Euclid Avenue caked with mud. Heavy rains are headed to San Diego on Christmas.
Euclid Avenue caked with mud. (Photo by Chris Stone/Times of San Diego)

San Diego County is in for a wet Christmas.

Four days of rain are expected to begin Tuesday, forecasters said today.

A flood watch will be in effect in the county from 4 a.m. Wednesday through 1 a.m. Thursday, the National Weather Service reported.

An atmospheric River is expected to bring widespread moderate to heavy rain, with the heaviest and most widespread rain expected late Wednesday morning into the evening, according to the NWS.

“Peak rainfall rates of 0.50 to 1 inch per hour are expected,” the NWS statement said. “Scattered locally heavy showers could continue into Thursday but impacts from
any additional rain are expected to be more localized.

Flooding caused by excessive rainfall is possible from late Tuesday night through late Wednesday night. Mountain and desert areas are expected to get the heaviest rainfall.

San Diego County’s coastal areas, valleys, mountains, and deserts will be affected, including the cities of Chula Vista, Poway, Oceanside, Carlsbad, San Diego, Santee, Julian, San Marcos, Pine Valley, Escondido, La Mesa, Vista, Encinitas, El Cajon, Borrego Springs, and National City.

Excessive runoff may result in flooding of rivers, creeks, streams and other low-lying, flood-prone locations.

“Those living in areas prone to flooding should be prepared to take action should flooding develop,” the NWS said.

The rain is expected to cease by Saturday, with cooler temperature lingering in the 60s next weekend.