Quick update, Tuesday, December 27 8:30 PM:
Not too much new to talk about, models have SLC on the southern fringes of the storm track with the vast majority of precipitation falling to our north. Jackson Hole should receive 1-2 feet of snow over the next few days so a road trip up there might be the way to go if you are dying for some powder. Impulse will move through Wednesday afternoon/night with chance for rain showers in the Salt Lake valley and light snow in the mountains with only a couple inches, mostly north of I-80. Another impulse for Friday could add another couple inches in the same locations. Basically does nothing for our snowpack unless jet digs dramatically farther south than it’s current forecast.
Long range shows ridging building in next week for at least a few days, perhaps changes could be in store for the end of next week as 12z GFS looked very encouraging but 18z quickly backed off on that idea. Still hoping for troughing to develop around the 8th of January or just beyond. Will have to wait and see.
Hope everyone had a lovely holiday! Now that you’ve spent the obligatory family time, it’s time to turn your attention back to more important things, like the ski forecast. So here we go . . .
You may recall that in my last full post, I made a prediction that we may transition to a wet pattern during the second week of January. I made that prediction based on large-scale climo factors like the AO and PNA. Today things are looking better for that to verify, as the MJO is now forecasted to start moving again into latter phases which are more favorable for west coast troughing. Also, the models are starting to hint at troughing developing sometime around January 8.
This week we will have a strong zonal flow (relatively flat, fast jet stream) that will take dead aim at the Pacific NW. Waves will move on-shore approximately every 24 hours. Our first wave brushed the area last night but did little except slightly moisten and cool the upper atmosphere. The next couple waves will do very little with just slight chances for rain/snow showers near the Idaho border. The first decent chance for precip for the Wasatch adjacent to SLC will come on Wednesday and Wednesday night. However, even then we expect rain showers in lower elevations and only a few inches of snow in the mountains at best. This chance for off-and-on showers will continue into about Saturday before ridging clears us out. The main message for this week is that at the very least, this pattern should clear out inversions and warm up valleys. The farther north you go, the more likely you are to receive precipitation. This graphic illustrates expected precip for the next five days (12/26-12/30) and shows how quickly it drys out as you get south of the Idaho border.
Beyond Saturday, we see a ridge build in for at least a few days but it’s starting to look like as we head toward the first full weekend of the New Year (Jan 7-8) we may see a large scale trough develop as the ridge retrogrades into the Pacific. We’ll have to wait and see.
Stay tuned . . .