The latest Bay Area heat wave is expected to crest Friday, with temperatures in many places likely to surpass or at least threaten 100 degrees, according to the National Weather Service. Then just as quickly, the dial will dip about 10 degrees to start a two-day cooldown that the weather service said will span the weekend.
Following that comes another heat up with the peak of that one happening on Tuesday before another significant dip 72 hours after that.
If the thermometer seems to have been moving up and down like a teeter-totter recently, it’s not your imagination.
“Remember how in the winter, it seemed like every other storm that hit us seemed to be less than a week since the previous one?” NWS meteorologist Brayden Murdock said Friday. “That’s what we have now. Global weather is on about a 6- to 6 1/2-day timeline where there’s an oscillation of the pattern. As the jet stream stays where it is, we have the building of high pressure ridges and then low pressure in between.”
That’s a weather pattern that has filled the region for much of July, Murdock said. It produced a historical heat wave early in the month and is responsible another forceful one now.
“With this one, we’re not getting as strong a high pressure as we had previously,” Murdock said, adding that the slightly weaker high pressure has kept the highest temperatures this week cooler than they were at the peak of the heat wave earlier in July.
That said, the weather service expected it to be mighty hot on Friday. A heat advisory that started Thursday remained in effect Friday for the much of the East Bay and South Bay, as did an air quality advisory. Smoke from wildfires across Northern California will have an effect on the air, officials said.
In Brentwood — about as far into the interior of the region as it gets — the thermometer is expected to reach 105 degrees. It’s forecast to be 102 in Concord, generally the hottest place in central Contra Costa County, as well as in Livermore, Alameda County’s hottest spot.
In Santa Clara County, temperatures are expected to max at 99 in Morgan Hill, and San Jose is forecast to peak at 92.
Even the spots next to the water will be warmer than usual. San Mateo is forecast to reach 82, as is Oakland. San Francisco is expected to hit 75.
The temperatures in the hottest places all are expected to dip by about 10 degrees on Saturday and then a couple of more on Sunday, before the needle starts to creep up again on Monday.
“As of right now, Monday looks to be pretty warm and then Tuesday is probably going to be the warmest,” Murdock said. “It’ll stay warm even though it’ll start to cool on Wednesday, but the big relief is going to be Friday going into next weekend.”
As July gives way to August, Murdock said the weather pattern is expected to have changed enough that all remnants of the high pressure that created the hot July will be gone.
“As we get into August, we’re anticipating close to average temperatures or just barely above,” he said. “We just gotta get there.”
