An unseasonal storm system brought snow to higher elevations of California on Monday, May 18, 2020, while thunderstorms developed through the foothills, as well as the Sacramento and San Joaquin Valleys on Tuesday, May 19. According to the National Weather Service (NWS), the origin of the storm is an unusually deep and cool upper-level low-pressure area off the California-Oregon border.
Morning snow accumulated in the Sierra Nevada reportedly caused havoc with roads around Donner Summit and on I-80 on Monday. Chain restrictions on the interstate were eventually lifted the next day.
"Flakes are flying," said meteorologist Drew Tuma. "While it's weird that we are talking about snow this late in May, it's not unusual to get these light storms moving through the Sierra as we end our snow season."
A winter storm warning was in effect until midnight Monday, with snow levels dropping to around 1 829 m (6 000 feet).
It's snowing in Tahoe right now.— Drew Tuma (@DrewTumaABC7) May 18, 2020
That's the tweet.
Sierra at tahoe before it snowed more on top of it. Guess 6”+ pic.twitter.com/o3dusn5QHc— Andrew Bray (@mtnwallaby) May 19, 2020
I-80 eastbound at Kingvale this morning. pic.twitter.com/wFdrmv0aXq— CHP - Gold Run (@CHPGoldRun) May 18, 2020
The snow continued into Tuesday, with winter weather advisories issued through the afternoon as the storm brought moderate snow showers to the region.
"If you can believe it, we have snow in the forecast for the mountains of California," said Fox News senior meteorologist Janice Dean.
The storm system also prompted flash flood watches for the Sacramento and northern San Joaquin Valleys. Wind advisories were in effect for the latter's western region and planned for Southern California's interior mountains.
As of Wednesday, May 20, temperatures have started to warm up as the cool weather system moved out of Southern California.
According to NWS's forecast, it will be mostly clear and sunny into Friday morning, May 22, but it will be partly cloudy and breezy in the evening. The weather will then be normal into the weekend.
Featured image credit: CHP Gold Run