Wasatch Weather Weenies

My son and I spent the day at Alta today and enjoyed some really great lessons in mountain microclimates. The crest-level flow today was out of the southeast.  You can see this southeasterly flow in the 1700 UTC (10 AM MST) plot below, which shows southeasterly flow at the top of the Snowbird Tram, Mt. Baldy, and Top of Collins. Source: Mesowest As this flow ascended from American Fork Canyon, it formed a pronounced orographic cap cloud over Snowbird and Alta.  The flow then descended into upper Little Cottonwood Canyon, confining the cap cloud to over the upper reaches of Alta and Snowbird.  I have sketched out my guestimate of the flow looking up Little Cottonwood Canyon at about 10 am.  I suspect that the flow is crossing the barrier both within and above the cap cloud, but only the lower level airstream is moist enough to form a cloud.  Warming of the airstream as it descends and compressionally warms over Little Cottonwood Canyon results in the clou...

What I wouldn't give for a slam dunk, strongly forced, relatively high predictability snowstorm over northern Utah.  We keep getting these amplifying and digging upper-level troughs with hit and miss snowshowers and snowbands that are tough to anticipate.  In times like these, I find myself consuming a few too many of these. Forecaster's Friend was brewed by Utah Alum Kyle Tietze.  Kyle was a great student who passed away unexpectedly a few years ago.  We miss him greatly. The loop below shows the NAM forecast of 500-mb heights, clouds (b/w), and precipitation (color fill) through Sunday morning.  The main upper-level trough digs down the California coast and were mainly dealing with periods of snow showers that eventually concentrate in a snowband over central Utah on Sunday morning.   Direct NAM model output for Alta-Collins shows a few snow showers later today (tallying about an inch), dry conditions overnight, and then more snow showers t...

I was unusually excited about the inch or two of snow that fell at the U today.  It's amazing what a snow drought will do.  In case you are wondering, two inches so far at Alta-Collins (as of 2 PM). I have a busy day today, so consult with our students at utahskiweather.com for a forecast.

In a bad year like this, I sometimes feel jealous of my friends to the east in Colorado as I hear they are having a good year, and then I look at the data and I don't feel so bad. Below is a comparison of the  year-to-date long-term median and 2015 snowpack snow-water equivalent (SWE) at Snowbird and selected SNOTEL stations in Colorado.  Snowbird is on the left after which they are ordered in terms of descending median snowpack SWE.  I have included some of the snowier SNOTELs in Colorado along with a few from selected locations near major resorts. You can see why I jokingly say that a bad year in Utah is better than a good year in Colorado (or, more correctly, a bad year in Little Cottonwood is better than a good year at the resorts near and along I-70).  Although we are running well behind median at the Snowbird SNOTEL, we are still ahead of the SNOTELs near and along I-70 (Loveland Basin, Vail Mountain, Berthoud Summit, Copper Mountain, Beaver Creek Vil...

It's been a remarkable winter and we have the potential for ice and snow records in both the east and the west in the coming days. East: Great Lakes Ice Cover The snow and wintery weather back east have gotten quite a bit of press, but I haven't seen a lot on the Great Lakes ice cover.  Modis imagery from yesterday shows Lake Erie to be frozen over and Lakes Superior and Huron to be predominantly frozen over.  Lake Michigan is still hanging on with some open water (and producing some lake-effect clouds and snowfall), as is western Lake Ontario.  If you click on the image to enlarge it, you have a great view at the complexities of pack ice, especially on Lake Huron where large leads (cracks with open water) and openings can be found as the ice is pushed around by wind and currents. The NOAA Great Lakes Environmental Research Laboratory has some great products for monitoring the ice cover of the Great Lakes ( available here ) and allowing for comparisons back to th...

