Atmospheric river will blast California with heavy rain and snow ‘measured in feet’ [heading to CO]

Discussion in 'Lake Powell Recreation' started by Waterbaby, Jan 4, 2017.

  1. Waterbaby

    Waterbaby Administrator Staff Member

    If this holds up it could be good news for Utah and Colorado mountains, too. This is shades of the late 60's, early 70's...‘measured-in-feet’/ar-BBxRnaL?li=BBnbfcL

    Atmospheric river will blast California with heavy rain and snow ‘measured in feet’


    A river of atmospheric moisture will flow over California through the weekend.

    California is getting the rain and snow it needs this week thanks to a shift in the weather, and the region’s meteorologists are finally calling it “normal” for winter on the West Coast. Through the weekend, up to two feet of water could rain down on the high elevations of the Golden State. If the majority of that moisture falls as snow, it could mean over 10 feet of snow along the Sierra Nevada peaks.

    The ridge of high pressure that has been in place for days is moving east, and a strong low pressure system that formed in the Gulf of Alaska is taking its place. As winds flow counterclockwise around the low, they pull tropical moisture northeast from the Pacific Ocean — an atmospheric river that will pour down over much of California in the coming days.

    Rain and snow will be heavy at times, especially in the northern Sierra Mountains, where winds from the west will be forced to flow over high terrain. As air rises, the water vapor (humidity) will condense into clouds and precipitation.

    The National Weather Service is suggesting two feet of precipitation in the form of water could drench Northern California. In the cold high elevations, much of that will be frozen, which means multiple feet of snow.

    now levels are starting low — just 2,000-3,000 feet, according to the National Weather Service — but will rise as the air gets warmer later this week. Nearly three feet had already accumulated at Kingvale, Calif., (elevation 6,000 feet) as of Tuesday morning.

    “Three to four feet of snowfall accumulation can be expected above 4,500 feet with some areas possibly seeing 5 feet or more along the crest by Thursday,” the Weather Service wrote in a Tuesday morning discussion. “Needless to say, severe travel impacts are likely crossing the northern Sierra.”

    Travel is being discouraged in the northern Sierras until the storm lets up. Road closures for major thoroughfares, such as Interstate 80 and Route 50, are possible over the passes during the heaviest snowfall through Wednesday.
    NWS Sacramento @NWSSacramento

    Have travel plans across the mountains? You'll want to postpone a few days if you can! Here's a look at I-80. Expect very long delays #cawx

    8:56 AM - 3 Jan 2017

    By the weekend, the atmospheric river will shift south and bring rain to Southern California, a region that has been neglected by rain over the past year. While a large portion (around 15 percent) of Northern California saw drought relief in 2016, the southern half of the state was very dry up until December.

    “Los Angeles marked a sober milestone last year, when the NWS announced that the last five years were the driest ever documented in downtown L.A. since official record-keeping began almost 140 years ago,” wrote Angel Jennings in the L.A. Times Monday evening. The L.A. Times has provided unparalleled coverage of the region’s historic drought since it began in 2011. “Precipitation during that period totaled just 38.79 inches — roughly half of the normal amount.”

    Then, in a marked reversal, December turned out to be the wettest since 2010, and it looks like the pattern will stay wet through at least the beginning of next week. A few tenths of an inch of rain will fall across Southwest California through Friday, followed by a significant surge over the weekend.


    The National Weather Service in Los Angeles is cautioning that they do not know exactly where the heaviest rainfall will occur, but that “there is potential for a heavy rain event across portions of all of Southwest California sometime between Saturday and Monday, which could result in significant flash flooding with mud and debris flow issues, especially across the recent burn areas.”

    Daniel Swain @Weather_West

    Appears that two major #AtmosphericRiver events will occur over next 7d. Second one on Sat looks especially powerful. Sig. flood risk. #CAwx

    11:07 AM - 3 Jan 2017

    Even with all the travel headaches and flooding these storms will likely cause, Californians are welcoming the precipitation after years of drought and water restrictions.

    “This is what we’re supposed to be getting,” Johnnie Powell, a meteorologist at the National Weather Service, told the L.A. Times. “After six years of a drought, I love saying that. This is normal rain and snow that we’re supposed to be getting in December and January.”
  2. TheMarinator

    TheMarinator Active Member

    Excellent ! Now that baby needs to just park itself above wyoming and colorado for a month .

    Speaking of....... here in SLC we have been getting pounded with snow since xmas , I probably have 10 inches in my yard . I know this doesnt flow to Powell but sure seems like we are off to a great snow year .

    How are the Coloarado mountains doing ? The usual site I check out seems to not be working .

    Are the slow blowers working extra hard on the western slope ? I sure hope
  3. Bill Sampson

    Bill Sampson Well-Known Member

    I saw on the Mammoth Mountain website this morning that they have received 7 feet of snow in the last 2 days. North star at Lake Tahoe is claiming even more. Both resorts are bracing themselves for this weekend's storm. In Southern California we are welcoming this rain, although our drivers have forgotten how to drive on wet highways.