Wasatch Weather Weenies

Yesterday's storm was great, exceeding expectations in the valleys and mountains.  It has been a while since we've had a storm that came together to maximize precipitation generation, but yesterday's did.  The radar filled in nicely as the trough approached, precipitation continued pretty much without abating throughout the event, and the post-trough, northwesterly flow was quite productive.  It was also a big event in the valley as well as the mountains.  Here are some numbers (lowlands courtesy NWS): Wasatch Front Lowlands Fruit Heights through 8 PM Thu: 1.42" Bountiful Bench through 8 PM Thu: 1.27: Holladay through 8 PM Thu: 1.21" Alpine through 5 PM Thu: 0.90" Wasatch Mountains Ben Lomond Peak: 1.2" SWE Snowbasin-Middle Bowl: 1.07" SWE Alta Collins: 1.36" SWE/13" Snow Aspen Grove (Mt. Timpanogos): 0.88" Sundance-Mid Mountain: 0.86" SWE I've emphasized the higher lowland totals above, but an inte...

I love satellite images like the one above for 1700 UTC (1000 MST) this morning with an overlay of the 500-mb heights (black) and absolute vorticity (colors).  These are two fields commonly used by meteorologists to track upper-level troughs, which I've identified with some pretty ugly red lines.  I also highlighted my best guess for the position of the developing low center with a red "L." You can see quite nicely the two systems that will impact Utah through the weekend.  The first is currently centered over Nevada and precipitation associated with that system is moving into northern Utah this morning.  At 10 am it was 35ºF at Snowbasin Middlebowl and 33ºF at the base of Snowbird.  Yup, another day for a good shell.  Freezing and snow levels will drop as the system moves in and precipitation picks up, but will be near 7000 feet this afternoon. The models currently call for a decent break between systems late tonight and tomorrow, with the second mo...

Much to talk about today.  First, have you seen the sunsets the past couple of days?  Unbelievable.  The photo below, taken Monday doesn't do them justice, but does capture a nice sun pillar if you look close. The presence of altostratus clouds (upper right of photo above) and lenticular (mountain wave) clouds has certainly helped paint the scene, but I'm wondering if we might have some aerosols, possibly Asian dust or pollution, moving over us in the upper atmosphere to give us a bit more orange tint than usual.  Perhaps someone can dig in and have a look as I have other important things to keep me busy today. Storms After a sunny day today, things are looking pretty active for Thursday through Saturday and possibly Sunday as two major troughs embedded in the southwesterly to westerly large-scale flow rumble through the state.  There is a lot going on, so I'll summarize quickly with two graphics from the 1200 UTC NAM.  The first is the total preci...

Blue skies, mountain wave clouds, and heavenly spring weather at the U @ 2:30 PM 25 Feb 2014 At 7000 feet and below, everything sure looks and feels like April right now.  There's no snow in the valley, Mountain Dell is closed for cross country skiing, and snow is barely apparent along SR-224 near Kimball Junction. Source: UDOT/NWS At an elevation of 6000 ft, the Ben Lomond Trail SNOTEL is the only one in the Wasatch that I am aware of that is below an elevation of 7000 feet.  This is a snowy location with a fairly significant snowpack compared to the Park City area (as usual), but even there, the snowpack SWE is pretty much what one would expect in mid April.  There's even some evidence of a modest decline, although that could also be spurious. Source: NRCS Finally, we have the temperatures.  At 2:05 PM, the temperature at the Salt Lake airport is 63ºF, which equates to the average high on April 21st.  The only thing that isn't April like is the...

The Daily Utah Chronicle, January 28, 2014 The University of Utah administration talks a pretty good game when it comes to sustainability.  Several years ago they formed an Office of Sustainability, now the Sustainability Resource Center , to institutionalize campus-related sustainability initiatives.  There is a President's Sustainability Advisory Board to "recommend policies that propel (my emphasis) the campus toward greater sustainability to the University President."  We even have a new Chief Sustainability Officer. The U also has the following Sustainability Principles : Integrate sustainability into education Track and reduce greenhouse gas emissions Make the campus a "living laboratory" with experimentation and applied research Invest in initiatives that reduce dependence on fossil fuels Capture and reinvest net savings into additional projects Minimize waste through reuse, recycling, and reduction, as well as composting Purchase susta...

Spring has sprung in the Salt Lake Valley where we are being treated with an incredibly spectacular bluebird day.  The high temperature at the Salt Lake City airport may eclipse 60.  I wasn't in the mountains today, but suspect the skier grins are a mile wide, although the sun and high temperatures may be spoiling the snow a bit on some aspects.  Unlike spring, when the snowpack is sometimes dirty and dusty, it is currently bright white, providing spectacular contrast with the blue skies. With the warm weather, high snow levels, and valley rain we have had the past couple of weeks, I feel like this cool season we've had two falls and a spring rather than a fall, winter, and spring.  Yeah, it was cold, snowy, and polluted in the valley in December and January, but the mountain snowpack was fall-like until only recently. Mild weather looks to continue through the coming work week, with a warm storm late in the week.  If everyone gets their bikes out, maybe ...