As Napoleon learned all to well, all bad things come from the east.  A walk on campus this morning is a bit more challenging that it has been in a few weeks given the cooler weather and the blustery winds.  Here are a few peak gusts since 11 PM last night from around the area: Farmington/I-15: 68 mph Mouth Parleys Canyon: 62 mph Centerville: 54 mph Bountiful Bench: 54 mph University of Utah: 53 mph Hill Field: 52 mph Fruit Heights: 51 mph Pretty much everyone is getting in on the action in this one. [ Addendum @ 11:08 AM : Everyone along the east bench of the Salt Lake Valley and the northern Wasatch Front - JS]. The time series from the Mouth of Parley's is quite interesting.  Winds have been steadily out of the east since late Saturday.  Although it is not unusual to have strong easterly flow at this location at night and in the morning, note that the easterlies persisted through the day yesterday, and then reached their maximum strength this morning wi...

This snowfall measurement brought to you by The Home Depot In a season in which we are seeing seeing remarkable snowfalls in the east (a lot of snow) and in the west (not enough), I've been dealing with a number of questions concerning long-term snowfall trends and records.  Answering these questions is sometimes complicated by the warty nature of our long-term climate records.  We have a saying in meteorology that all observations are bad, but some are useful, and this is especially true for snowfall observations, which are probably the worst of the lot. Here are just a few things that affect snowfall observations: On what surface was the snow depth measured? How frequently were observations taken? Was the measurement taken right after the storm or a couple hours later? Was the measurement taken right after the precipitation changed to sleet/freezing rain/rain or a couple of hours later? How hard was the wind blowing? Was the measurement location sheltered or ...

Some large snowfall contrasts were observed last night in the Wasatch Range which are the result of the spotty nature of the precipitation and the relatively low density of the snow (~6% water content).  The latter allowed a relatively modest amount of snow-water equivalent to produce some fairly significant snowfall totals. From about 0100–0600 MST (0800–1300 UTC) Alta-Collins picked up a quick 8 inches of snow.  During the same period, Snowbasin's Middle Bowl observing site got about 2 inches.  Ski area reports from this morning generally show totals of 9-12 inches in the upper Cottonwoods, 4-5 inches on the Park City side and around 2 inches at Snowbasin. Reports from the Cottonwoods might seem a bit uneven, and I suspect this may simply reflect when they took their observations this late last night or early this morning as that was a period of fairly rapid accumulation. The radar loop below shows the spotty nature of the snowfall overnight and early this morning. ...

Natives awoke this morning to fear and pandemonium as a geologic feature that has bordered the Salt Lake Valley since the beginning of human settlement was......GONE! That's right, the Wasatch Mountains were obscured entirely from view.  What sort of immortal could pull off such a magic trick?  Well, it turns out that this has nothing to do with supreme beings or the end times, but instead an extremely rare phenomenon known as snow. Chances are you haven't seen snow before.  It's a strange substance comprised of frozen water (known as ice) that can take many forms.  There is the famed stellar dendrite, an endangered species once known for providing sublime ski conditions.  There's also graupel, a styrofoam like ball that is soft and spongy.  Photos taken from an ancient time show the remarkable diversity of different types of snow that can fall from the sky.  We're talking wizardry here! Source: http://www.inscc.utah.edu/~tgarrett/Snowf...

After a warmup for today and tomorrow, it's fairly predictable that Mother Nature will be bringing cooler weather to northern Utah this weekend, but determining how much snow she will bring to the mountains, aye, there's the rub. We have seen this movie a few times in the past several weeks.  An upper-level trough digs into the western United States on the downstream (eastern side) of the long-wave "death ridge."  The models do a reasonable job with the long-wave pattern, but the challenge predicting the strength and structure of the upper-level trough and how it impacts precipitation over northern Utah. There are a number of ways to examine the difficulties of forecasting an event like this. One way is to examine a series of model forecasts all valid at the same time [in the loop below, 1200 UTC (0500 MST) Saturday].  Note how in the upper panels there is considerable variability in these model solutions with regards to the structure and strength of the upper-lev...

