Heat wave to continue through Wednesday in SoCal; red flag warning issued

At the peak of a Southland heat wave, the National Weather Service Monday issued a red flag warning effective through Thursday for the San Gabriel Mountains in Los Angeles and Ventura counties and the foothills in the Antelope Valley, citing high heat, low humidity, dry conditions and the expectation of high winds.

The warning, which denotes a heightened risk of wildfire, will take effect at noon today and remain in force through 9 p.m. Thursday. It is the first red flag warning issued since the region's heat wave began Saturday.

Even though the heat wave has been projected to end Wednesday, forecasters said an "elevated fire danger'' will exist in inland areas through Thursday because a hot and dry air mass is parked overhead, and an onshore flow will generate gusty winds.

According to the NWS, the hot air will remain in place through mid-week, its presence coinciding with the strengthening flow. The coast will cool down, but "all interior sections of Southern California will continue to see elevated fire danger,'' forecasters said.

The most critical fire weather conditions will occur across the mountains of Los Angeles and Ventura counties and the foothills in the Antelope Valley -- areas where the presence of "extremely dry fuels'' contributes to "critical red flag conditions,'' according to the NWS.

Onshore winds will churn up strong gusts in the mountains, and even stronger gusts in the Antelope Valley through Thursday evening, according to the weather service. At the same time, single-digit humidity levels will prevail, dipping to as low as 3 percent, with little improvement even at night, it said.

NWS forecasters said southwest winds of between 15 and 25 mph, gusting to 35 mph, will sweep the San Gabriels daily through Thursday, blowing the strongest in the afternoon and evening. Stiffer winds are expected in the Antelope Valley -- between 20 and 30 mph, gusting to 45 mph, weakening at night, when it will blow at between 10 and 20 mph, with gusts of 25 mph.

No other red flag warnings were immediately issued, but the NWS again warned that an "elevated fire danger'' will persist in interior sections of Santa Barbara County and some foothill areas, according to the NWS.

The heat wave is the result of an upper-level high-pressure system combined with weakening onshore flow, the NWS said. Temperatures in Los Angeles and Orange counties will rise today, reaching triple digits across the Antelope, Santa Clarita and San Fernando valleys and the San Gabriel Mountains at lower elevations and the foothills. They will decline a few degrees over the coming days beginning Tuesday.

"The prolonged heat wave will likely result in an increased risk of heat-related illnesses, especially for the homeless, elderly, infants and anyone participating in outdoor activities,'' according to the NWS.

Forecasters urged residents to stay well-hydrated, wear light-colored lightweight clothing, stay indoors when temperatures are at their highest and never leave people or pets in parked vehicles in hot weather, even for a short time. People with heart disease, asthma or other respiratory diseases who live or work in high-heat areas are especially urged to minimize outdoor activities.

The NWS forecast sunny skies today and highs in Los Angeles County of 79 in Avalon; 80 at LAX; 89 in downtown L.A.; 90 in Long Beach; 93 on Mount Wilson; 95 in San Gabriel; 97 in Burbank; 99 in Pasadena; 102 in Saugus and Palmdale; 103 in Lancaster; and 105 in Woodland Hills. Sunday's high in Woodland Hills was 102.

Sunny skies were also forecast in Orange County, along with highs of 79 in Newport Beach; 81 in San Clemente; 83 in Laguna Beach; 91 in Anaheim and Irvine; 94 in Mission Viejo; 95 in Fullerton; and 98 in Yorba Linda.

Temperatures will be around three degrees lower Tuesday, stay the same or drop another couple of degrees Wednesday, then remain roughly at the same level for a few days more.

In downtown L.A., for example, the seven-day NWS forecast shows highs of 89 today, 85 Tuesday, 83 Wednesday, 81 Thursday, 79 Friday, 81 Saturday and 82 Sunday. At the same time, Woodland Hills' highs, 105 today, are forecast to be 101 Tuesday, 97 Wednesday, 94 Thursday, 92 Friday, 94 Saturday and 95 Sunday.

Yorba Linda, currently Orange County's warmest community, is forecast to have a high of 98 today, 95 Tuesday, 91 Wednesday, 90 Thursday, 88 Friday and Saturday, and 89 Sunday.

The Department of Public Health recommends that Southern Californians stay safe during the heat wave by:

Additionally, the NWS notes that anyone overcome by the high temperatures should call 911 because heat stroke is an emergency.

Here are links to area cooling centers:

CLICK HERE FOR A FULL LIST OF COOLING CENTERS ACROSS L.A. COUNTY

CLICK HERE FOR A FULL LIST OF COOLING CENTERS ACROSS ORANGE COUNTY

CLICK HERE FOR A FULL LIST OF COOLING CENTERS STATEWIDE

The agency also reminds residents they should never leave people or pets in enclosed vehicles, even for a few minutes.

Besides not leaving animals in a parked car, city animal services officials say pet owners must make sure their animals are kept cool during the heat wave.

Pet owners should watch for signs of heat stroke, such as fast and noisy breathing, difficulty swallowing and distressed behavior.

If heat stroke is suspected, pet owners should place a cold, wet towel on the back of the animal's head, and towel-wrapped cold compresses on their back legs and belly. The pet should be immediately taken to a veterinarian to be checked.

Other tips include:

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