The Red Flag Warning was set to remain in effect until 8 p.m. Tuesday for the valleys and mountains, including the Palomar and Descanso ranger districts of the Cleveland National Forest.
“A Red Flag Warning means that critical fire weather conditions are either occurring now, or will shortly,” according to the National Weather Service. “A combination of strong winds, low relative humidity and warm temperatures will contribute to extreme fire behavior.”
High temperatures are expected to be in the high 70s to low 80s in the valleys today but could hit triple digits by mid-week. Mid-60s to low 70s are expected to be the highs in the mountains, but temperatures could be in the high 80s Thursday and Friday, according to the NWS.
Forecasters said Sunday’s winds would stay mainly confined to around the coastal foothills and below passes and canyons in Orange and San Bernardino counties and on the Riverside County mountains’ north slopes, but the gusty Santa Ana winds would bluster into San Diego County Monday and Tuesday and would likely continue into Wednesday.
Northeast winds of around 15-25 mph with gusts of up to 45 mph are expected in San Diego County through Monday, but forecasters said they would give way to 20-30 mph sustained wind speeds on Tuesday with gusts of up to 55mph.
“Strengthening high pressure aloft along the West Coast and surface high pressure over the Great Basin will bring much warmer and drier conditions, along with gusty Santa Ana winds today through Wednesday,” according to the weather service.
Forecasters said the winds were expected to gradually weaken Sunday night, but will pick up again around dawn Monday with similar conditions possible Tuesday and Wednesday.
The strong Santa Ana winds were expected to diminish Thursday and Friday, although humidities will remain low, the NWS said.