Mother Nature clearly is taking it out on eastern North America.  Punishment for Ottawa and Washington D.C. not taking leadership on addressing global warming?  I don't know, but check out the map below, which shows the departure of yesterday's average temperature from average.  Super cold in eastern North America and western Greenland, whereas it is near or above average across most of the rest of the northern Hemisphere (notable exception in northwest Russia). Source: ESRL Meanwhile, on the other side of the continent, check out the graph below which shows the average February temperature in Salt Lake City from 1928 to this year, the latter through yesterday.  You want to talk about an outlier, well here it is.  Average temperature so far this year is 48ºF.  Next warmest is 1995 (42.3ºF).  However, I just looked at the latest forecast models and it looks like we're going to be losing some of that lead by the end of the month. Source: ACIS ...

I've always been fairly apathetic when it comes to Boston, but they are really starting to tick me off.  Although I didn't like it, I could live with the Patriots beat the Seahawks in the Superbowl.  However, being trounced by them in the snowfall department is entirely unacceptable. Here are a couple of graphs for you.  The first is the accumulated snowfall at Boston's Logan Airport (green line) compared to climatology (brown line) since January 22nd.  Total accumulation 90 inches compared to an average of 10. Source: NOAA The second is for Alta for the same period.  Total accumulation 11.5 inches compared to an average of 67 (note scale change). Source: NOAA In addition, the 90 inches that Boston has received exceeds the average for Alta in the period.  Crazy stuff.

This is a repost of a book review from last summer.  Seemed appropriate to do again. Available at Amazon in  hardcover  and  kindle  editions For those of you with an interest in climate change in the western United States, pick up a copy of  The West without Water  by B. Lynn Ingram and Frances Malamud-Roam. It is easy to assume that our knowledge of climate is confined to the so-called instrumented period (extending back about 150 years except at a couple of locations), but geologists, oceanographers, ecologists, and other scientists have learned a great deal about climate change, variability, and extremes  (floods and droughts) through the study of climate proxies – ice cores, tree rings, lake and ocean sediments, and other clues left behind by mother nature. The West without Water  lays out the remarkable story that these climate proxies tell about the climate of the western United States, with emphasis on California and the ad...

Speechless.

All the skiers in our mountain meteorology group are catatonic.  Some of what I heard them mumbling about as they looked at the computer models today: "The GFS run is the worst I've ever seen." "We're on to 2015/16." "I'm going to the desert." How bad is it?  Well, here is the total accumulated precipitation for the next 384 hours (16 days) through March 1st from today's GFS.  Much of Utah has no precipitation, with just a sliver of the northern portion observing something between 0.01 and 0.10 inches. Source: NCEP Even the chances of snow this Sunday and Monday are evaporating before our eyes.  The models have shifted the trough eastward and are generally keeping the precipitation to our east.  Perhaps we'll get a few snow showers in the mountains, but not much more.  Here's our downscaled NAEFS ensemble forecast for Alta-Collins for the next 7 days.  Most of the ensemble members give us nothing.  A handful call for a...

Even if the pattern shifts and starts producing heavy snowfall, the winter of 2014-2015 will probably go down as one of the worst if not the worst snow years in Pacific Northwest history. The ski season has been an unmitigated disaster.  Snoqualmie Pass is home to four ski areas, all with base elevations near 3,000 feet.  Here's what it looked like at the Summit Central ski area this morning. Source: http://www.summit-at-snoqualmie.com/ How bad is this year?   Data collected by the Washington Department of Transportation shows that Snoqualmie Pass averaged 400" of snow the past five winters .  The average accumulation by February 10th was 205".  This year they've had 79" and obviously a lot of that snow has melted. If you have a season's pass for the Snoqualmie Pass ski areas, Crystal Mountain will let you ride for free, but if you go there, here's what you'll find. http://crystalmountainresort.com/ Yup, no snow at the base.  What'...

