Wasatch Weather Weenies

As of 11:30 AM this halloween, it's already 68ºF at the Salt Lake City Airport.  The record high for the date is 76ºF and it's looking like we will make a serious run at that. Other than the fact that it may be windy later today, you can't ask for better Halloween weather.  That's great news for trick-or-treaters who won't have to cover up their costumes with bulky layers to keep warm. Tomorrow looks to be an exciting weather day with the potential for some thunderstorms, strong winds, and a vigorous frontal passage.  After that, much depends on the details of the postfrontal flows and the whims of the lake.  I still see a lot of spread in the model forecasts, although most are leaning towards periods of snow beginning tomorrow afternoon through Monday.  My most likely accumulation for the central Wasatch is 4 to 8 inches, less if the NAM wins (drier post frontal environment),  more of the GFS wins (wtter post frontal environment) and we also get the...

One of the most important papers in the atmospheric sciences was published by Ed Lorenz , the Father of Chaos Theory, in the journal Tellus in 1969 . The key finding of the paper is summarized in the second paragraph of the abstract: It is found that each scale of motion possesses an intrinsic finite range of predictability..."cumulus scale" motions can be predicted about one hour, "synoptic-scale" motions a few days, and the largest scales a few weeks in advance. Although we have learned that in some instances the predictability limits for atmospheric phenomenon may be longer than suggested by Lorenz in that paper, the general result that larger-scale weather phenomenon (e.g., cyclones, upper-level waves) can be predicted with greater lead time than mesoscale weather phenomenon (e.g., fronts and mountain waves) and especially smaller scale phenomenon (e.g., precipitation generated by convection) is critical to consider in weather forecasting. A great exam...

My graduate advisor, Cliff Mass, provides yet another sobering assessment of U.S. numerical weather prediction in his blog today .  Be sure to give it a read.  Many of you are well aware that the European Center for Medium Range Weather Forecasting (ECMWF) is currently the gold standard for numerical weather prediction.  There are a host of reasons for this, but inadequate computer power for operational numerical weather prediction in the U.S. is one of the more significant.  Further, while other nations are plowing forward with major computer hardware investments, the U.S. has failed to even purchase a computer with the $25 million that was provided to NOAA by Congress a year and a half ago. ECMWF U.S. National Centers for Environmental Prediction OK, those images exaggerate the situation, but this is serious business since advances in computer power and modeling capabilities offer significant potential to protect lives and property in the United States. ...

Porter Fox, Powder Magazine Editor and author of Deep: The Story of Skiing and the Future of Snow , will be giving three talks in Utah next week. 12:00 PM 4 November, Weber State University, Shepherd Union Building, Wildcat Theater 11:30 AM 5 November, Utah State University, Taggart Student Center 7:00 PM 6 November, Westminster College, Vive Gore Auditorium I believe all three talks are free and open to the public.

One storm is currently "raging" in the Wasatch, with another one possible this weekend. The storm presently underway is of the artificial variety as the resorts lay down a base of artificial snow in preparation for the coming ski season.  Below is a view of Alta this morning. Source: Alta.com I'm guessing someone will try to ski the white ribbon of death in the near future, if they haven't already. The second storm is fortunately of the natural variety.  Most of the medium range ensemble model forecasts are calling for an upper-level trough and surface front passage this weekend.  This is true of the GEFS ensemble below, as well as the gold-standard ECMWF ensemble. Source: NWS There is, however, some variability and timing and amount.  Some forecasts are calling for the action to get going early Saturday, others later Saturday.  Some suggest a few inches for the mountains, others a more significant event.  We've passed the so called predictab...

Looking southeast at orographic convection over the central Wasatch @ 7:45 AM this morning There's a lot to be learned by observing the weather during periods that are relatively benign.  Big storms are great, but you can't always peer into them and see the underlying processes that are contributing to precipitation generation.   Weak events, however, enable you to see some of the phenomena that ultimately contribute to big events. Early this morning provided such an example.  We had weakly unstable northwesterly flow impinging on the central Wasatch.  This is led to the development of orographic convection over the central Wasatch and adjoining Traverse Range (see photo above).  Orographic convection features strong updrafts that are initiated as unstable or potentially unstable flow is forced over a mountain range.  Typically the intensity, depth, frequency, and or spatial coverage of the updrafts is greater over the mountains than the upstream l...

