SAN DIEGO -- Santa Ana winds, above-average temperatures and dry conditions are expected to combine Wednesday to increase the risk of wildfires across San Diego County.
A National Weather Service red flag warning for the inland valleys and the mountains will remain in effect until 8 p.m. Thursday. Forecasters said "critical fire weather conditions" would hit San Diego County by mid-morning Wednesday.
"A combination of strong winds, low relative humidity and warm temperatures will contribute to extreme fire behavior," according to the weather service.
Northeast winds of 15 to 30 miles per hour with gusts of 40 to 50 mph are expected. Forecasters said the strongest winds would blow through and below mountain passes and into portions of the valleys.
"Moderate to locally strong Santa Ana winds will create critical fire growth conditions Wednesday and Thursday," according to the weather service.
Motorists were advised that blowing dust may skew visibility, and the winds may make for difficult driving conditions, especially for those in high profile vehicles.
The winds are expected to weaken somewhat Wednesday evening, but will ramp back up early Thursday, then weaken Friday, however, hot and dry conditions will persist into the weekend.
Forecasters said high temperatures could be as much as 15 to 20 degrees above average west of the mountains, and 5 to 10 degrees higher than normal elsewhere in the county. Several locales could see temperatures push into the 90s.
High temperatures Wednesday are expected to range from 81 to 86 degrees at the beaches, 86 to 91 degrees inland, 90 to 95 in the western valleys, 84 to 89 near the foothills, 75 to 84 degrees in the mountains and 89 to 94 in the deserts. On Thursday, they'll be 87 to 92 degrees along the coast, 92 to 97 inland, 93 to 98 in the western valleys, 88 to 93 near the foothills, 79 to 88 in the mountains and 91 to 96 in the deserts.
Any fires that do develop will likely spread rapidly and outdoor burning is not advised, forecasters said.