Since my last post, the models have given us a number of solutions for the upcoming winter storm. The trend continues to be edging this system west which would result in more favorable chances for snow and rain for SW Colorado.
Since I started tracking this storm I have said that the positioning of the closed area of low pressure will determine our fate. The latest model runs clearly demonstrate that.
Timing is another important factor. A later arrival to our forecast area would boost the chances of snow in the lower elevations. That is what is starting to happen, the models are starting to slow the arrival. This is normal, the models early on are almost always too fast with a storm’s arrival.
Here is the current position of the wave (circled in red) that will form into the storm.
The high to the north of the wave is the leading edge of the arctic air. Overnight tonight it will start moving south and dragging the system into the United States.
Here is what that looks like between noon today and noon on Monday
Monday afternoon the storm moves into Wyoming then into Colorado early Tuesday morning.
Noon Monday until 6 am Tuesday
Finally, the storm moves deeper into Colorado Tuesday throughout the day and night.
Tuesday 6 am to Wednesday 6 am
After that, the models diverge with the Euro and Canadian keeping numerous showers and snow going until late Thursday and the GFS wrapping up late Wednesday.
Here are the last two runs of the GFS snow forecast
Overnight GFS run
Latest GFS run
The last two runs of the Canadian have been pretty crazy, to say the least. The Canadian has shown the closed low in a very favorable position to draw in subtropical moisture from the south and wrap-around moisture from the east. The big story here is the liquid precipitation totals.
Saturday night’s Canadian run showing significant snow in our higher elevation areas
Here is what it showed for liquid precipitation
Here is the latest Canadian run for snowfall
Here is the liquid-equivalent precipitation
Crazy?? Yes, probably. But I am not sharing these Canadian runs with you because I think it is going to happen. I am sharing these to illustrate that the models are evolving and are not in agreement yet at all.
Moving on to last night’s Euro
Here is the liquid-equivalent
Here is the latest run from the Euro, it has a similar set up to the Canadian showing 3 feet at Wolf Creek!
Here is the liquid-equivalent
I talked a little bit about temps yesterday. Unfortunately, there is very little agreement on what to expect and a couple of degrees can make a big difference. I think most areas above 8,000 feet will see freezing temperatures on Wednesday and Thursday morning. Between 7,000 and 8,000 feet it will be very close. Future model runs will hopefully give us more insight. If the storm moves out quickly and things clear out quickly it could set the stage for freezing temps in the lower elevations. However, if the Canadian and Euro are correct the closed low will be bringing in a lot of moisture and it will be too cloudy to freeze in the lower elevations.
If the Euro or Canadian verify the situation is going to be a much bigger event than most people, including the NWS are expecting. I will be anxious to see all of the updated model runs tomorrow morning! If the Euro and Canadian run continue with this trend we will see big changes to the forecast and several very strongly worded Winter Storm Watches and Warnings and probably some flood statements as well.
This situation is evolving rapidly so stay tuned.
On Monday I will do a morning and late afternoon storm update. Thanks for following and supporting the page!