You can find the advertisement above in the University of Utah campus bookstore.  It has clearly been composed to appeal to Utah skiers and snowboarders, including the use of the phrase "The Best Snow on Earth", which is cleverly changed from The Greatest Snow on Earth, which is trademarked by the State of Utah.  There is, however, something fundamentally wrong with this ad, at least as far as Utah is concerned.  Can you spot it?

Once again, the storm track is tantalizingly close, but not close enough to bring anything in the way of a major storm to the Wasatch over the next 4–5 days. The pattern this morning is characterized by a high-amplitude ridge over the Gulf of Alaska, with toughing over the upper midwest of the U.S.  This results in strong northwesterly flow at upper levels from Washington into Colorado. Such a pattern frequently results in strong downslope winds to Colorado's Front Range, and wind gusts last night at the National Center for Atmospheric Research's Mesa Lab reached 90 miles per hour. Source: NCAR This particular pattern is fairly stable and expected to persist over the next few days.  A number of disturbances rippling through the flow will bring mountain snows to the Pacific Northwest, Wyoming, and lesser amounts to portions of northern Colorado, but as things look now, we're largely shut out. Source: NCEP We've seen this movie already a few times this ye...

Source: http://www.keepcalm-o-matic.co.uk After a 2nd winter of hideous air quality, we are now approaching the end of the inversion season.   As shown in the graph below, days with PM2.5 concentrations > 17.5 (blue) and > 35 ug/m3 (red) are most common during the heart of the winter and drop off dramatically after the 7th week of the year (Feb 12-19).   Source: Dave Whiteman, University of Utah Thus we are almost out of the woods.  There are, however, some PM2.5 > 35 days all the way to the 8th week of the year (Feb 26-Mar 4) and an elevated frequency of PM2.5 > 17.5 through the 10th week of the year (March 5-12) (events after that are probably due to blowing dust).  For that reason, I won't stick a fork in it just yet.   Nevertheless, poor air quality events later in the cool season (e.g., late Feb and early March) typically require a good snowstorm followed by a long-lived ridge.  We do have a ridge forecast to build ...

We often think about precipitation being collocated with a surface cold front, but this is not always the case.  Indeed this morning we had some scattered rain and snow showers providing some appetizers ahead of the front, but the main course, a well developed frontal snowband, has developed nicely over the Salt Lake Valley and southern Great Salt Lake over the past hour well behind the surface cold front. As shown in the meteogram below, the winds at the Salt Lake City airport shifted from southeasterly to northerly from 0730–0940 MST this morning. However, the frontal snowband developed well behind this surface front.  One can see it filling in over the southern Great Salt Lake, well behind the surface front, at 1800 UTC/1100 MST (click to enlarge). The frontal band is now over us at the University of Utah.  It should give us a couple of hours of entertainment, but should be out of the way come rush hour.

Norwegian skier Chris Jespersen races in the 15 km cross country final (Getty Images) If you are a ski junkie like me, you've probably been seeing some crazy stuff at this year's Olympics.  Temperatures have been ridiculously warm and this has clearly had an impact upon the events.  It's too bad that NBC has ice skating on the brain.  With a little thought and marketing they could easily take advantage of the scantily clad uber-athletic cross country skiers to boost ratings. American Sophie Caldwell in the 10 km classical final (AP Photo Matthias Schrader) Everyone races in the same conditions (for the most part, although warmer snow typically deteriorates more quickly, resulting in a bigger handicap for later skiers than occurs in cold weather), but this is the Winter Olympics, not the Spring Olympics, and I miss seeing races on cold, fast snow.  The problem with Sochi is that it has a somewhat maritime snow climate that is susceptible to thaws and rai...

Yesterday (Saturday) afternoon's convective storms produced some thundersnow and some big graupel, the latter still quite apparent on the hill today (Sunday), including these samples from Alta's High Rustler. I often tell people that when it comes to resort skiing, I prefer graupel over cold smoke.  Graupel is high density and makes the steeps smooth as a baby's bottom.  Unlike high density wet snow, it lacks cohesion and is quite supportive.  Yesterday's storm produced 3 inches of snow with 0.42 inches of water.  That's a water content of 14%.  No need to thumb your noses at such high water contents as a few inches of graupel skis great. The blogger's son knows a good thing when he skis it and doesn't thumb his nose at a good graupelfest Yesterday's big graupel was the result of several factors.  One was the intensity of the convection.  Strong updrafts help to keep larger particles lofted longer, allowing them to grow to larger sizes. ...

If you like April, our current pattern is for you.  Minimum temperatures the past couple of days have been near typical highs and both maximum and minimum temperatures are more typical of what one sees in mid April than mid February.   Source: NWS Alta-Collins currently sits at 95 inches, within reach of the coveted 100 inch base mark.  It's great to have some cover finally, at least at upper elevations.  It looks like we may crack 100 in the coming week.  

