Snow-ho-ho (Saturday PM update)

Saturday, December 22, 2012 at 7:21 am

Saturday, 4 PM update:

As always, things are becoming increasingly clear with regards to the upcoming storm. Everything still on track for us to be grazed by a system tonight and early tomorrow morning. 1-4″ of snow likely in the high Wasatch by tomorrow AM, mainly north of I-80. Stronger system moves into the area late Sunday night and snow will continue through the day on Monday. NWS has already hoisted a Winter Storm Warning for the Southern half of the Wasatch with a Winter Weather Advisory for the northern half. It’s looking like the best snow will fall from about I-80 south to about Beaver, UT. Above 7,000 ft in these areas, 10-18″ of snow will be possible by late Monday night. This includes the Cottonwoods and Provo Canyon. Park City ridge will see slightly less with 8-14″ at these ski resorts. Farther north, Snowbasin, PowMow, and Wolf Mountain might again see the short end of the stick, but I still expect 6-12″ to fall there. Lower valleys still look good to see 1-3″ on Monday that should provide most with a white Christmas. Another system still in the cards for Wednesday-Friday but details are still a bit sketchy.

Full update in the AM.

Saturday update:

Systems continue to push into the west coast as the large parent low spins off the Pac NW coastline. Everything still on track with previous forecast. Main change is that short-range models are now within range and bringing in the details, so we have greater confidence in snowfall amounts. We will have breezy conditions today with a warm southwesterly flow ahead of the approaching systems. This flow should scour out the cold pools (inversions) in the valleys and allow them to warm up. Clouds should also be on the increase this afternoon.

Tonight we have the first weak wave bring mostly mountain snow showers after about midnight. This will primarily affect the mountains north of I-80 and could bring 1-3″ of fresh snow for tomorrow. We will then see a break in the action Sunday afternoon / evening as the next, more potent, system enters the area.

This stronger system will bring snow to the area late Sunday night and the snow should continue all day on Monday before tapering off on Monday night. The system is currently progged to track perfectly to bring the entire Wasatch a good period of both frontal and post-frontal snowfall. This is by no means a major snowfall for the Wasatch, but everything looks good for a decent period of snow. The lower valleys might start as rain or rain/snow mix early Monday morning before changing to all snow as the front approaches late Monday morning. Valleys can expect 1-4″ of snow. The Wasatch should see .75-1.25″ of QPF and average snow ratios of 15:1 — this translates to about 10-18″ of snow for the high elevations. Not too shabby! Monday will be a great storm day powder day with more fresh snow on every run!

Here is the latest model-generated snowfall forecast for the Western CONUS through Christmas day:

Snowfall forecast

We should clear out on Christmas Day for blue bird conditions. Wednesday we’ll see the next system approach with snow likely Wednesday night-Thursday night, perhaps lasting to Friday. At this time this looks like a moderate storm. Great news for all the holiday skiers who are traveling to Utah for some freshies. But it could cause some travel headaches.

The Cottonwoods and PC continue to do alright this year and are just above average snowpack, but the Northern Wasatch is struggling at less than 50% of normal in places so lets hope we can get some good snows going in their direction as well.

Let it snow! WSF


Friday PM update:

Everything still looking good in the discussion below . . . 1-4″ on early Sunday morning and 6-12+” on Monday for the Wasatch. Valleys will have a good chance at a few inches of snow on Christmas eve as well. Next update tomorrow AM . . .

Today’s forecast is on the assumption that the Mayans simply grew tired of writing their calendar and not that it’s the end of the world. So assuming that we all wake up tomorrow, here’s what we can expect:

The much talked about Eastern Pacific low pressure system is now establishing itself off the coast of the Pacific Northwest where it will park itself for the next 48+ hours. There are three distinct waves that will move into Northern California:

1) The first is moving through right now and will weaken and eject north of Utah tonight, essentially doing nothing for us.

2) The second impulse moves onto the coast early tomorrow morning and will reach Utah by late Saturday night. This too will weaken considerably and mostly miss us to the north, but should be good for some snow showers on Sunday morning. Expect only a few inches accumulation early Sunday morning in the high elevations.

3)The third and final impulse is the most potent and will hold together the best as it moves across the Great Basin as the broad trough progresses inland with it. This system should bring snow to the mountains and rain/snow to the valleys by very early Monday morning and should continue during the day Monday before tapering off Monday night. Snow levels will drop on Monday to all valley floors in Northern Utah, so everybody should at least have a shot at a white Christmas. Right now, accumulations look to range from 6-12″ in the high Wasatch with up to 16 inches in the Cottonwoods and other favored areas . . . 1-4″ in the Valleys. This is an early estimate and will likely need to be fine tuned this weekend.

Here is a map showing model predicted snowfall over an 84-hour (3.5 days) period beginning yesterday evening:


These maps aren’t very accurate this far out, but in Utah, you can generally see what areas are likely to see some snowfall on Sunday and Monday. You can also see the Sierra Nevada to our west getting clobbered. The scale only shows up to 4 feet of snow but the Sierras are literally off the charts and should have places that exceed 75″ of snow during this time frame.

As mentioned yesterday, Monday should be a storm powder day with snow falling steadily. We should start to clear out on Christmas day and could have blue bird powder conditions on our hands. Another system will approach the area on Wednesday and we will start to have a chance for snow again. Both the GFS and the Euro split this system well to our west. The GFS drops the split low into SoCal before ejecting it northeast right over Northern Utah. The EC, however, keeps the low farther south and tracks it over Southern Utah/N. Arizona. This would mean much less snow for the Wasatch. We’ll have to monitor this system over the next few days but right now it’s safe to say we’ll have a chance for more snow for late Wednesday through Friday.


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