Heat Wave Sends Temperatures 15-20 Degrees Above Normal

The heat wave gripping the Southland will gain strength today amid temperatures in the high 90s and low 100s, sustaining an elevated risk of wildfire and creating severe health risks, especially for the elderly.

“An upper level ridge of high pressure will build over the area this weekend, setting the stage for an extended period of heat for Southwestern California,” the National Weather Service said in a statement. “Afternoon temperatures will begin to climb today and Saturday as the onshore flow will be very weak.”

Temperatures will be 15-20 degrees above normal for this time of year, NWS Meteorologist Joe Sirard said. What the NWS calls a “decent heat wave” began Thursday.

“There is going to be some triple-digit heat Friday into Saturday and more widespread on Sunday,” when some record or near-record highs are forecast, Sirard said.

The heat wave is not expected to include high winds, a key ingredient in sparking and spreading wildfires, according to the NWS. Still, the combination of dry air and high temperatures will “bring elevated fire danger to our region,” Sirard said.

“If any fire does break out it could still be pretty nasty and probably spread pretty quickly with the heat, but it would be worse with high winds, which we are not expecting at this time,” he said.

Relative humidity levels are expected to range between 10 and 20 percent and even dip into the single digits in some valley, mountain and desert areas, Sirard said.

The heat creates health risks, according to the NWS.

“The extended period of hot weather will bring an increased risk of heat-related illnesses through early next week,” warned the NWS statement. “Residents without air conditioning -- especially the elderly -- will be at risk for heat-related impacts.”

The NWS warned residents to protect themselves and their pets against dehydration, heat stroke, heat exhaustion, heat cramps, and hyperthermia. It issued a set of five instructions on its website:

-- Drink plenty of water and not alcohol or coffee.

-- Avoid strenuous activities when it’s hot.

-- Wear light clothing and spend more time in air-conditioned places.

-- Do not leave children or pets unattended in vehicles, which can quickly turn into virtual ovens.

-- Provide pets with plenty of shade and water.

The Orange County Health Care Agency released a statement, also urging local residents to take caution.

“Prolonged exposure to excessive temperatures may cause serious conditions like heat exhaustion or heat stroke and can even be fatal,” according to the statement. ”Symptoms of heat exhaustion may include heavy sweating, muscle cramps, weakness, headache, nausea or vomiting and dizziness.”

Warning signs of heat stroke may include an extremely high body temperature, unconsciousness, confusion, hot and dry skin (no sweating), a rapid, strong pulse, and a throbbing headache. If symptoms of heat stroke occur, immediately call for medical assistance. Move the person to a shady area and begin cooling their body with water.

The NWS forecast highs today of 78 in San Clemente; 81 in Newport Beach; 86 in Laguna Beach; 93 in Anaheim, Irvine and Yorba Linda; 94 in Fullerton; and 95 in Mission Viejo.

The forecast calls for temperatures to rise by two or three degrees Saturday, by about the same on Sunday, then, on Monday, to begin a slow cooling trend that will gain strength Tuesday.

The dry weather will dissipate precipitously next week. Moisture from Tropical System Odile will begin to stream into the region Wednesday and Thursday, bringing a chance of showers and thunderstorms to local mountains and the Antelope Valley, according to an NWS hazardous weather outlook statement.

Additionally, large swells from Odile may generate high surf and dangerous rip currents at Southland beaches, it said.

--City News Service

Patch Senior Editor Penny Arévalo contributed to this report.

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