Early signs of a cooldown from the hottest part of the Bay Area’s weekend heat wave were apparent Sunday, according to the National Weather Service, even if it may not have felt that way. The Bay Area did not receive its usual overnight blast of cool air, some inland areas still hit at least 100 degrees, and an excessive heat warning remained in place.
Yet those upper-level wispy clouds were ever-present, a sign that relief was en route after an intense 72-hour blast.
“We already are seeing a pattern shift,” NWS meteorologist Matt Mehle said Sunday morning. “That high pressure that brought the heat is gonna start to be nudged a bit east. It’s going to be replaced by an area of low pressure that’s coming down from the Pacific Northwest. We’re gonna get the tail end of that, and that’s gonna bring us back down.”
On Sunday, temperatures were expected to run 3-5 degrees cooler than they did Saturday in most places in the region, and they’re expected to drop another 3-5 degrees again on Monday, according to Mehle. On Tuesday, the region is expected to be back at its average early July temperatures, with overnight temperatures in the 40s and low 50s, and daytime highs in the hottest places in the 80s.
That said, the final day of the weekend was still scorching hot in parts of the East Bay, following overnight lows that ran in the 60s in most places and in the 70s in the upper elevations, Mehle said. Many areas went past 100 on Saturday, but Mehle said the heat did not set any records.
“It might be a few degrees down, but your body is gonna be working just as hard to stay cool, because of how it was overnight,” he said.
Brentwood in far east Contra Costa County was the hottest place in the region Sunday afternoon, with temperatures reaching 106 degrees at 3:15 p.m. after soaring to 105 on Saturday. In Livermore, often the hottest place in Alameda County, the gauge reached 104 on Saturday and was at 102 Sunday afternoon. In Morgan Hill in the South Bay, the temperature was 91 degrees about 3:15 on Sunday, a day after hitting 100.
In Walnut Creek, the temperature Sunday afternoon reached 99, a day after hitting 98. San Jose, which reached 92 on Saturday, was 94 degrees on Sunday afternoon. San Mateo, along the Peninsula, on Sunday reached 79 at about 3:15 p.m. Sunday, Oakland was about 71 and San Francisco was a relatively cool 66 degrees.
“The hottest locations are still going to be very hot,” Mehle said, adding that temperatures in Brentwood and Livermore were being influenced by heat from the Sacramento Valley, where temperatures were expected to peak at 107.
The Central Valley had areas expected to reach 110 degrees (Fresno was forecast to hit 111) Sunday, but that was balmy compared with Death Valley, where visitors flocked in anticipation of reaching 131 degrees for the first time in Earth’s recorded history. But as of Sunday afternoon, the temperature in Death Valley was hovering around 125 degrees with partly cloudy skies.
Closer to the Bay Area, safety officials continued to call for constant hydration and limited physical exertion, at least until Monday. The heat advisory, in place since 11 a.m. Saturday, was set to expire at 11 p.m. Sunday.
By Monday night, at least in the North Bay, there could be another concern, Mehle said. Upper level winds are going to become more southerly, meaning they could “tap into some moist air in Southern California” and bring some unstable, stormy air, he said.
The weather service’s focus is on areas north of the Golden Gate Bridge along the coast, he said.
“Of course, if thunderstorms develop,” Mehle said, “then lightning becomes the concern.”
Source: www.mercurynews.com