Although we will see a few snow showers today and tonight in the high country, perhaps enough to coat the ground in places, it appears that October will go into the books nearly snow free as the rest of the week through Halloween looks dry. For those of you looking to make turns, Gunsight currently has a 0-2.5 cm base.  I'm using metric for marketing purposes. The metric base builder can be found elsewhere in the Alta–Snowbird high country... Most of this skiff of snow consists of large graupel, ice pellets, or small hail that fell during Tuesday's frontal passage.  I never know what to call precipitation that looks like this.  In honor of  The Princess Bride , perhaps we should call it "graupel of unusual size."  This mass collected in a local pit of despair. Elsewhere in the Wasatch, Lake Mary (left) is looking forward to a recharge this winter.  I don't know what the typical "spillway" elevation of Lake Mary is in October, but it surel...

There's a nice article in the latest Monthly Weather Review examining what is now the highest-elevation tornado documented in the United States (see Monteverdi et al. 2014 , access to the full article may be paywalled to those without a subscription). The tornado occurred in the Rockwell Pass area of Sequoia National Park at an elevation of about 12,000 feet on 7 July 2004.  Impressive photos of the storm were taken by Scott Newton, a backpacker in the area. Source: Monteverdi et al. (2014) Source:  Monteverdi et al. (2014) Documented tornadoes at such high elevations are quite rare.  The most famous is the F4-rated Teton tornado of 1987 (see Teton Tornado 25 Years Ago  by U Alum and retired Storm Prediction Center forecaster Jack Hales). No tornadoes for Utah today, but the NWS has a wind advisory out for much of western Utah including the Salt Lake Valley for this afternoon and evening. Source: NWS

The 2014 Utah Snow and Avalanche Workshop (USAW) will be held on Saturday, November 1, at the Southtown Expo Center.  As is the case every year, an excellent schedule is on tap to help prepare you for safe recreating in the Wasatch backcountry this winter.  Click here to see the schedule and purchase tickets in advance (click the "Add to Cart" button at the bottom). I'm pleased to be giving a talk during USAW on my book, Secrets of the Greatest Snow on Earth, which covers all the essentials of Wasatch weather and climate for skiers and backcountry recreationists.  We've pulled some strings and Weller Book Works should be on hand with signed copies of the book for purchase, a few days ahead of their general availability.  They are also taking advance orders at their Trolley Square location.  Pre-release sales have been high, so don't wait!

Mother Nature will be treating us with mild fall weather through Saturday and, given the lack of snow in the high country, I encourage you to seize the opportunity to get in some hiking, running, or biking either in the valley or the mountains. The NAM time-height section below pretty much tells the story.  We have some upper-level moisture moving through the area today, which will lead to some mid-and-high clouds at times.  After that, the warm, dry southerlies are in firm control through Saturday.   By late October standards, temperatures will be mild through the period, with temperatures on the top of Mt. Baldy (11,000 ft) rising today and remaining in the low-to-mid 40s through Saturday. High temperatures at the Salt Lake City airport today, Friday, and Saturday should be in the 70s. Temperatures on Friday and Saturday will likely be in the mid 70s and could approach the records for each day (78ºF in both instances). Enjoy!      ...

I am back in Salt Lake City and there is some weather outside today, but I'm having difficulty thinking about it in the wake of my trip through Europe. I've already done a post on Innsbruck (see The Foehn Giveth and Taketh Away ), but wanted to share some more of our experiences as they bear some relevance to long-term transportation planning for the Wasatch Front and Mountains. Innsbruck is a "small" city, with a population of 130,000, but like many cities in Europe, is relatively high density with a large concentration of restaurants, bakeries, cafes, and the like. It also has a remarkable public and mountain cableway system that provides incredible access to the mountains around Innsbruck.  First, there is the Nordkettenbahn, comprised of the Hungerburgbahn funicular and Seegrubenbahn and Hafelekarbahn aerial trams, which take you 5500 vertical feet from downtown Innsbruck to the top of the Nordkette or "North Chain" of mountains. As mention...

