-period northwest swell will bring high surf to the Central Coast through Monday evening, with another large westerly swell arriving arriving late Christmas Eve into Christmas Day, the NWS said.

The agency also warned that an “astronomical” high tide late Christmas morning could cause some coastal flooding and beach erosion.

Surf is forecast to build to 9 to 12 feet with sets up to 14 feet on Tuesday morning along the Central Coast, the NWS said. The surf will then gradually subside through Wednesday morning.

Coinciding with the high surf is a storm front that will bring rain and chilly temperatures to San Luis Obispo County, according to PG&E meteorologist John Lindsey.

A fast-moving low-pressure system is dropping from Northern California into the Central Valley from Christmas Eve into Christmas morning, Lindsey said. The system will bring cooler temperatures and rain showers — plus northwesterly winds that will reach speeds between 25 and 38 mph.

There’s also a chance of thunderstorms the night of Christmas Eve, Lindsey said.

Total rainfall amounts are expected to rain between a tenth of an inch to a half-inch, according to Lindsey.

Skies will clear back up again on Wednesday, which will be a warmer day, Lindsey said.

But heading into the weekend, the Central Coast may see some of the coldest days and nights so far this winter: lows in the North County are expected to drop into the mid- to high 20s on Friday and Saturday, according to Lindsey.

Warmer temperatures and strong to gale-force winds at speeds between 25 to 38 mph are expected through the end of the year, with long-range models showing a wet start to the new year, Lindsey said.

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