A Warm, Dry Santa Ana weather pattern over Thanksgiving - NWS San Diego

Santa Ana winds are in store for San Diego County late Wednesday night through Friday morning, where locations below passes and canyons could experience gusts over 50 mph, the National Weather Service said Tuesday.

“An expansive surface high pressure system will stretch from Nevada to Colorado … a pattern that supports a stronger east-west pressure gradient that would funnel the strongest winds through the passes of San Diego and Riverside counties,” the NWS said in a statement. “This is where the highest gusts appear most likely. The winds will remain fairly strong Thursday afternoon, then subside a bit in the evening.”

A wind advisory is in effect for parts of the county from 9 p.m. Wednesday to 10 a.m. Friday.

“Gusty winds could blow around unsecured objects,” the weather service said. “The combination of strong winds, low relative humidity and warm weather will result in several hours of critical fire weather conditions.”

Forecasters predicted sustained winds of 20 to 30 mph, with gusts of 50 to 70 mph possible in mountain passes and canyons resulting in a few hours of elevated to locally critical fire weather conditions. Higher gusts to 70 mph are possible in the mountains.

High temperatures in San Diego County on Thanksgiving are predicted to reach the lower 70s near the coast, mid 70s inland, upper 70s in the western valleys, mid 60s near the foothills, mid 50s near the mountains and lower 70s in the deserts, according to the weather agency.

Meteorologists said there is a 30-40% chance of rain and mountain snow Monday, when a trough of low pressure sweeps in from the Pacific Northwest.

City News Service contributed to this article.