After a long stretch of having to use my A/C at night the past few weeks (overnight lows were typically what we would see in July!), it FINALLY feels like fall in the Wasatch this morning. An upper-level trough dropped into Utah last night, and brought some much needed rain and even snow above about 10,500ft in the Wasatch.
So after a glorious summer of river trips, trail running, mountain biking, and climbing, it's about time for us here at Utah Ski Weather to start shaking the cobwebs off our snow forecasting skills and prepare for the ski season! We...well at least most of us...have made good progress over the summer on our thesis and dissertation research here at the Atmospheric Sciences Department at the U, so we are once again recharged and ready for another season of bringing you all high quality snow forecasts for the Wasatch!
That being said, you may be wondering, "will we finally have a normal or above-normal winter?" It's been 4 very long years since this happened.
Well as you may have heard, it's a virtual certainty that El Niño conditions will be present this winter, and confidence is increasing that it will be a strong El Niño. So what does this mean for Northern Utah? Unfortunately not very much. Strong El Niño years typically mean a high chance of a wet winter in the Southwestern U.S. and a high chance of a dry winter in the Pacific Northwest, but Northern Utah is of course in neither of those regions. Southern Utah (I'm looking at you, Brian Head) looks like they have a decent shot at a good winter though. If you take a look at the NWS Climate Prediction Center's 3-month precipitation forecast, you'll see that they made their forecast based primarily on the forcing from El Niño (there are many other oscillations that affect global weather patterns), and that the Wasatch is indeed in the region between high chances of above normal and high chances of below normal. Fight the temptation to conclude that that means we'll have an average winter...it just means that there is no predictability this winter for Utah. It's a total crap-shoot. I know I know, many of you are probably thinking "a meteorologist just told me that there's a 50-50 chance we'll have a good winter, that's really helpful." Well while 7-day weather prediction has become quite skilled in the modern times of super computers and satellites, the truth is that season-scale climate prediction is still in its infancy. So you can always take a look at the absolute garbage that is spewed from non-scientific sources like the Farmer's Almanac, but I prefer to do a snow dance, pay attention to the forecast each weak, and make my ski plans accordingly!
We'll be keeping an eye on the weather from here on out, and as soon as it looks likely that our first big, skiable Fall storm is on the horizon, we will be sure to let you know. We look forward to a great season and thank you for checking out USW!
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.