LOS ANGELES (CNS) — A red flag warning signifying a risk of wildfire has gone into effect in parts of the Southland, and fire weather conditions will threaten the region through Saturday, Oct. 8, amid strong Santa Ana winds, low humidity and very dry vegetation, forecasters said.

The red flag warning will be in effect until 3 p.m. Saturday in the Santa Clarita Valley, the San Gabriel Mountains in Los Angeles and Ventura counties, L.A. County’s Angeles National Forest and the Los Padres National Forest in Ventura County. A sharp drop in humidity levels is expected in those areas beginning this afternoon, forecasters said.

North winds between 20 and 30 miles per hour in the red flag zone, gusting to between 40 and 50 mph, will begin to weaken today, Oct. 6. At the same time, the humidity will fall to 15 per cent in the afternoon, then to single digits tonight.

A  fire weather watch, which is less severe than a red flag warning, will be in force through Saturday afternoon in the San Fernando Valley, the Santa Monica Mountains, inland areas of Orange County and the valleys of Ventura County.

These areas will be swept by north-to-northeast winds of between 15 and

25 mph, gusting to between 30 and 40 mph. Humidity levels will dip into the single digits Thursday through Saturday.

“During this time, there will be rapid drying with single-digit humidity becoming common across the higher elevations,” according to a National Weather Service statement. “Thursday through Saturday, gusty Santa Ana winds will bring significant warming and drying to much of Los Angeles and Ventura counties.”

Forecasters said the strongest winds are likely to occur Friday, Oct. 7,with gusts between 35 and 45 miles per hour possible in mountain and valley areas.

“The combination of gusty offshore winds, warm temperatures, low humidity and very dry fuels (vegetation) will likely bring critical fire weather conditions,” the statement said. “Any fire ignitions will bring the potential for rapid fire spread along with extreme fire behavior.”

L.A County temperatures will climb Thursday — by as much as 10 degrees in some communities — and by another several degrees on Friday, beginning a cooling trend Sunday, Oct. 9.