A ‘noticeable’ cooldown is coming, even as Bay Area heat wave hits 100s one final time – Monterey Herald
A ferocious Bay Area heat wave that set records and swallowed up with ease the region’s natural coolant will cease to reign over the region on Friday.
Just how powerful was it?
“The far interiors and the usual really hot places will probably still see triple-digits Friday, but you’re not going to see any 115s or 110s,” National Weather Service meteorologist Sarah McCorkle said. “It’s going to be a cooldown that’s noticeable, even in the hottest places.”
The forecasted highs Friday will be in the usual spots. In Brentwood, the thermometer is expected to reach 107 degrees, a five-degree cooldown from its high mark of the heat wave. Livermore, which twice reached a Bay Area-record high of 116 during the heat blast, is expected to be 103 on Friday. Morgan Hill is expected to peak at 100, nine degrees lower than Thursday and 10 below its highest mark of the week.
Elsewhere, the figures are expected to be more mild: San Jose is expected to reach 93, Oakland 81 and San Francisco 72.
The slight relief is expected to help the state’s electrical grid, but a Flex Alert remained in place for the 10th consecutive day. The California Independent System Operator, which oversees the grid, put the alert into place from 4-9 p.m. and projected a state usage of 46,669 megawatts. The state used a record 52,061 megawatts on Tuesday.
The air also was expected to be a bit more healthy, and the Bay Area Air Quality Management District replaced a Spare the Air alert with an advisory. An alert had been in place for the previous five days.
Another sign of the heat wave’s strength is that it’s taking two systems to bring it down. The weather service said the new air masses created from Tropical Storm Kay in the Gulf of Mexico and a trough moving down from Alaska have finally punctured the high-pressure bubble.
“Those systems are working together to squish the high pressure,” McCorkle said. “It’s a very dynamic weather pattern that’s going on right now. The trough to the north is normal, but to see a tropical system moving up from the south at the same time? We don’t see that often.”
One result will be the return of the natural cooling influence the marine layer provides. The marine layer itself had been crushed by the high pressure that brought the heat wave.
The other result is that a light amount of rain may fall Friday in areas of Monterey and San Benito counties, McCorkle said. There’s also about a 10% chance for light rain in the region starting late Saturday afternoon into Sunday.
Come Saturday, the expected high temperatures in the hottest places are expected to dip by 10-15 degrees from Friday, and in the slightly-less-hot spots will be down 7-10 degrees, according to the weather service. Cities closer to the coast won’t see as much of a dip.
On Monday, seasonable air and temperatures will return, and the weather service said that pattern should remain for at least several days.
“It’s going to be nice to see and feel that,” McCorkle said.