It has been a good week for the mountains for sure. There were a few smaller storms and a few bigger ones, and the holiday weekend has seen mostly fair weather with some showers adding a few inches to the total. Alta-Collins has made it up to whopping 134″ of depth. That’s 11 feet and 2 inches or 3.4 meters.
For a while now we’ve been able to see a big storm on the horizon to look forward to. Right now that isn’t the case. There are hints of something next Monday, but that’s far away and doesn’t seem all that impressive. But it’s not like we’re having an early spring. The weather pattern we’re getting into is characterized by persistent troughing. The atmosphere can be thought of as a composition of a lot of waves. Some of these waves move quickly around the Earth, others move slow as molasses, and others even go backwards. The fun weather tends to happen at the transition points between troughs and ridges of the larger waves. Have a look at how the waves will be tomorrow:
This is a representation of the waves in the atmosphere halfway up (and green shading for humidity). Notice that Utah is right in the middle of a large and deep trough. The winds are weak and the jet stream is well to our south. Troughs can be like ridges in that they can be a bit stagnant. However, they are significantly better than ridges for winter enthusiast for a few reasons. First is that we’re north of the jet stream and it’s cold. Second is that there’s a lot more (relative) humidity around. Third is that cold air above 40°N land in late February can be a recipe for popcorn showers.
These ingredients together mean that I think it’s going to be a good week. It’ll give the snowpack a chance to settle, and the clouds will keep that late February sun at bay (it’s as strong today as it is October 24th). Plus we’ll have weak showers that keep thing fresh all week long. Below is an ensemble forecast for the Cottonwoods, and it shows how we’ll get an inch or two several times this week just from pop-up showers and weak disturbances (the CMC members in this case is out to lunch and should be ignored). One of the troughs we’re under is one of the really slow ones, so it’ll be a while until we’re back into a super stormy pattern. But I’ll take this over a ridge any day.