Wasatch Weather Weenies

The Cottonwoods have always been popular, but this winter, things are completely out of control.  This was the scene at 10:15 AM at Solitude.  The lower lot was full.  Cars were parking up and down the road, and chaos ruled. Another perspective, showing cars parked along the road presumably to the upper lot. As Yogi Berra said, "Nobody goes there anymore, it's too crowded."  Traffic and red snakes aren't new to the Wasatch.  What is new is that this is happening every weekend.  The status quo has to change. Fortunately, although the backcountry is busier than it used to be, the views haven't changed and remain spectacular. And the snow is still the greatest on earth.  FM-100 Easy Listening Turns today.  Right-side up and smooth as silk.

After heavy upper-elevation snowfall last night, mid elevation rain, and more snow expected today, we spent the afternoon "cowering in the aspens", avoiding avalanche terrain, and wondering why it wasn't snowing harder. From yesterday afternoon to 5 PM this afternoon, Alta ended up with a total of 1.57" of water and 13" of snow, which I have to say is disappointing after looking at the radar this morning (see previous post).  After 7 am, storm totals were only .47" water and 6 inches of snow.  I thought we'd see something closer to 9-12 based on the morning radar. Backcountry ski conditions ranged for very good to "pinbally".  Conditions were very good up high where the bottom was smooth.  Down low, in areas where there was overnight rain on snow (or at least a melt freeze cycle), we did a lot of bouncing off of old tracks.  Higher snowfall rates would have helped, but freshies are freshies.

From late yesterday afternoon until 7 AM this morning, Alta-Collins has observed 1.09" of water equivalent and Snowbasin Middle Bowl 1.15".  Ben Lomond Peak is around 1.4". Temperatures at Alta-Collins (9662 ft) peaked at 32ºF from 11PM to midnight, afterwhich they lowered gradually and then more abruptly with the passage of the cold front early this morning. At the base of Alta (8560 ft), and at Snowbasin Middle Bowl (7402 ft) it reached 37º.  Thus, rain may have mixed in with snow as high as the lower slopes of Alta and Snowbird and mid mountain Snowbasin during the warmest part of the storm around midnight.  Temperatures have since fallen and the recent passage of the cold front has lowered snow levels to the valley floor. At upper elevations, the 1.09" of water at Alta-Collins yielded a total of 6" of snow, yielding a water content of 18%.  Serious Sierra Cement.  However, the snow falling this morning and today should be drier. The radar loop is...

Sometimes I come in an my job is easy.  The satellite image below pretty much tells the tail  tale (!) and if it doesn't cause your heart rate to pick up just a bit, you are reading the wrong blog. IR satellite imagery from 0600–1400 UTC 29 Jan 2016 Yup, we are in the cross hairs of a potent atmospheric river that is pushing into northern Nevada this morning.  Model forecasts for tonight and tomorrow have been remarkably consistent over the past day or two and continue to bring the atmospheric river directly over northern Utah by 0600 UTC 30 Jan (2300 MST tonight). GFS integrated water vapor transport forecast valid 0600 UTC 30 January 2016. Source: NWS. The integrated water vapor transport associated with this atmospheric river is quite high for late January and lies at the outer edge or outside values observed in the climate forecast system reanalysis for this time of year.   Source: NWS Bottom line #1 : This is an unusual event for this time of y...

Update @ 12:20 PM:  Post has been updated with corrections to NAM precipitation rates and Alta 24-h precipitation climatology.   We could talk about the inversion and air pollution that are currently blocking our views and clogging our lungs over the Salt Lake Valley, but it's more fun to think about the storms and snow that are coming our way Friday and Saturday. There are two major players in the Friday–Saturday storm.  The first major player is a potent atmospheric river, or corridor of high integrated water vapor concentrations (a.k.a. precipitable water, color contours below) and integrated water vapor flux that is presently over the eastern Pacific. This atmospheric river is expected to push into the interior western United States on Friday.  The GFS precipitable water forecast for 0000 UTC 30 January (5 PM MST Friday) shows the corridor of high precipitable water oriented nearly perpendicular to the northern Sierra.  Although water vapor depletio...

