A record high 115 degrees Tuesday in Manteca-Ripon-Lathrop brought California precariously close to being forced into rolling blackouts.

Manteca based on the nearest National Weather Service station at Stockton Metro Airport, hit the 115 degree mark at 4:35 p.m. and stayed there until 5:10 p.m.

By 5:45 p.m. as peak temperatures hit in Modesto (112 degrees), Stockton (114 degrees), Sacramento (116 degrees), Tracy (113 degrees), Sonora (109 degrees), Redding (112 degrees),  Fresno (113 degrees), and Furnace Creek in Death Valley (123 degrees) the California Independent System Operator issued a Stage 3 Flex Alert.

That meant if people didn’t scale back on their electrical use sections of the state would initially be sent into blackouts to prevent demand from causing a systemwide failure on the power grid.

Such systemwide failures often take six hours or more to bring the power back on line.

Peak electricity demand on Tuesday hit 52,061 megawatts, far above the previous high of 50,270 megawatts set on July 24, 2006.

In Manteca, several high school sporting events were postponed.

That included the Sierra-Manteca tennis match at the Manteca Regional Tennis Center where temperatures on the playing surface approached 120 degrees at 3:35 p.m.

The forecast for today calls for 107 degrees and 111 degrees on Thursday. On Friday, on what is expected to be the 10th  and final day of the heat wave, temperatures are forecast to reach 107 degrees.

Due to that, some games are having their start times postponed.

East Union High will start their JV football game in Atwater Friday at 5 p.m. and the varsity at 8 p.m. — an hour later than normal.

Meanwhile, East Union freshmen will host their Atwater counterparts on Thursday at 7 p.m. instead of 6 p.m.

Last Friday’s Lathrop at Weston Ranch football game started an hour later as well on what was the second day of the current heat wave where highs have soared past 100 degrees.

By declaring a Stage 3 emergency, the power system operators were able to call on emergency power sources — basically non-green power plants — to meet the demand triggered in part by people turning on air conditioners to stay cool as they arrived home from work.

Large power users such as Verizon took rare moves to reduce stress on the grid.

They did so under provisions of the Stage 3 alert that allowed them to activate permanent backup generators to power six of its California mobile switching stations.

In addition, through Sept. 12, Verizon is raising the temperature in all of its California retail stores statewide, reducing the total HVAC usage by one hour, and lowering shades.

Ways that residents can reduce power use today and through at least Friday to prevent a system collapse or rolling blackouts is to:

*Delay doing dishes and  laundry until after 9 p.m.

*Turn thermostats to 78 degrees

*Unplug unused devices.

More tips can be found at  www.flexalert.org

As demand swelled the call went out with everyone from Gov. Gavin Newsom to the state's legal marijuana business control agency urging people to turn off lights and reduce power or use backup generators.

While there were no rolling blackouts over large areas, two outages were reported in the San Francisco Bay Area cities of Palo Alto and Alameda, affecting several thousand customers for about an hour.

Demand fell as evening fell, businesses closed and dropped sharply after CAISO sent out a message on its mobile phone app begging customers to cut back their use, warning that "power interruptions may occur unless you take action."

The Stage 3 alert ended at 8 p.m. without major rotating outages. CAISO tweeted that "consumer conservation played a big part in protecting electric grid reliability."

Even without intentional blackouts, however, tens of thousands of people found themselves without power in Northern California.

Some 35,700 people lost electricity in Silicon Valley and southern and inland areas of the San Francisco Bay Area and most of the outages were heat-related, said Jason King of Pacific Gas & Electric said Tuesday evening. There was no word on when power would resume.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com