Last post for a bit. A look at the active patten shaping up for end of December

12/20/24 8:45pm: Hi, one last post before we leave to Costa Rica and Thomas Horner takes over (he usually brings in some crazier weather and the knowledge to go with it ). Anyway happy official start to astronomical winter!...the winter solstice is Sat at 2:21 am MST. Certainly doesn't feel like winter now...but it eventually will by next week.

As I mentioned a few days ago (and the trend is holding) the pattern is slowly going to get more active and colder starting Sun/Mon....then all eyes on the next two storms systems Wed/Thu and Fri to Sun (12/27-12/29), those storms could be stronger with good snowfall. It now looks like much of the mountains will have some snow on Christmas with a small chance for Den/Bou but likely not much (mountain folks white Christmas is likely)

Here is a look at what I'm seeing in the forecast:

First wave: 11pm Sun to 5am Tue (12/22-12/23):

• 2-6” for north-central mountains / local ski areas.

• Just wind for Den/Bou, Palmer Divide may get a little bit of snow Tue night

  
  

Next stronger storm system from 5am Wed to 5am Thu (12/25-12/26).

• This one is interesting as models show a closed low tracking across CO…right now looks to be too far north for much upslope / snow for Den/Bou but if it tracks south could bring some snow.

• Additional 2-6” expected for the local ski areas / I-70 mountain corridor likely

  
  

Third storm expected: 5am Fri through 8am Sun (12/27-12/29, two waves in the larger storm, colder air with this one).

• This looks like a more prolonged, cold snow event favoring the north-central mountains, could be 4-10”+ additional for ski areas but uncertainty is high

• Den/Bou could get some snow Fri night into Sat or maybe even Sat into Sun (amounts uncertain), will be much colder after 12/28.

  
  

Looking a ways out, models continue to show an active and cold pattern especially from around Mon 12/30 through Fri 01/03/25…details still need to be worked out for that time period but looking good for more snow and pow skiing ... I’ll be back for that

Anyway, off early tomorrow morning. We are heading to the more wild-side of Costa Rica, southeast coast, the jungle / animal coast, going to Puerto Viejo where Miriam and I went 8 years ago (but this time with all our family, sisters family and Mom and partner). Going to be fun, of course I’m tracking the weather down there..it can rain a lot at times but very warm (temps between 75-85 the entire time). You can think of me if it snows in CO.

Happy Holidays everyone, enjoy your time! Thanks for filling in Thomas Horner

First image shows forecast total snowfall from now through 5am next Fri 12/27, for the first 2 waves, but take with a huge grain of salt since its a week out and details will change. Second image shows total snow through 11am Thu 12/26 from latest ECMWF so only a few of the waves. Third image loop shows the evolution of the pattern via 500mb vorticity / wind over the next 15 days from latest GFS..you can see it get much more active as we head towards January (Static image shows the pattern at 11am Wed 12/25.

Cheers!