Smoggy air is worsening as inversion conditions have developed over the Salt Lake Valley and Wasatch Front. Soundings collected Monday, Tuesday, and this (Wednesday) morning show the development of the inversion quite nicely.  Note in particular how temperatures have warmed aloft, especially in the layer from 800-600 mb (about 6500 to 13000 feet).   Source: University of Wyoming This is fairly typical for the development of an inversion in the Salt Lake Valley during winter as temperatures warm dramatically aloft, but remain relatively steady or cool just slightly near the surface.   Note, however, the wind directions in the soundings above.  Above the surface, they are predominantly from the NW, N, or NE.  Where is all this warm air coming from if the flow is from the northern part of the compass?   Well, the assumption that flow from those directions is transporting colder air from the north is often a poor one when a ridge is loc...

After 7-10 days of active weather, the Wasatch are enjoying a brief lull this week with high pressure in control through Thursday. Looking further out, however, it appears we will have a return to stormy weather possibly as early as Friday and likely by Friday night or early Saturday. The origins of the storm can be traced to the western Pacific.  While you were skiing deep powder last weekend, a developing cyclone was extracting a slug of high precipitable water (and hence water vapor content) air from the tropical western Pacific.  Subsequently, a potent atmospheric river formed and has been maintained along the trailing cold front accompanying the cyclone and is expected to reach the west coast of the U.S. later this week.   Observed satellite imagery and GFS analyses and forecasts of precipitable water (warm contours) and simulated clouds from 1200 UTC 24 Jan to 0600 UTC 29 Jan 2016. The GFS integrated water vapor transport forecast for 0600 UTC Saturday (2...

It's egotistical and narcissistic, but a few years ago I coined the phrase "Steenburgh Winter" to describe that period in the central Wasatch from the first day Alta-Collins reaches a 100-inch base until February 10th.  Steenburgh Winter is meant to highlight the creme-de-la-creme of backcountry ski conditions, which occurs when there is both a deep snowpack and a low sun angle. The 100-inch barrier is a good mark of when we have a robust mid-season snowpack.  There is of course good skiing at lesser amounts.  Yesterday, for example, offered up some fine backcountry skiing, but there are some areas in the Wasatch, especially in the rock-strewn Lone Peak Wilderness area, where deeper snow cover is a necessity. February 10th was recommended to me by a good friend in the avalanche business as the day when one really starts to notice the impact of the sun on the Wasatch snowpack.  Prior to February 10th, one will occasionally find melt-freeze crusts produced by the s...

It's been a pretty good storm so far in the Cottonwoods.  Alta had 11" through 8 am, close to the upper threshold of the 6-12" I forecast yesterday, with snow showers at times continuing today.  We also hit 80" total snow depth at the Alta-Collins stake, a nice psyche point, although we'll probably retreat below that again with settlement. It's rare that those in New York, Philadelphia, and Washington D.C. can look down their noses at Wasatch snowfall, but in terms of amount, they can do it today.  As reported by weather.com , here are some selected peak snowfall totals by state through early Sunday morning: 40": Glengary, WV 39" Philomont, VA 38" Redhouse, MD 35.5" Somerset, PA 30.5" JFK Airport, NY 29.6" Whitehouse, NJ The snow was high density and many areas also had strong winds.  The graphs below are for Kennedy International Airport (JFK) and show the snow-depth (measured every 6 hours) increasing from 1 inch a...

I awoke this morning to a beautiful mountain wave cloud that was draped over the Traverse Range at the southern end of the Salt Lake Valley. Mountain waves form during flow across topographic obstacles.  The Traverse Range has a maximum elevation a bit over 6500 feet, and a deep gap where it is bisected by the Jordan River, but is plenty high enough to generate such waves despite being small compared to the surrounding Wasatch and Oquirrh Mountains.  One often sees mountain wave clouds over the Traverse Range (and typically Lone Peak as well) in advance of approaching storms, so whenever I see one, I take a peak at the latest computer models. Indeed we have a trough approaching northern Utah this morning and expected to move across the area tonight, bringing precipitation to all elevations. Mountain snow and valley rain will begin late today, with precipitation changing to snow at all elevations overnight.  For the mountains, this is looking like a pretty good...

