Atmospheric rivers threaten California as state reels from deadly storm - Axios

A rainstorm causes flash-flooding successful San Carlos, California, Dec. 31. Photo: Tayfun Coskun/Anadolu Agency via Getty Images

Californians reeling from a deadly large tempest implicit the play are bracing for an adjacent much unsafe atmospheric stream event opening precocious Tuesday night.

Threat level: "To enactment it simply, this volition apt beryllium 1 of the astir impactful systems connected a wide standard that this meteorologist has seen successful a agelong while," the National Weather Service Bay Area bureau said successful a forecast treatment Monday.

— Excerpt from NWS Bay Area bureau forecast discussion

State of play: Evacuation and shelter-in-place orders were successful effect Monday successful parts of Sacramento County owed to flooded roads from the play tempest that deed Northern and Central California, causing wide powerfulness outages and the deaths of astatine slightest 2 people, per the Sacramento Bee.

• Multiple road closures remained successful spot crossed Sacramento County Monday owed to flooding.

Computer exemplary projection of the h2o vapor being transported into the West Coast connected Wednesday morning. Image: Scripps Institution of Oceanography.

By the numbers: The New Year's Eve tempest resulted successful San Francisco downtown experiencing its second-wettest calendar time connected record, with 5.46 inches of rain.

• The UC Berkeley Central Sierra Snow Lab successful the Sierra Nevada Mountains recorded 7.5 inches of snowfall successful conscionable 1 hour connected Dec. 31.
• The imaginable of different 6 to 12 inches of rain, and aggregate feet of further upland snow, has forecasters and exigency managers progressively concerned.

What to expect: The adjacent large tempest is expected to deed Northern California precocious Tuesday nighttime done Thursday, followed by much aboriginal successful the week.

• Winter tempest warnings, flood watches and precocious upwind watches are successful effect for overmuch of cardinal and bluish California, including San Francisco, San Jose and Sacramento.
• Winds could gust to 70 mph successful parts of the San Francisco Bay area, the Weather Service warns.
• Daniel Swain, a U.C.L.A. clime scientist, noted successful a Twitter post that a rapidly deepening aboveground low, oregon meteorological bomb cyclone, "will stay good offshore, but the associated lukewarm and acold fronts volition bring wide dense rainfall and beardown winds to Northern California aboriginal Wednesday.

• Swain said this tempest "would beryllium reasonably notable successful its ain right, arsenic it volition beryllium associated with an unusually well-defined lukewarm and acold frontal passages and an exceptionally moist and comparatively warm" atmospheric river.

Photo: National Weather Service/Twitter

For the record: Atmospheric rivers are potent but constrictive currents successful the aerial that tin transportation vast amounts of h2o vapor thousands of miles from the tropics to mid-and-northern latitudes.

• Wednesday's tempest impacts "will beryllium further elevated by information that soils are present saturated" passim astir of Northern California, with immoderate rivers moving precocious and progressive large flooding and levee breaks on Sacramento County's Cosumnes River, Swain said.
• This volition bring with it the menace of further flooding and imaginable landslides.

The bottommost line: Climate alteration is adding adjacent much moisture to atmospheric rivers, enabling them to dump higher rainfall and snowfall totals.

• California is inactive successful a semipermanent terrible drought, and recent studies person shown that clime alteration increases the likelihood of upwind whiplash events from drought to flood and backmost again.