Forecast:
Saturday (2/8): Snow ending with potentially sunny afternoon, highs in the upper 20s, westerly winds 20 mph with gusts to 40 mph.
Sunday (2/9): Increasing clouds with light snow, highs in the upper 20s, low winds (if you can believe it).
Forecast Discussion:
Punxsutawney Phil says winter is over, but the numerical weather models run by various governments and universities disagree. As inaccurate as the models can be, my bet is on the boring computers, not the cute groundhog.
Round one of snow this week is almost over – an upslope that dumped roughly 3” on the southern end of our patrol zone so far, with more likely on the northern end of our patrol zone. More analysis on this storm below. It’ll be very cold on Tuesday and Wednesday.
Round two of snow this week looks to be on Thursday / Friday with northwest winds. On the low end, the American Model is calling for 8” and the Canadian Model is calling for 9.5”. On the high end, the WRF Model is calling for 16” (through Friday midday) and the European Model is calling for 17”. There are a number of questions I have about this storm, from the impact of the jet stream to the strength of the spillover effect. If you want my guess as of now, I’d guess the American and Canadian model solutions are likely to be more accurate than the WRF and European Model solutions as I always put money on the effects of orographic lifting and precipitation shadows. I hope I’m wrong on this one. Regardless, as the storm is coming from the northwest / west, there should be more snow on the other side of the divide (Berthoud Pass could be a likely winner from this storm).
There may or may not be a round three on Sunday / Monday. American Model and European Model are calling for 0.5” starting late Sunday into Monday. The Canadian Model is calling for 5” on Sunday, and a second round Monday of and additional 4.5”. Let’s hope the Canadians are right.
Considering the weekend is sandwiched between the storms, I have low confidence in the weekend forecast. Also, I’m skeptical of the forecast of the low wind forecast on Sunday simply because low winds are a rarity in our patrol zone. That said, both the American and Canadian models are calling for winds of 10 mph or less on Sunday.
Looking back, we got skunked in this last upslope storm. I measured 5.5” at my house at 6,000’ in Golden. Eldora reported 3”, which looks consistent with their snow stake camera, and which is about the same as what Loveland and Winter Park reported. (Hopefully a bit more snow will fall today.) So, how did the various models do? The European Model called the storm the closest to accurate the day before the storm began (4”). At the start of the storm, the NAM model called the storm the most accurately (3” morning of, but predicted 5” one day out). American Model, HRRR, and WRF Models were way off the mark (6” or more predicted).
Looking back a bit further to this past weekend, past Sunday was sunny and warm on Guinn Mountain and Bryan Mountain (a crazy 45 degrees at 10,400’ at Eldora at 2 pm), but happily much less windy than predicted. I wasn’t in the mountains on Saturday, but it looks like it was cloudier than forecasted.
Looking ahead, next week looks to be a snowy one as well. Yeah! Although out in forecast fairyland, the American Model and the European Model are predicting 4” and the Canadian Model predicts 6.5” between next Monday and Thursday.
-Jordan (Tuesday morning)
Note: Unless otherwise noted, all forecasts are for 10,000’ in exposed areas. References to American Model are the American (GFS) Model. References to the Canadian Model are the Canadian (GDPS) Model. References to the WRF Model are the CAIC WRF Hi-Res Model. References to the European Model are the European (ECMWF) Model.
