Let it snow, let it snow, let it snow ...
Heavy snow is hitting the mountains and has been since Thursday afternoon. Upwards of a foot has already fallen on some areas like Copper, Loveland, and Winter Park Ski areas. Those areas are bracing for another 1-2' of snow before things wind down on Monday morning.
There's a lot to update here so scroll to what you find interesting—first, Avalanche Danger, then mountain snow update, and finally, Denver snow update.
Avalanches, according to the CAIC, will be easy to trigger by humans. This is a very big concern as more snow is likely to accumulate and avalanche dangers will be ever-increasing. Even small avalanches can harm or kill someone, so please take this seriously this weekend. We have already seen one avalanche death this season.
This is very important information. Backcountry avalanches area LIKELY this weekend with avalanche concerns increasing as more snow accumulates. Please, be cautious out there this weekend. @COAvalancheInfo pic.twitter.com/cnfZAuP4EG— Andy Stein (@AndySteinWx) December 13, 2019
SNOW TO COME FOR THE MOUNTAINS:
First, where the snow has already fallen.
So far the snow has fallen mainly in the central and northern mountains. Where you see yellow and orange, that's where 6"+ of snow has already fallen. There have been numerous reports of a foot of snow already falling up there! This is going to be a great ski weekend, but not a great travel weekend, at all. Travel will be near-to-impossible at times. Please plan an alternate route or be sure to take your time and have appropriate snow gear and car snow gear handy.
The mountains are benefiting from what is called an atmospheric river. Basically, a plume of moisture originating from Hawaii is pumping in a lot of Pacific moisture into the state. We don't typically see atmospheric rivers produce this much moisture for Colorado. It's not unprecedented, but it's abnormal for sure. With that said, there will be a lot more snow to come and a lot of wind that will accompany that.
I love it when weather becomes obvious. The "Pineapple Express" is bringing tropical moisture to most of the Western US and it's very clearly originating from a place with a lot of pineapples. #PineappleExpress #WinterStorm #Satellite #GOESWest pic.twitter.com/KaaE0O6Ytc— Andy Stein (@AndySteinWx) December 12, 2019
Additional snow to come with be upwards of 12-18" for a lot of mountain folks—especially above 9,000'. There will be reports of storm totals of over 3 feet, but where that occurs depends on where the heaviest snow bands set up. Either way, traffic will be miserable, snow will be heavy, the wind will be extremely strong and this will last for the next 3 days.
Winds will be peaking at about 80 mph at the highest elevations but more commonly, 40-80 mph winds will be felt. Those winds will even make it down into Denver.
Denver hasn't seen much snow since our big Thanksgiving snowstorm—and there are still piles of snow to confirm that. The snow that is coming for Denver is going to be fickle. The storm track and storm intensity for the snow this weekend has not been consistent. So, what I do know is that most of the models have been suggesting that this storm will be bigger for those South of Denver. Monument, Colorado Springs, Pueblo—you guys will likely see more snow than Denver, but if the track of this system starts to meander a little bit more north, we could see more snow in Denver.
The EURO model has been the best this winter with handling snow, so I'm showing what the latest run of the ECMWF has spit out for Denver and the snow totals are up! But I'm not buying it just yet.
Again, we will have to account for where the storm comes in at and how much moisture it brings along with it, and how much wind it brings as well. We'd like to get the Upslope wind a little stronger so we increase our snow totals.
I'm thinking that right now we're looking at 1-4" across the Metro will higher amounts to the south and to the west of town.
It will also get very cold in Denver this weekend.
This isn't frigid, or even record-breaking, but it's going to be much colder than the previous few days.
Enjoy the wild weekend weather, and keep looking for updates!