Many of you powder hounds out there have heard the terms "El Niño" and "La Niña" thrown around quite a bit in the context of seasonal prediction, but these are not the only long-term atmospheric oscillations that are potentially useful for looking into an upcoming winter. Ever heard of the Arctic Oscillation? In the 2nd installment of the series of posts giving the people what they want (speculation about the upcoming winter), we will take a brief look the Arctic Oscillation Index and its potential impact on monthly snowfall in the Wasatch. First of all, what is the Arctic Oscillation? The AO takes into account the difference in sea-level pressure between the Arctic and the mid latitudes (i.e. the continental U.S.). When the pressure is relatively low in the Arctic and relatively high in the mid latitudes, this promotes a predominately east-west jet stream and a "bottling-up" of colder air in the high latitudes. This is a positive AO phase. When t...

Before Jim left for his much deserved vacation to Europe, he asked his students to do occaisional posts. And since Jim is away I thought I would post about something he would never post about: a winter outlook based on current weather. The basic idea is that there are long term atmospheric connections that we do not yet understand, but we can still see their effects. So does our current dry October offer any insight on our winter ahead? Below is the SWE plot from the 2004 - 2005 winter at the Snowbird Snotel. By November 1st a whopping 13.1 inches of precip had already fallen and the snowpack at Snowbird was already comparable to an average January 1st snowpack! This winter would go down as one of the snowiest since the snotel first started reporting in 1990. Below is the SWE plot from the 1990 - 1991 winter. Total precip for October amounted to only 3.8 inches, 1 inch below normal, and the winter never recovered. But how representative are these 2 winte...

Is there a better way to stimulate one's corneas than to take a train ride across Austria and Switzerland?  I couldn't help but think about what it would be like to grow up in a picturesque village like the one below with huge mountains in all directions.  You've never heard of the village below or the mountain behind it, but that's just the point.  It's like this everywhere in the Alps.  So many mountains, so little time! We passed through St. Anton, home to one of the best ski resorts in Europe.  In 2001, the Salt Lake Olympic Committee sent me to St. Anton to observe weather support for the 2001 Alpine World Championships.  I felt this was an unnecessary expense, but they insisted, so I went.  I remember reading an article before we left saying that it was a great expert resort with a hedonistic nightlife.  If they were going to send me there, I was going to have a good time. I have a lot of good memories from that trip, but h...

The Foehn is a dry, downslope wind that occurs north of the Alps, although the name is sometimes used to describe similar winds in other regions.  The equivalent in North America is the Chinook wind that affects the high plains near the Rocky Mountains. When it comes to finding clear skies, the Foehn can be your friend.  On our current trip to Europe, we opted not to make reservations for the mountain part of our trip, but instead made reservations after arriving based on the weather forecast.  One of the reasons that we ended up in Innsbruck was the likelihood of Foehn conditions and mostly clear skies today. Innsbruck is in the northern Alps and the Karwendel Alps to its north can offer clear skies during the Foehn.  In addition, Innsbruck offers a lift system that makes the Snowbird tram look like a bunny lift.  This morning we ascended nearly 5500 vertical feet from downtown Innsbruck to the crest of the Karwendel Alps via a funicular and two aerial tram...

Fall Break has begun and I've taken advantage by traveling to Europe where I'll be giving a talk at the University of Bern in Switzerland next week. For a mountain meteorologist and outdoor enthusiast, visiting the Alps is an amazing experience.  The mountains are huge, the valleys deep, and the spatial contrasts in weather dramatic. I'm currently in Innsbruck, which is located the Inn Valley, one of the longest and deepest in the Alps. Source: Wikipedia Commons ( Map data (c) OpenStreetMap (and) contributors, CC-BY-SA) The mountains immediately north of Innsbruck rise more than 2000 m above the valley floor.  Today, Mother Nature really gave us a great view of those mountains with a beautiful double rainbow over the city. Of course, being in Europe has other advantages, such as a beverage fountain that includes wine on tap.