LOS ANGELES (CNS) - Temperatures are expected to slowly decline in Southern California by day and night but uncomfortable humidity is expected to increase, the National Weather Service said.
Temperatures hit triple-digits today around the Southland, including 100 degrees in downtown Los Angeles, 101 in Burbank, 103 in Pasadena and 108 in Palmdale and Lancaster, according to National Weather Service meteorologist Carol Smith.
No records were broken by day, but there could be "record high lows" overnight, Smith said.
Overnight temperatures were expected to range from 75 to 80 in Los Angeles, and 78 to 84 in the valleys.
Humidity was expected to increase Sunday to 43 to 53 percent in the L.A. Basin and 30 to 40 percent inland, Smith said.
The higher humidity was blamed on moisture from Tropical Storm Lidia in Mexico's Baja California Peninsula, she said.
While temperatures Sunday are expected to be lower than today, the increase in humidity will keep people sweating, Smith said.
Sunday temperature estimates include 93 degrees in downtown Los Angeles, mid-80's in coastal areas and mid-to-upper 80's in the valleys, she said.
They will trend down a few degrees more Monday before starting up again Tuesday while humidity declines a little.
With the tropical moisture comes an increased chance of thunderstorms and dry lightening in the area starting overnight, Smith said.
Some storms could be heavy and cause flash flooding in burn areas, she said.
Rain could help firefighters battling the brushfire in the La Tuna Canyon area but dry lightening could start more fires.
The dry lightning was possible overnight and showers were more likely Sunday afternoon.
Excessive heat warnings will remain in force until 10 p.m. Saturday night in the San Fernando, Santa Clarita, San Gabriel and Antelope valleys, the San Gabriel and Santa Monica mountains at lower elevations, what NWS forecasters call the coast, which includes beach cities, metropolitan L.A and the Hollywood Hills.
An excessive heat warning also will be in effect in Inland Orange County today. A less serious heat advisory will be in force at the same time in the county's coastal communities.
"Some cooling is expected Saturday, but temperatures will still be well above normal and all the current advisories and warnings will continue through at least Saturday evening," forecasters said.
The California Independent System Operator, which manages the state's power grid, issued a statewide Flex Alert that will be in effect until 10 p.m., calling for voluntary electricity conservation. "Consumers are urged to conserve electricity especially during the late afternoon when air conditioners typically are at peak use," according to Cal-ISO, which issued a Flex-Alert previously once this week -- on Tuesday.
Despite that call, the Los Angeles Department of Water and Power set a record for the second consecutive day for peak electricity demand. The demand reached a peak of 6,555 megawatts mid-afternoon Friday, besting the record of 6,502 set on Thursday.
Strain on the system continued to lead to power outages. As of 5 p.m. Friday, about 9,300 DWP customers were without power.
The weather service again urged area residents to protect themselves and their loved ones from such heat-related illnesses as heat strokes by avoiding strenuous work in high heat, staying hydrated, wearing lightweight, light-colored clothing, checking on friends and neighbors -- especially the elderly -- and by never leaving children, seniors or pets in cars parked in hot weather, even for a short time and even with windows cracked open.
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