A heat wave that already has produced record highs this week will generate more health-threatening temperatures across the Southland today. Temperatures are expected to be a few degrees lower Saturday and fall some more over subsequent days.
The high temperatures have prompted an appeal to residents to use air conditioning judiciously and conserve electricity through the weekend to avoid blackouts.
The appeal came in the form of a ``flex alert'' -- an urgent call for residents to conserve -- issued by the California Independent System Operator, which manages the state's power grid. The lowest on Cal-ISO's rung of emergency
declarations, the ``flex alert'' will be in effect today through Sunday.
There is a "critical'' need for residents throughout the state to cut their power usage, particularly between the hours of 11 a.m. and 6 p.m., because energy demand is expected to be high throughout the weekend, Cal-ISO said in a statement.
As was the case Thursday, an excessive heat warning issued by the National Weather Service to indicate oppressively high temperatures will be in force today from 11 a.m. until 8 p.m. in the San Gabriel, San Fernando and Santa Clarita valleys and the mountains of L.A. County -- both the San Gabriels and Santa Monicas.
The warning reflects that "the combination of hot temperatures and high humidity will combine to create a dangerous situation in which heat illnesses are possible,'' according to the NWS.
The NWS forecast highs today of 102 degrees Farenheit for Baldwin Park.
The above-normal daytime and overnight temperatures are the result of a hot air mass caused by a ridge of high pressure over the Southwestern United States, according to the NWS.
"Daytime temperatures well above 100 degrees across inland areas will be common through Saturday,'' according to an NWS advisory.
There will be a slight chance of afternoon and evening thunderstorms today and Saturday in the Antelope Valley and the San Gabriel mountains in Los Angeles and Ventura counties, NWS forecasters said.