Looks like about 1.2 inches of snow-water equivalent at the Alta-Collins observing site so far during this event. Source: MesoWest Although earlier model runs called for things to taper off later today, this morning's call for periods of heavy precipitation to continue through Friday with the 12-km NAM generating another 0.7 inches of snow water equivalent by late Friday (see lower left hand panel below).  Source: http://weather.utah.edu Then we will have a very warm weekend - afternoon ridge-top temperatures at 11,000 feet are forecast to be in the low 30s.  Bring wax and sunblock for the resorts and enjoy a long and leisurely lunch.  Given the heinous avalanche conditions and what looks to be anything but the Greatest Snow on Earth on lower angle terrain,  the best option for backcountry skiers might be heading south to Zion or Moab for mountain biking, hiking, or rock climbing.

That's my favorite post title when we are in a stormy pattern and it still appears like we are on track for another pasting related to the inland penetration of another potent atmospheric river, as discussed in previous posts.  As I write this at 10 am MST, snow is falling at upper elevations in the mountains and we have a classic "cloud storm" scenario in the Salt Lake Valley in which the sky is full of virga, but just a few raindrops are surviving to reach the ground. This morning's "cloud storm" from the Salt Lake City International Airport This cloud storm scenario occurs when the moisture and dynamics for precipitation development are elevated and we have dry air at low levels, as can be seen in this morning's sounding.   Source: NCAR/RAL Forecasts are largely on track from yesterday with atmospheric-river-related precipitation spreading into northern Utah today and persisting through tomorrow.  In the upper Cottonwoods, the model forec...

Our second atmospheric river event in a week's time is setting up over the Pacific Ocean with a tremendous export of tropical moisture from the area near Hawaii streaming northward toward the Pacific Northwest. 1800 UTC 9 Feb – 1800 UTC 11 Feb 2014 GFS analysis of 925 mb wind (vectors) and integrated water vapor (mm, color contours with warmer colors indicating higher values).   Over the next 36 hours, the atmospheric river will move eastward and sag southward.  By 5 PM tomorrow (Wednesday) afternoon, the axis of strongest water vapor transport will be draped across southern Idaho and Wyoming.  As was the case with the atmospheric river event this past weekend, the strength of the water vapor transport over the interior will be unusually high for this time of year with a frequency of occurrence during this 3 week period of about once every 5 years or rarer. It certainly looks like the upper-elevation mountains of southern Idaho and western Wyoming are going t...

A drippy, foggy Monday morning in Salt Lake City This morning dawned with Seattle-like rain and fog in the Salt Lake Valley and Cascade-like conditions in the Wasatch Mountains where high-density snow continues to pile up in the upper elevations.  Water and snow storm totals reported on the Utah Avalanche Center web site this morning range from 2.87"/30" at Alta to 46"/6.94" at Sundance.  Logan and American Fork Canyons remain closed and tragically, two deaths have occurred in backcountry avalanches.   The storm should wind down today, with a break in the action tomorrow.  Beyond that, I hope you like the Northwest weather as we're going to get more of it.  A broad, low amplitude ridge remains over the region throughout the week, with another push of moisture into the northern mountains likely late Wednesday and Thursday.  Yes, it will be another atmospheric river event, with the tongue of tropical moisture that will be coming our way beginning to su...

Before discussing the balmy nature of the weather this morning, here's a very quick rundown of the water totals produced by the storm since 5 AM Thursday based on my eyeball estimates: Tony Grove Lake (8474 ft): 6.6 inches (Logan Area Mountains) Ben Lomond Peak (8000 ft): 6.2 inches (Ogden Area Mountains) Snowbasin Middle Bowl (7400 ft): 3.5 inches (Ogden Area Mountains) Alta-Collins (9662 ft): 2.3 inches (Salt Lake Area Mountains) I don't have much faith in any of the automated stations in Big Cottonwood Canyon that measure snow water equivalent, but the Utah Avalanche Center reports 3.21 inches for whatever site they are using (probably manual measurements from one of the resorts), so we will go with that. The Snowbasin-Middle Bowl and Alta-Collins observing sites are two of the most reliable in the Wasatch and they pretty much tell the tale for this storm.  Temperatures have risen dramatically through the period and are now a Cascade-like 35ºF at Snowbasin Middle Bo...

Finally! It was great to get in some storm skiing this afternoon.  Snowfall rates at Alta were pretty much pegged at about an inch an hour from 9 am to 4 pm. Source: MesoWest.  Looks like Alta-Collins is now up to 1.5 inches of water 17 inches of snow for the storm total and climbing.   I heard the lift lines were long in the morning, but I skied in the afternoon when the crowds were tolerable and the steady snow made for fun turns.  I even ran into a few members of the University of Utah Snow Study Team who having returned from the Tug Hill Plateau are trying to rack up as much vertical as possible.     Of course, the best way to finish a ski day is to come home and see the radar lit up upstream.  Voila! Source: NCAR/RAL Yup, things are looking good for more snow, courtesy of this latest atmospheric river.  Enjoy!