Following two excruciatingly dry months in Northern California, winter has finally arrived in the form of a massive “bombogenesis” storm. And while many of the attention remains on the significant snowfall in the mountains and road closures throughout NorCal, this storm quietly reached the record books on Tuesday.
Gorgeous GOES-17 imagery depicting explosively deepening surface low ("#BombCyclone") approaching West Coast near OR/CA border. Storm is generating hurricane-force winds offshore & gusts to ~70 mph along coast, as well as widespread lower elevation snow in OR & N. CA. #CAwx #ORwx pic.twitter.com/ccMdpMQT7A— Daniel Swain (@Weather_West) November 26, 2019
A bombogenesis storm, or “bomb cyclone,” is a rapidly intensifying weather system of low pressure that occurs when cold air collides with warm air over the ocean, which strengthens the system. While the weather phenomenon isn’t rare, it’s also something that isn’t seen in this area regularly. In fact, the storm’s low pressure brought numbers never before seen in California:
Pressure has bottomed out at around 28.69" at Crescent City, which is (unofficially) the lowest for California since records have been kept.— NWS Eureka (@NWSEureka) November 27, 2019
See for yourself: https://t.co/FcbR5VqPxs https://t.co/ZZ45IPlwJ0 https://t.co/YlpTyKIWQy
So what does low pressure mean?
“It means that this storm is extremely powerful, though low pressure by itself does not mean this is the ‘worst’ storm impact-wise,” said the National Weather Service. “Other storms in our region have produced higher wind gusts & heavier rain & snowfall, by carrying more moisture, energy, and other factors.”
With heavy winds, cold temperatures and heavy precipitation, this unseasonable storm is breaking with all sorts of precedent. The early reports show up to 18 inches of snow in the mountains, with more on the way Wednesday.
While the snow and winds in Northern California are nothing new, it’s rare we see a storm of this magnitude, especially in November. But now that the storm’s pressure have been gauged, we know we’ve never seen anything like it in the recorded history of California.
A little #GOES17 satellite eye candy for you on this Tuesday evening! An impressive low pressure system is moving onshore near the Oregon/California border and is bringing very strong winds and feet of snow the mountains! #orwx #cawx #BombCyclone pic.twitter.com/eeG5hqfxK7— NWS Seattle (@NWSSeattle) November 27, 2019