Backyard barbecues, swimming and outdoor sports could be on the schedule this week for Bay Area residents getting a hotter-than-average start to early spring.
A ridge of high pressure building off the coast was moving inland Tuesday, ushering in widespread warm conditions this week and pushing temperatures around 10 to 20 degrees above normal for this time of year, according to the National Weather Service. The heat wave, strengthened by the offshore flow, could break record temperatures along the Peninsula and in the South Bay, where the majority of the heat will be focused Wednesday.
Locations for potential record-breaking highs Wednesday include Santa Rosa, whose last record was 84 degrees in 1926; Richmond, with a high of 75 degrees in 2015; the San Francisco International Airport, with a high of 73 degrees in 1970; and Redwood City, with a previous record of 79 degrees in 1931. In the South Bay, records could also be broken in San Jose, which last had a high of 83 degrees in 1926, and in Gilroy, whose last record was 81 degrees in 1977.
“There’s a bit of a southern bias for some of these,” said forecaster Brayden Murdock. “There’s going to be a lot that’s approaching (breaking records.)”
Wind gusts were expected to range between 20 to 35 miles per hour, with the strongest force in the higher elevations, including Mount Diablo and Mount Saint Helena. The winds were expected to continue through Tuesday morning before lessening by the early afternoon.
Vulnerable people and pets should avoid or be kept out of parked cars, where the high temperatures could turn deadly, according to the weather service. People were also advised to wear light-colored clothing, avoid outdoor activities in the afternoon and to stay hydrated.
By Thursday, the high-pressure ridge is expected to weaken and bring a five to 10-degree cool-down for the inland valleys. Cooling is expected to continue into the weekend before approaching below-average daytime highs on Sunday into the high 50s and 60s. An approaching trough could move southward over the eastern Pacific Ocean, pulling more air from the sea in the form of onshore flow and bringing rain chances back into the forecast early next week.
“Things are hard to pin down right now because it’s too far out,” Murdock said. “Right now it doesn’t look terribly strong but it could lead to a nice cooldown. We could definitely use the moisture.”
A storm over the weekend — the final one of the winter — delivered about one-tenth of an inch of rain to the North Bay and San Francisco, with about 0.15 to 0.2 inches in the Santa Cruz Mountains and just under 0.1 inches in the Santa Clara Valley. The Sierra Nevada got anywhere from two to four inches of snow, with the highest elevations getting up to six inches.
“Spring is where we start to see transition where rain chances become fewer and fewer. It’s good we had another batch of rain come through — we had two in the last two weeks,” Murdock said. “As far as rainfall amounts go, it was a pretty common spring rain to come through. Not a huge amount of rainfall but still a good amount for a few certain areas, especially high elevations, did very well.”
Large atmospheric river storms in October and December raised hopes of ending California’s drought, which is going into its third year, but January and February were the driest on record dating back to 1921. The statewide Sierra Nevada snowpack, which fulfills about 30% of the state’s water needs, was at 168% of normal on New Year’s Day but shrunk down to 52% as of Tuesday, according to the California Department of Water Resources.
The high temperatures and dry air have also raised concerns for fires sparking in Northern California. Wildfires have ignited during what would be the wettest time of the year, raising concerns for a year-round fire season. Fuels and vegetation have dried out and require storms with higher precipitation totals to fill them up again.
“As far as fire concerns go, we’re doing better this year than last year,” Murdock said. “We had one atmospheric river storm January 2021 and a few chances for rain but that was our big rain event. This year, we had those big storms in October and January and we’ve been coasting on that for a while. We do still have our concerns — when you see a ridge of high pressure, we keep an eye on winds and dry conditions because when you see warmer and dryer air come through, we do see those fire fuels start to get dryer and dryer as well.”
The U.S. Drought Monitor reported Thursday that 93% of California is in “severe drought”, an increase from 87% from a week ago, while 35% of the state is in “extreme drought,” the most dire stage, up from 13%. Extreme drought has reached the North Coast and all nine Bay Area counties are currently in a severe drought.
Gov. Gavin Newsom also said Friday that the State Water Project, a massive system of pipes, canals and dams that provides water to 27 million people across the state, will deliver 5% of the water that was contracted to farms and cities, down from 15% in January.
“The rains we’ve been getting, it’s not gonna put too much of a dent in how dry we’ve been,” Murdock said. “But it’s good to see some beneficial rain passing through the area.”
Source: www.mercurynews.com