Scores of residents were urged to flee as fast-moving fires hurtled through bone-dry brush in Bonsall and Mission Valley Tuesday

Red flag warnings are in effect until Thursday for parts of Los Angeles, Ventura and San Diego due to low humidity and relentless Santa Ana winds.

The Los Angeles haven’t spread in nearly a week, but the return of the Santa Ana winds to full strength could cause problems.

San Diego County remains under the grip of another round of moderate to strong Santa Ana winds, paired with extremely dry air, elevating critical fire weather concerns.

Forecasters say the third windstorm of January will focus much of its energy on the region during one of the driest periods on record.

Wildfires in Southern California prompt evacuations and school closures as Santa Ana winds exacerbate conditions. Communities remain on high alert.- Watch Video on English Oneindia

Wildfires in San Diego have led to mandatory evacuations in the area on Tuesday. Officials tell FOX News that two wildfires are burning in San Diego County, with strong Santa Ana winds creating "dangerous fire conditions." RELATED: Why are winter wildfires happening in Southern California?

"A Red Flag Warning means that critical fire weather conditions are either occurring now, or will shortly," the NWS said.

Scores of residents were urged to flee as fast-moving fires hurtled through bone-dry brush in Bonsall and Mission Valley Tuesday

Several counties in Southern California faced "critical" fire risks this week, according to an AccuWeather forecast.

Santa Ana winds will continue whipping through Southern California through Thursday, sparking fears that progress made fighting wildfires that have scorched over 40,000 acres and left 28 dead could be reversed and more blazes could break out.