Triple-digit weather was expected to bake parts of the Southland again Sunday, with the Antelope Valley and Santa Clarita Valley likely to bear the brunt of the high-pressure system and the state urging energy conservation to prevent outages.
An excessive heat warning is in effect in the Antelope Valley through 9 p.m. Monday, with the National Weather Service predicting “dangerously hot conditions with temperatures up to 113 expected.”
Forecasters said temperatures won’t drop dramatically overnight in the area, with lows expected in the mid-70s to mid-80s.
“Strong upper level high pressure will bring excessively hot temperatures to the interior valleys, mountains and deserts through early next week, with above normal temperatures most everywhere away from the coast,” according to the NWS.
Forecasters said the excessive heat warning could potentially be extended to the Santa Clarita Valley, depending on how the high-pressure system unfolds. For the time being, the NWS issued a less severe heat advisory for the Santa Clarita Valley that will be in effect until 9 p.m. Sunday, with temperatures up to 105 degrees expected.
A heat advisory will be in effect until 9 p.m. Monday for Los Angeles County mountains, excluding the Santa Monica range. Forecasters said lower elevations could see temperatures of up to 106 degrees.
A continuing onshore flow will keep temperatures cooler along the coast.
Fear of wildfires always accompanies heat waves. Forecasters said humidity levels could drop into the teens in the mountains and interior areas. And gusting winds are likely in the afternoons, particularly in the Antelope Valley.
“As a result, there will continue to be elevated fire weather conditions in the afternoons across the drier and windier locations,” according to the NWS.
Meanwhile, the California Independent System Operator, which manages the state’s power grid, declared a Flex Alert — a call for voluntary conservation in hopes of reducing strain on the system and preventing outages — from 4 to 9 p.m. Friday and Saturday.
Cal-ISO officials urged residents to set their thermostats to 78 degrees or higher during the alert, avoid using major appliances and turn off all unnecessary lights. Residents should also consider pre-cooling their homes before the alert takes effect and use window coverings to keep rooms cool.
Cal-ISO also issued a “restricted maintenance operation” for Saturday, calling on power suppliers to defer planned maintenance that would impact electrical supply.
While the weather is expected to be hot, forecasters said temperatures would likely remain just shy of daily record levels, which are in the 110-115 range, and “certainly short of all-time records which are in the 113-117 range.”
A cooling trend is expected Tuesday that will bring temperatures down to near normal levels for the rest of the week, though triple-digit temperatures are still expected throughout the week in the Antelope Valley.
As with other heat events, the NWS advised residents in the Antelope Valley to stay hydrated, avoid the sun when possible and check up on relatives and neighbors who might be susceptible to heat illness.
“Take extra precautions if you work or spend time outside,” forecasters advised. “When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible.”
The Los Angeles County Department of Public Health issued an extreme heat warning through Tuesday in the Antelope Valley, and through Monday in the Santa Clarita and western San Fernando valleys.
A county heat alert will be in effect Sunday in the western San Gabriel Valley and eastern San Fernando Valley.
County officials said those without air conditioning at home can take advantage of cooling centers, with information on locations available at ready.lacounty.gov/heat/ or by calling 211.
L.A. County residents can take solace in the fact that this weekend’s high temps are still well short of the eye-popping numbers recorded in Death Valley. The Mojave Desert location — known for the Earth’s hottest recorded temperature of 134 degrees in 1913 — reached a high of 130 degrees on both Friday and Saturday, and was expected to hit 130 again Sunday.