Summary

It’s hard to write a quick summary for this storm as it will have multiple parts and deliver a powder day to all mountains but on different days. The short, short story is that we’ll see heavy snow on Saturday night so most areas will see a powder day on Sunday, then the southern mountains will enjoy another powder day on Monday while areas east of the divide will be deep on Monday and Tuesday morning. The last part of this storm could bring another powder day on Wednesday to some mountains as well. Total accumulations will range from perhaps 12 inches on the low end to over 50 inches on the high end around Wolf Creek.

 

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Details

After 3 hours of researching all of the latest computer model forecasts, I am not going to make any big changes to the snow forecast. When I put out a forecast, especially ahead of a big storm, I triple check everything and try to keep my excitement in check so that we don’t collectively get our hopes up too much as it’s often tough to fulfill big expectations. I think my previous forecasts have summed up the storm pretty well and somewhat conservatively, and while I have written a full post below, you likely won’t find much new information.

The gist of the next few days is that we are going to see a powerful storm affect just about every mountain in Colorado and each area should have at least one good powder day, if not two or three.

The storm has already delivered snow to mountains west and north of Colorado, and this is heading in our direction. The map below shows the increase in snow-water equivalent from Friday morning through Saturday morning. Multiply by about 10-15 to estimate snowfall.

Source: Dr. Andrew Slater

 

Part 1 of this storm will bring a period of heavy snow to all areas of the state on Saturday and Saturday night. The heaviest snow will fall in the north (near Steamboat) on Saturday, then work south across the rest of the state late in the day on Saturday and Saturday night.

This band of heavy snow will be created by the combination of the jet stream at around 30,000 feet and a cold front near the ground. Ahead of the cold front, temperatures will be warm on Saturday, so the lowest elevations may see rain or at least mixed precipitation. Don’t worry too much about this as temperatures will cool and the precipitation will fall as snow when things really get cranking.

While Steamboat may see the powder begin to pile up late in the day (during opening hours), I think the best snow for all areas will fall at the tail end of daylight on Saturday and through Saturday night, ending by around Sunday morning. This should mean that all mountains will have a powder day on Sunday 1st chair, with amounts roughly in the 7-10 inch range. When the heaviest snow moves through, snowfall rates should be 1-2 inches per hour, so it won’t take long to pile up the flakes to respectable amounts. Also, some roads could close during the peak of Saturday night’s storm, so check CDOT for the latest.

Sunday and Sunday night should provide a lull in the snow for the northern and central mountains with just light accumulations, but the snow should continue to crank in the southern mountains thanks to part two of the storm moving in from the southwest.

This second act will arrive in the form of lots of moisture, winds from the southwest, and a strengthen storm spinning near the four corners of Colorado, Utah, Arizona, and New Mexico. Winds from the southwest favor Wolf Creek, Purgatory, and Silverton. And, even though a southwest wind does not favor Telluride, they should see the snow continue because the storm will be close to southwest Colorado and the lift created by the storm’s spin should somewhat counteract the negative southwest wind direction.

Further north, the central and northern mountains are not favored by a southwest wind, so I have kept amounts low on Sunday and Sunday night, just 1-3 or 2-4 inches. I do think that some areas in the central and northern mountains could see snow amounts that are higher than my forecast as most models show that the strengthening storm will provide enough lift to create a few areas of heavier snow that overwhelm the bad wind direction. That said, I have ZERO confidence about where these heavier areas of snow may set up, so I broad brushed the forecast with a few inches for all mountains and we’ll all just have to watch satellite, radar, and webcams to see how the snowfall sets up on Sunday, and which areas will bust the snow forecast and wind up much higher than my prediction.

Lastly, for areas east of the divide (Eldora, etc), the snow should begin to crank up late on Sunday night into Monday morning.

The scenario for Monday should be similar to Sunday with the heaviest snow falling in the southern mountains and east of the divide with a lull in the snow for most central and northern mountains.

Not much more to say about this. Monday in the southern mountains should be DEEP with snow falling continuously from Saturday night through the day on Monday. Also, east of the divide should be getting deeper during the day and will ski very nicely.

Here is the snow forecast map for Monday created by the high resolution CAIC model. If you notice nothing else, please take note about how complex the forecasting is for Colorado. There are many areas of the state which are forecasted to see 10+ inches while nearby locations receive almost nothing. Much of this is driven by the placement of the mountains and the wind direction, and since the mountains don’t move and the wind direction is often well forecast by the models, I have decent confidence about how the snowfall patterns will materialize. Most northern and central mountains are NOT favored by winds from the east, while easterly winds are good for areas east of the divide. In the south, the wind direction will be from the southwest, and this favors Wolf Creek and surrounding areas.

