The October heat wave that has baked the inland Bay Area is about to end abruptly. National Weather Service forecasters say a fast cooldown, strong winds and rough water are on the way for the weekend, which happens to be when crowds gather along San Francisco's waterfront for the Fleet Week air shows.
From 100 degrees to a jacket
Livermore has hit 100 degrees every day since last Saturday, and much of the interior has been in the 90s, according to SFGATE. NWS Bay Area meteorologist Dylan Flynn told the outlet that "a drastic change is coming." By Saturday, highs are expected to fall to around the 70s inland and to the upper 50s and low 60s near the coast.
Flynn said three weather systems are combining to bring the change: a dip in the jet stream toward Northern California, a weak low-pressure system moving in from the west by Thursday, and the remnants of Hurricane Rachel drifting up from the south.
What it could mean for the Blue Angels
Northwest winds of up to 30 mph could start as early as Friday afternoon, peak Saturday and ease by Sunday. That falls short of the roughly 39 mph usually needed for a wind advisory, but forecasters are watching closely. Flynn also pointed to offshore winds and a southerly swell with waves of 10 to 12 feet, and said some disruption to the program is possible, though he noted he isn't the expert on flight operations. The weather service is coordinating with the U.S. Coast Guard on safety.
There is some good news for spectators: the wind may clear out the coastal fog overnight Thursday, and any clouds should move through quickly. Flynn's advice to anyone heading out is to dress warmly. Opening ceremonies are set for 12:15 p.m. Friday, with the Blue Angels scheduled to fly at 3 p.m. This year's shows mark the team's return to Fleet Week after last year's government shutdown, SFGATE noted.
King tides without a storm
A coastal flood advisory is set to run from 9 a.m. Friday through 3 p.m. Tuesday, with a little over a foot of water expected in low-lying shoreline areas. The new moon is behind the high tides, but Flynn said El Niño and warmer ocean water have pushed tides about a foot above normal. He told SFGATE he had never seen a foot of storm surge on a sunny day before a storm arrived, and that the region is "very likely to break some records come November."
Watch for smoke, too
Separately, the Bay Area Air District issued an advisory saying smoke from the Lucas Fire in Lake County may drift over the region. The district expects most of the smoke to stay aloft and does not expect pollution to exceed the federal 24-hour health standard, so no Spare the Air alert is in effect, but it said hazy skies and occasionally unhealthy air are possible through Saturday. Residents can check conditions on the EPA's Fire and Smoke Map.