It's been a wild weather roller coaster in California the past two weeks, with a heat wave breaking for rain.
"We flipped a switch," says Matt Mehle, lead meteorologist for the San Francisco area's National Weather Service station in Monterey. "It's a dramatic switch between record-breaking heat to much-needed rainfall."
Monterey recorded 1.02 inches of precipitation in the 24-hour period from 8am Sunday, Sept. 18 to 8am Monday, Sept. 19. Salinas recorded 0.06 inches.
The heaviest rainfall was in the high peaks of Big Sur, which typically get more precipitation than the surrounding area, sometimes over a foot in big winter storms, Mehle says. "Out of the entire Bay Area, the mountains above Big Sur ended up with the highest totals. That part of our county actually gets a lot of rainfall, and that watershed can handle a lot of rainfall. It's not uncommon."
An NWS gauge at a remote mountain location at Mining Ridge recorded 4.33 inches in the same 24-hour period, and 3.78 inches at Three Peaks. A coastal Big Sur station further north recorded 1.65 inches.
A gauge on the Big Sur River monitored by the U.S. Geological Survey shows the river flow surged from about 9 cubic feet per second to nearly 45 feet per second Sunday night.
Caltrans officials closed Highway 1 from Point Lobos in the north to Ragged Point in the south amid a heavy downpour around 11:30pm Sunday night, due to flooding. That road closure prompted Carmel Unified School District to close Captain Cooper School in Big Sur on Monday, with many staff unable to travel there and to assess the road and entry for safety.
As of 8:45am Monday, Highway 1 has reopened to through-traffic.
The slow-moving storm system, located off the coast of Point Arena, roughly the Mendocino and Sonoma county line, is moving slowly to the northeast and predicted to continue to deliver showers to Monterey County over the next day or so, Mehle says.
The forecast calls for an additional 0.08 inches in Monterey today, and another 0.02 inches tonight.
While it's early in the rainy season, Mehle says it's not uniquely early, but the contrast to the recent heat wave makes this storm stand out. "It's not atypical for this time of year," he says.
Given the recent heat and fires in other parts of the state, he adds: "This rain is much-needed given fire weather concerns. By no means is this going to end fire season, but it's a step in the right direction."