A blast of relief from the heat and humidity of the past two days arrived Wednesday morning with the onset of rain, thunder and lightning in parts of the region — and those elements were taking their sweet time as they traveled north.
“It’s drifting slowly,” National Weather Service meteorologist Dylan Flynn said. “As it tapers off, we may get a break in the late afternoon (Wednesday), but there could be another regeneration Wednesday night into Thursday morning.”
Related Articles
Amid a Bay Area sizzle, dry lightning concerns continue to loom
Bay Area weather expected to be a carbon copy of previous week
Bay Area dodges thunderstorms, humid weather on the horizon
Threat of Bay Area dry lightning lessens as hot spell begins to fade
Bay Area heat to return briefly, but dry lightning looms as threat
The rain’s arrival overnight came as predicted along the coast in Monterey and San Benito counties. Remnants from a tropical storm in the southern Pacific Ocean off the coast of Mexico has sent moisture north since late last week, and that moisture has mixed with higher pressure up north that’s been responsible for the heat.
That said, the moisture in the current pattern is more significant, and Flynn said more than a quarter-inch to a half-inch of rain was expected in the Central Coast. It was accompanied by “hundreds of lightning strikes,” Flynn said.
Lightning will remain a threat as the storm moves north, even as the heavy rain does not. Flynn said that unlike on Tuesday, forecasters on Wednesday expect rain with lightning to fall in Santa Cruz and Santa Clara counties, as well as in Alameda and Contra Costa counties, though the amount of rain that comes with it will decrease as the storm gets away from the Central Coast.
“It looks like the best chance for these thunderstorms to maintain will be in the South Bay and East Bay,” Flynn said. “As they get there, they’ll be a little drier. In the South Bay and East Bay, you’re looking at (rainfall) totals of tenths of inches, maybe hundredths. Combine that with the lightning and that’s always a fire concern.”
The storms could linger into Thursday, according to the weather service. Flynn said that the storm eventually is expected to spin around, and gather moisture from the northeast.
“We won’t be out of the woods for rain probably until midday Thursday,” he said.
On Tuesday, Livermore hit 100 degrees; Concord, Pleasanton and Morgan Hill each got to 99; San Jose reached 95 and Oakland was 88 on Tuesday. A cool down followed. The hottest spots set to peak between 83 and 85 degrees Wednesday, with humidity levels continuing to hover around 50%.
Those temperatures are expected to stay mostly mild, save for a one-day spike on Friday that is likely to take the hottest spots into the low 90s. By Monday, more rain might be in the works, courtesy of a developing system in the Pacific Northwest.