Just in time for the Fourth of July, the first major heat wave of the summer will descend on the Southland starting Friday, with forecasters warning of “dangerously hot” conditions in some areas.
An excessive heat warning will be in effect from 10 a.m. Saturday through 8 p.m. Sunday in the Santa Clarita Valley and the Antelope Valley and foothills. Those areas could see temperatures of 100 to 112 degrees, according to the National Weather Service, which warned of the potential for heat-related illnesses.
A less-severe heat advisory will be in effect during the same hours in the western San Gabriel Valleys and the Golden State (5) and Antelope Valley (14) freeway corridors. Temperatures in those areas are expected to range from the mid-90s to 105 degrees.
The heat is the result of a building high-pressure system, which will bake inland areas. Beaches are expected to be popular destinations for the weekend, with forecasters noting that “a persistent marine layer and onshore flow” will keep temperatures down in coastal areas.
“Dangerously hot weather will develop over the interior valleys and mountains over the weekend as the high pressure center drifts over the region,” according to the NWS. “… Temperatures will warm to values between 10 and 20 degrees above normal across the valleys, mountains, and desert.”
Forecasters noted that in the hottest areas, overnight temperatures won’t offer much relief, falling only into the 70s to near 80 in some locations.
“While more sunshine will be prevalent and much warmer temperatures will develop away from the coast, the beaches will be mired in low clouds into the afternoon,” according to the NWS. “As a result, the warming trend will be moderated for the coastal areas.”
The high-pressure system is expected to dissipate beginning Monday, although temperatures should remain above normal for the Fourth of July holiday on Tuesday. More significant cooling is anticipated Wednesday and Thursday.