Although it's going to be a beautiful bluebird day, I'm working and there's three topics to discuss this Thursday. 1. 2015 Was Utah's Third Warmest As noted in the previous post, 2015 was easily the warmest year on record globally, and by a wide margin.  For Utah, 2015 comes in as the 3rd warmest on record, behind 1934 and 2012.  It also extends our run of years at or above the 20th century average temperature to 22.  The last year cooler than the 20th century average temperature was 1993, with 2011 right on the average. Source: NCEI With regards to temperature, two highlights stand out in my mind from 2015.  The first is the remarkable warmth of the first 3 months of the year, which collectively rank as the warmest Jan-Mar period on record.  The only years with anything even close to what we experienced in Jan-Mar of 2015 are 1934 and 1986.  If it seemed crazy warm last winter, it was. On the other hand, July was simply splendid, and came ...

The National Centers for Environmental Information released their analysis of global temperatures for December 2015 and the year as a whole and they are unprecedented in the instrumented record and "off the charts" in the sense that they almost certainly required a revising of the y-axis scale. Let's start with the last 3 months of 2015 (Oct - Dec).  During this period, El Nino was well developed and global mean temperatures were 1.84ºF (1.02ºC) above the 20th-century average and a whopping 0.47ºF (0.26ºC) above the next highest Oct-Dec period (2014). Source: NCEI December 2015 in particular was the first month in the instrumented record with a temperature a full 2ºF above the 20th-century average for the month. Source: NCEI Now for the worst-kept secret in the climate business: 2015 was the warmest year on record, and by a pretty wide margin, reaching 1.62ºF (0.90ºC) above the 20th century average. Source: NCEI This extreme warmth reflects both global...

The trough moving through northern Utah this morning is bringing some convective snowshowers to the Salt Lake Valley and the surrounding region. Radar imagery early this morning (1400 UTC, 0700 MST) showed some areas of higher (> 35 dBZ) radar reflectivity, with the speckled, cellular structures likely produced by stronger updrafts. Rimed snow crystals (small round balls below) could be seen at my place in the Avenues, although they were fairly small.  I wouldn't be surprised, however, if there was some decent graupel in other areas. Expect some valley snow showers at times this morning, which should be the epitome of if you don't like the weather, wait five minutes.  Accumulations of an inch or two are possible in areas that are fortunate to have more sustained snowfall. The recent storms have pushed Alta-Collins over the 75" mark for the first time this season.  Due to settlement, they are now fluctuating around that level.  I'm not sure if today...

I often tell people that total snowfall or peak snowpack observations don't always tell the whole story about how the quality of the skiing in a given season.  Seasons with near average snowfall (and peak snowpack) may have been good or bad ski seasons depending on when and how the snow fell and other factors such as temperature. Let' me show you some interesting numbers to illustrate this.  First, is it your impression that this year is a better ski season than last?  Most people I spoke with this weekend said yes and for my interests as a backcountry skier, this year seems to be much better than last. However, if we look at the snowpack in the central Wasatch, it's not much different than last year.  At Snowbird, the snowpack water equivalent is actually a bit behind last year. Source: NWS Any individual SNOTEL station can sometimes be a bit unrepresentative, but if we look at others in the central Wasatch, we see a similar result. For example, at the Mil...

Nearly as rare as a Bigfoot sighting, a photo of Professor Powder was captured today at Alta Ski Area.  As is almost always the case, heavy snow makes confirmation of the sighting difficult. However, his progeny were seen nearby, increasingly the likelihood he was in the area. Actually, I haven't skied much at all in bounds this year.  It was nice to get out today, although I somehow managed to bust out my sidewall.   My alpine skis were old, and now they are shot.  Bummer! The skiing will only get better as the day goes on, but I needed to return to town today.   The scene in the valley early this afternoon, with snow cover and rain reminded me of a winters day in upstate NY.  Grey, dreary, and terrible for skiing.  Thank goodness we have a big mountain range here to get above the snow level.

I have lived in Salt Lake City for 20 years and have seen dramatic changes in the Cottonwood Canyons during that period.  The canyons have always been popular, but transportation and parking for either resort or backcountry recreation is at its breaking point on many weekends and holidays.  This year we seem to be pushing it to a whole new level with major backups for the canyons and lots filling at resorts in both canyons.  Backcountry trailhead parking is becoming quite difficult.  Yesterday, the number of cars parked at Mineral Fork and Butler Fork was staggering. Perhaps there's a lot of pent up powder desire out there and this is just a temporary surge, but I doubt it.  Population projections for Utah show another million people will be here by 2035, possibly earlier depending on the estimate.  This is due to both internal growth (i.e., birth rate) and in migration, with those in the latter category frequently coming and staying here for the remarkab...