The atmosphere is once again going to drop some spring goodness on the Wasatch, just in time for Alta's (2nd) closing weekend. Don't be expecting the incredible dry powder skiing we had with the last storm 10 days ago though...with such a warm storm this snow will be of the more dense variety, not as much snow will fall, and snow levels will be rather high at times (staying at or above the benches even during the coolest periods of the storm). Nevertheless, this multi-part storm will be with us for the entire weekend, and it should have plenty of moisture and dynamics to work with. So we could see some decent powder skiing.
The first wave of precipitation arrives with a shortwave trough tonight, and then a second, colder and stronger trough will bring another round of snow Saturday night into Sunday morning. These will be the periods of heaviest precipitation, but showers will likely continue in the intervening periods. I'm going to go with 9-18" for the Upper Cottonwoods. The snow density will be highest with tonight's wave (not quite Sierra Cement density though), and then the powder will be a bit drier Saturday night/Sunday.
Sunday morning will be the best time to ski. Accumulations will be near their peak, and the temperatures begin to warm through the day.
After Sunday, we warm up and dry out. It looks like the Bird will stay open a few more weeks, but we at USW will be hanging up our forecasting hats this Sunday. In the meantime, enjoy the snow this weekend!
In short, a succession of weak trough will cross Utah between tomorrow and Sunday. There will be just enough moisture with these troughs to set off light showers over the mountains each day. Accumulations should be minimal until Friday afternoon into Saturday, when there is potential for enough snow to actually improve the riding conditions.
The snow quality might not be too bad Saturday either, as the current GFS run brings the freezing level down to around 6000 or 7000 feet. Not bad for late April. The ECMWF ensemble is also in agreement with the GFS on the possibility of a mini powder day. Lets keep our fingers crossed.
Well, with only Little Cottonwood remaining open (and Alta really only for another weekend), there's not going to be much of an audience on here, I'm sure. Nevertheless, I will soldier on and attempt to give reasonable guidance for the next week or so...
It's sort of an odd week upcoming in the models. The GFS shows some underwhelming and weakly forced systems plodding through the state as a low drags to our south and then a mild trough follows. The best precipitation looks to be associated with the latter event, as it chugs through Friday night and into Saturday. Prior to that, scattered showers associated with the mostly-cutoff low may impact the area on Wednesday and Thursday, but most of that period should just have cloudy skies and mild temperatures. Regardless, if things stay as expected, the best skiing should be on Saturday in the post-frontal environment, although Friday during the day MAY be decent as well.
Well the resorts are starting to close up, this Sunday is Alta's closing celebration. It will close for the coming week and reopen for April 25th and 26th, and there may be some more snow that weekend, but that's a little far out to forecast. For the festivities this weekend, however, most would prefer some warm sun and corn snow, which up until the recent storm seemed all but guaranteed.
Now that chance seems to be up in the air, with other forecasting websites and the NWS suggesting a chance of storms and cloud cover. I'll use this forecast to talk about why we'll still see the sun on Sunday at Alta. The GFS is showing instability developing at ridge top levels over the weekend. This is due to advection of cold air from the North running over relatively warmer air lower down. This should encourage turbulence and gusty winds. However, without a significant source of moisture, this instability cannot do more than create a few scattered clouds. Some of those clouds may grow large enough to produce some light snow over small regions for short amounts of time. More likely they will produce precipitation that evaporates, causing cold downdrafts which will be eperienced as strong gusts of wind by skiers.
So all in all we don't expect clear blue skies but still plenty of chances to see the sun between beautiful scattered cumulus clouds. It may get windy and cold for a moment under a cloud, but then it will be back to the sunshine.
Well, my forecast back on Monday of 8-16" in the Upper Cottonwoods busted pretty badly, but I'm not too upset about it because it busted on the low side. Moist northwestery flow following Tuesday's cold front, and some likely periods of lake-enhancment (especially at Snowbird), produced some Cottonwoods Magic yesterday. We haven't seen any of this magic since January, so it was really nice to see a storm go crazy over the upper canyon and produce way more snow than anticipated.
The snowfall totals through this morning include 44" at Snowbird, 32" at Alta-Collins, 22" at Brighton, and 7" at PCMR. To add to the awesomeness, the cold atmospheric temperatures kept the water content of the snow quite low, so the "Greatest Snow on Earth" was back in Utah yesterday. Jeff, Trey, and I skied at Snowbird yesterday, and the conditions were incredible...some of the deepest snow I've skied there from a 1-day storm.
Anyway, this is a forecasting website, so some of you probably want to know when/if it's going to snow again! That's a good question. Occasional snow showers will continue in the mountains through tonight, and then skies look to clear somewhat for Friday and Saturday...although the storm to our east will continue to affect us with some clouds. Temps will be much warmer though, so go get the fresh snow today before the April sun puts a crust on it. I mean it...the snow will not be light and fluffy for long with the high sun angle this time of year. Sunday it looks like a weak shortwave will move through, bringing some showers to the mountains, and beyond that we will warm up and dry out.
So enjoy the brief return to winter while you can!