Additional rainfall keeps a flood and mudslide threat going through at least Tuesday. Heavy snow continues to blanket the mountains, pushing some totals perhaps as high as 10 feet over a handful of days. There could even be snow at the coast in northern California as snow levels plummet Monday night.
The first of the two storms that slammed into California over the weekend was a powerhouse. Born just off the West Coast, it drove ashore near peak intensity. Its minimum pressure of 980 millibars was comparable to a Category 1 or 2 hurricane (the lower the pressure, the more intense the storm).
Downtown San Francisco picked up 1.59 inches of rain through Sunday, with higher totals in the hills around the region, particularly just to the south where numbers are generally in the two-to-three-inch range.
All this rain has caused flash flooding, river flooding and mudslides.
Among other issues, the rain and resulting mess led to a closure of portions of the Pacific Coast Highway as well as Highway 101 for a time over the weekend. Evacuation orders were issued for some of the recently burned areas around Malibu in Southern California, although residents have since been allowed to return home. Other areas that saw fires in 2018 faced similar concerns.
On Saturday, damaging wind was reported from Northern California and the southern parts of the state. The National Weather Service office serving the Bay Area reported velocities near 100 mph a few thousand feet above sea level. Additionally, “winds knocked down power lines in Santa Barbara County on Saturday and reached 89 mph in Los Angeles County,” according to USA Today.
Another round of major wind gusts rolled through the San Francisco Bay area in the predawn hours Monday, and gusty conditions are anticipated until the second storm system passes.
Multiple feet of snow
A blizzard warning remains in effect through late Monday night for the mountain chain. The Weather Service office in Reno warns: “Strong winds will produce zero visibility and whiteout conditions along with high drifting snow.” It advises no travel because of “a dangerous and life threatening situation.”
Four to eight feet of snow is the general expectation from the snow events above 7,000 feet, which means some spots could approach 10 feet. The heavy snow comes in tandem with winds as high as 100 mph on ridges and to around 50 mph lower in the mountains.
So far, Mammoth Mountain in the central Sierra has picked up as much as 81 inches. And the snow continued to fall at a rate of several inches per hour rates Monday. The June Mountain ski area was buried under so much snow, 108 inches, that it shut down Monday. Many nearby areas had received three or four feet from these storms.
The Southern California mountains are also picking up big totals.
For the first time since 2011, snow may also end up falling at very low elevations around the San Francisco Bay area Monday night, thanks to a cold pocket of air in the upper atmosphere. It drops out of the Pacific Northwest and into California, leading to this risk. The hills around the city seem likely to be coated in white, and there might be snow to beach level across the north.
This portion of the storminess has already been responsible for a “surreal scene in #Seattle” Monday morning according to the Seattle Weather Blog. Snow there got a hashtag trending Monday morning on Twitter. Enough snow fell for Tracy Taylor, a traffic reporter in the region, to write that thoroughfares in the city were the snowiest in over a decade.
Once this storm system moves out by midweek, another seems likely to drop into the Pacific Northwest late in the workweek, possibly delivering more rain and snow to the region. Details become less certain further out in time, but a pattern that could remain wetter than normal seems probable into the midmonth or beyond.