Source: CAIC

 

I wrote an update on Friday afternoon that I was a bit concerned that despite the unfavorable southwesterly winds, some central and northern mountains areas may still see good snow as the center of the storm moves directly across Colorado on Sunday into Monday. I am still concerned about this, but I can’t do anything about it. All I can say is that I have moderate confidence in the map above and the snow forecast numbers I create for each mountain, and that there could be some high-side surprises that I cannot forecast. I know it’s not feasible for everyone due to work and other commitments, but when there are big storms like this, I recommend trying to ski every day that you can even if the forecast isn’t that favorable - sometimes you’ll be surprised with better-than-expected conditions, but you’ll never know unless you go!

As the storm moves east of Colorado on Monday night into Tuesday, the winds will swing around to blow from the north and then the northwest.

A north and north-northwest wind direction in this pattern favors Powderhorn, Irwin, and Telluride to some extent, so watch out for these areas to deliver good snow on Tuesday. Then as the wind shifts from north-northwest to blow from the northwest on Tuesday afternoon and Tuesday night, watch out around Steamboat, Vail, Summit County, Irwin, and Telluride as there could be some high-side surprises for these areas. The models do not forecast these surprises (which of course is why they are surprises:-), but I’ve seen enough of them occur as storms pull away to the east to mention the possibility here.

Total precipitation from Saturday through next Wednesday will be impressive. Almost all mountains should see at least an inch of snow-water equivalent (about 15 inches of snow), and some areas could see 3+ inches, which would translate into 45+ inches.

Source: Weatherbell.com

 

The winner from this storm will likely be Wolf Creek. Since they will see moist winds from the southwest for ~48 hours, storms totals of 45+ inches are quite likely. The graphic below shows the forecast from many variations of the American GFS and Canadian models, and all are in remarkable agreement that Wolf Creek will see about 3.0 - 3.5 inches of liquid equivalent, or about 50-60 inches of snow.

Source: University of Utah

 

If you want the highest odds of experiencing the deepest snow, keep your eye on the southern mountains, areas east of the divide, and the western part of the central mountains around Irwin. Other areas will see good snow, but these locations will likely record the highest totals throughout the storm, almost assuredly more than 24 inches.

If you’re heading into the backcountry or side country, please keep in mind that big storms mean big changes in the snowpack. Do your research, communicate clearly within your group, have a plan B, and have fun!

That’s all I have as of Saturday morning … I will update on Saturday afternoon if I see any big changes in the forecast, otherwise enjoy the first part of this storm on Saturday night and I’ll be back on Sunday morning with my next full update!

JOEL GRATZ

 

PS - some of you may have noticed, via Facebook, that I am currently on my honeymoon, skiing at various locations on Hokkaido, the northern island of Japan. Lauren and I have been having a sensational time as this land has met and exceeded my expectations. I will be posting trip reports once I return in mid February. For now, here is a picture of deep, blower pow from Thursday. I have been looking forward to this type of day in Japan for years, even if the visibility was reduced at times by snow in the face:-)

Skier: Joel Gratz, Photo: Lauren Alweis

 

And here is Lauren, equally enjoying the bounty of Hokkaido’s plentiful pow (base depth is about 3 meters, or about 10 feet, and we received about 40 inches in three days).

Skier: Lauren Alweis, Photo: Nick Wilder

 

Lauren and I will be skiing and then sightseeing in Japan through February 13th. Thanks for allowing me the flexibility to work AND travel, and don’t worry as I am still spending many hours per day researching the weather for Colorado and will continue to post a new forecast each day. Here’s to powder in Colorado or wherever you happen to be!

 

Geography Key

Northern Mountains
Steamboat, Granby, Beaver Creek, Vail, Ski Cooper, Copper, Breckenridge, Keystone, Loveland, Abasin, Winter Park, Berthoud Pass, Eldora, Rocky Mountain National Park, Cameron Pass

Along the Divide
Loveland, Abasin, Winter Park, Berthoud Pass

East of the Divide
Eldora, Rocky Mountain National Park, Cameron Pass

Central Mountains
Aspen, Sunlight, Monarch, Crested Butte, Irwin, Powderhorn

Southern Mountains
Telluride, Silverton, Durango, Wolf Creek (Telluride and Silverton are on the northern side of the southern mountains)