A red flag warning signifying a high risk of wildfire remained in force Wednesday in the San Gabriel Mountains and the Angeles National Forest amid high heat, low humidity and an overabundance of very dry vegetation.
Virtually all of L.A County was under a red flag warning until Tuesday, when it was canceled everywhere except the San Gabriels and the forest.
But the National Weather Service said in a statement that even though no red flag warning is in effect in much of L.A. County, “the combination of continued very warm temperatures, low humidity, locally gusty south-to-southeast winds, and very dry fuels will maintain elevated fire weather concerns through Thursday.”
In the mountains, where the red flag warning remains in effect until 10 p.m. Wednesday, southwest winds of 10-20 miles per hour are expected, along with 30-mph gusts, amid humidity levels of only 5-15 percent and a temperature of 104.
“A Red Flag Warning means that critical fire weather conditions are expected,” according to the statement. “A combination of strong winds, very low relative humidity, hot temperatures, and very dry fuels can contribute to extreme fire behavior.”
It said that “if fire ignition occurs, conditions are favorable for very rapid fire spread … and extreme fire behavior, which would threaten life and property.”
Also canceled in most of L.A. County was an excessive heat warning, although it was left in place until 8 p.m. Wednesday in the Antelope Valley, where a high of 108 is expected, and the NWS said the region’s heat wave, which began Monday, would last through Friday.
The prevailing conditions create an “increased potential for serious heat-related illnesses, especially for the young and elderly, those performing outdoor activities, as well as those without access to air conditioning,” warned an NWS statement.
“Take extra precautions if you work or spend time outside,” including frequent breaks, the statement urged. “When possible, reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear light weight and loose-fitting clothing when possible and drink plenty of water.”
Most important, never leave children, seniors or pets in parked vehicles, even with windows cracked open, as a vehicle’s interior temperature can quickly turn deadly.
Where temperatures will fall a tad Wednesday, NWS forecasters credited a stronger onshore flow than was recorded earlier this week.
Along the coast, a coastal hazard message, which is a little less serious than a high surf advisory, will go into effect Thursday as a result of a southeast-to-south swell generated by Hurricane John south of Cabo San Lucas.
“The combination of long period swell and high tides will bring a risk of minor coastal flooding to low lying areas, especially Friday evening when the highest surf and highest tides are expected. In addition, there will likely be strong frequent rip currents,” warned an NWS statement. “Minor coastal flooding is possible over low-lying coastal areas such as beach parking lots and harbor walkways. No significant damage is expected. Dangerous rip currents and powerful breaking waves are likely.”
Surf of 6-9 feet is expected.
The NWS forecast sunny skies in L.A. County Wednesday and highs of 80 degrees in Avalon; 83 at LAX; 89 in Long Beach and on Mount Wilson; 91 in Downtown L.A.; 93 in San Gabriel; 94 in Burbank; 95 in Pasadena; 101 in Saugus and Woodland Hills; 104 in Palmdale; and 105 in Lancaster. Temperatures will rise around five degrees in some communities Thursday but dip marginally in others, then remain mostly in the high 80s and low 90s through Tuesday.
In Orange County, sunny skies were forecast along the coast but smoke is expected in the air in inland communities as a result of the Holy fire in the Cleveland National Forest. Highs will be 81 in San Clemente; 82 in Newport Beach and Laguna Beach; 93 in Anaheim and Irvine; 94 in Fullerton and Mission Viejo; and 96 in Yorba Linda. Temperatures will rise Thursday, then retreat a few degrees on Friday, after which highs will remain in the high 80s and low 90s at least through Tuesday.