Temperatures will drop sharply

A National Weather Service meteorologist described the weather as “a roller coaster ride in terms of temperatures,” and Wednesday's drop in temperature is likely to be dangerous.

However, this does not mean that the hot season is finally over this year.

“Tuesday through Wednesday, it will be about 10 to 15 degrees cooler,” meteorologist Matt Mehle said Tuesday. “But that doesn't mean it will be cold on Wednesday. It's just a return to normal temperatures. It should be great weather.”

All of this is like saying the small hills on the roller coaster are “easier” than the long, high, steep drops. Temperatures across the region are not expected to rise above 80 degrees on Wednesday. A heat advisory for the East Bay Hills and inner valley was set to expire at 8 p.m. Tuesday.

The cooling process had already begun in some parts of the region on Tuesday. In San Jose, the temperature was 90 degrees at midday and was expected to reach a high of 92 degrees. This makes Morgan Hill the hottest place in the South Bay. On Monday, the high was 95 degrees.

Temperatures in and around Oakland were around 76 degrees at midday and are expected to be around 80 degrees, similar to San Mateo (78, 81) along the peninsula. San Francisco also recorded 75 degrees at midday and is expected to reach 78. Those temperatures accompanied humidity above 50%, the weather service said, making it a bit uncomfortable but far cooler than the far East Bay.

Temperatures rose inland. In Brentwood, the thermometer showed 92 degrees at midday and was on its way to the expected 100 degrees. In Livermore, it showed 95 degrees, where 99 degrees had been forecast. In Concord, the midday temperature was 91 degrees and was expected to peak at 97 degrees. In Pleasanton, it was 95 degrees and will probably reach 97 degrees.

“We've definitely had heat waves in the past in late September and early October,” Mehle said. “So it's definitely not unusual for there to be another heat wave.”

Next comes the jump.

According to the weather service, temperatures in Livermore will not rise above 85 degrees on Wednesday, in Concord and San Jose they will not rise above 80 degrees, in Oakland they will not rise above 70 degrees and in San Francisco they will not rise above 65 degrees.

Starting Thursday, those temperatures will start to rise again, and Friday is expected to be hot again. The weather service predicts that the hottest spots in the East Bay will again reach temperatures above 95 degrees, and the hottest spots in the South Bay will reach just above 95 degrees.

This warming is expected to be followed by more moderate temperatures on Saturday, similar to those of Wednesday. The arrival of a low pressure system from the Pacific Northwest will bring with it the marine layer that has been eroded and crushed by the high pressure that caused the recent heat.

The return of the marine layer and the weakening of the high pressure area that is rebuilding in the middle of the low pressure area will together ensure that the heat will only last for a very short time at the end of the week, Mehle said.

“I expect the weather this weekend to be such that people will want to move here,” he said.

Originally published: September 24, 2024 at 7:33 am