Christmas Feast

Friday, December 19, 2014 at 6:58 am


A weak system moves in tonight with a few snow showers possible.  However, all eyes are on an atmospheric river event that will bring copious snowfall to the high elevations of the Wasatch during the Saturday night thru Monday night time frame.  Another, colder storm likely for Christmas Day!


Lots to talk about!  Let’s dive right in…

Friday night – Saturday morning: A weak shortwave will move through the region tonight.  It looks very weak on the models, but like we saw yesterday morning, these weak little guys can surprise us this time of year. Certain areas could pick up a quick couple inches of snow.

Saturday night – Monday night: A very persistent atmospheric river develops over the region.  This will bring copious moisture to the area for a long time frame.  Model QPF in the NAM through Tuesday:



The dark brown areas along the Wasatch spine indicate greater than 2″ of liquid.  It has a lot of potential!

The big disclaimer with this atmospheric river is the snow levels.  This moisture has warm origins and not a lot of cold air to work with. Snow levels should rise quickly after the start of the event and reach close to 7,500 feet during the day on Sunday… Perhaps rising even higher than that at times.  That means that some of the lower base elevations like Park City/Snowbasin/etc, could see rain at times.  The upper mountains and the Cottonwoods should be all snow, however it will be high density, wet cement.  Very good for base building, but not so good for skiing.  Make sure you wear gore-tex if you’re up there on Sunday or Monday.  The one other disclaimer is wind.  We are going to be near the jet stream, therefore high winds will accompany this event.  I’d expect northwesterly winds at ridge tops to gust up to 75mph during the event.

As for amounts, that is a tough call because the areas that will be favored will just see non-stop snowfall while other areas may only see occasional snowfall.  Also, with the high snow levels, the upper mountain will see much more snow than lower mountain elevations.  Overall, my initial estimate thru Tuesday is 18-26″ for the Cottonwoods, 8-12″ for Park City above 8k feet, and 18-30″ for the highest elevations north of I-84.  Again, I don’t expect this much at the base of most resorts, this is for the upper mountain where it will be all snow and better ratios.

Again, the skiing/riding could still be very good.  But this storm’s biggest benefit will be to drop a base and get more terrain open!

Tuesday – Wednesday morning: A break in the action as the AR retreats northward.  There still could be some lingering showers but nothing major.

Wednesday night – Christmas Day: The next storm moves into the area.  This system is colder and more progressive.  It should move through the region quickly but there is a good chance it brings snow to all elevations — with a decent powder day for the mountains!

Overall, it looks like the next 7 days will be a Christmas feast…


Long range:

Models are waffling a bit on what happens after Christmas.  The GFS gives us a break, the latest EC has another system dropping down from the north.  There is some suggestion that we undercut the ridge with the southern Jet by around New Years Day.  That would bring a very El Nino-like pattern to the west.  We’ll see…


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  • AZ

    Feeling pretty good this may be a white Christmas in the PC area!

  • Laura

    Does the arrival of the atmospheric river mean the ridge is finally breaking down and allowing the systems coming into CA to actually make it across the basin to Utah without splitting?

    • Not necessarily. The ridge is still there, it’s just centered off the California coast right now. It forces the jet stream and storms to ride up into the Pac NW then drop southeast into Utah. Compared to what the Wasatch, Cascades, and Northern Rockies are forecasted to receive, the Sierra are left pretty much unscathed, especially from Tahoe South to Mammoth.

  • Adam

    Does the southern Wasatch look to be included in this event, or will the atmospheric river be too far north? Hoping for some good base building down this way, too.

  • the videos and pictures you are embedding are cracking me up, LOL!

  • Tim Bowers

    12Z GFS moistens the Cottonwoods somewhat Sunday, leading to 1.5″ QPF, or 16-24″ by Monday morning, then drops off considerably Monday. But, the model also shortens the Christmas storm by delaying its onset by a few hours Thursday morning. Best bet again are in the Cottonwoods where 4-6″ are likely. Park City, etc, a mere 2-4″. After that, nothing significant from the 26th to Jan 4th except for a couple of passing waves on the Dec 29th and 31st where 1-2″ are all that’ll come out of them each.

  • Snow will fall above 8,000 feet all the way down to Central Utah, but the amounts will be significantly less south of SLC. Mountains south of Provo will probably stay under a foot.

  • DM

    We are due to fly into SLC from the east coast Thursday afternoon. Do you foresee a weather issue in the city affecting the airport with the colder system arriving then?

    • Christmas day… Theres a possibility but too early for details. SLC AIRPORT does great staying open during snow though.

  • Merry Christmas and thanks as always for being way beyond the news in your ability to forecast, explain and give a chuckle with the report. Much appreciated!

  • Charlie S

    Your forecasts are read every day and very much appreciated! Big thanks and Happy Christmas.

    On a more selfish note, I understand that predicting several weeks out is difficult but I hope to be visiting the Cottonwoods for a few days in mid-Jan – any chance for a repeat of this kind of snow event during the period 11 to 16 Jan?

  • PC Bump Ryder

    Love and need our tourists, but remember that our weather isn’t concerned with your vacation dates. Wet or dry, snow is what we need! Thanks Santa, looking like a VERY merry Christmas for all!