Our computer models are hinting at a significant shift in the large-scale pattern over western North America. For some time, we've had a ridge locked in over us.  We had a modest cool down with the frontal passage on Monday, but temperatures have remained well above average.  The forecast below from the ECMWF is for 5 PM tomorrow and it shows what we have seen for some time — a high-amplitude ridge over western North America. The models, however, are calling for that ridge to weaken late this weekend and early next week, with a new ridge forming further west over the eastern Pacific. This is a fairly significant shift for our weather as it will mean a return to more seasonable temperatures, at least temporarily, and I think we can be fairly confident that cooler weather will be here early next week.  The pattern is not one in which we typically see a lot of moisture, so I'm not overly excited about deep-powder prospects, but the models are hinting that we may ...

Where are you Steenburgh winter? A few years ago I coined the phrase "Steenburgh winter" to describe that period of the year during which there is both a deep snowpack and a low-angle sun (see Last Day of Steenburgh Winter from February 2011).  The idea was to highlight the part of the winter that provided the creme-de-la-creme snow conditions for backcountry skiing.  Steenburgh winter begins when the Alta-Collins stake hits a 100 inch snow depth as that's when nearly all of the backcountry becomes skiable.  There are many areas I won't tour until there's that much snow on the ground.  It ends on February 10th, which is when the sun is beginning to become increasingly caustic to snow, certainly on south aspects and, as we progress into spring, other aspects as well.  There is certainly great skiing to be had outside of Steenburgh winter, but the idea here is to describe that period during which there is both abundant snow cover and the ability to ski most a...

Yesterday, Andrew Freedman of Mashable described the forecast for today for Boston as a "Wicked Pissah" and I like that so much that I'm going to hijack it and use it to describe the overall pattern that is currently dominating the weather over North America. We could call this a high amplitude pattern, but for today, it's simply a "wicked pissah!" In the far west, this pattern is a wicked pissah for everyone who loves snow or watering their lawns in the summer.  The snowpack in the Sierra and Cascades is dire.  Further inland, Montana, Wyoming, and Colorado are sitting near or slightly above climatological snowpacks in the upper elevations, but the Wasatch are struggling.  Alta-Collins this morning sits at 66 inches.  More on that in a minute.   Back in Boston and along the eastern New England coast this is quickly turning into a winter for the ages as multi-day snow accumulations and snow depth on the ground are near, at, or above all-time marks ...

A lot of people have been asking me if the warmth and poor snow this year (especially at lower elevations), as well as the string of poor snow years since 2010-11 is a long-term trend.  The answer to that question is probably not, but with a few caveats, and here's why. The climate history of the western United States is one characterized by large variability.  In other words, fluctuations from wet periods (sometimes called pluvials) to dry periods (droughts) within seasons, from winter-to-winter, or even from decade-to-decade, is the way the climate behaves in the west. If we look at the November to April snowfall history at Alta, for example, we see large ups and downs from year to year. Most years fall between about 380 and 600 inches, although there are some that are drier and some that are snowier.  If you look carefully, you might even notice a bit of what we call decadal-scale variability with the early part of the period being less snowy, the 80s and 90s being...

The Heat Miser is in total control over northern Utah.  Source: RankinBass Yesterday's high of 65ºF at the Salt Lake City Airport was not only a record for the day, but the earliest 65ºF observed for the calendar year. We'll make a run at records again today.  The record for the day is 63 and anything above 65 would also be a record earliest observed for the calendar year. I've been in DC all week participating in a winter weather forecast experiment being run by the National Weather Service.  It's been cold with no snow here.  Looking forward to returning to valley warmth and mountain snow, even if the latter isn't of our usual high standards.

It has been a warm and dry winter (December to January) this year in the central Wasatch, but there have been similarly "bad" years in the past. If we look at the average temperature at Alta, for example, the largest outlier is not this year, but December 1980 – January 1981 (hereafter just 80–81). There's a lot of missing data in the record for Alta, so I thought it might be wise to look at another site, in this case, Silver Lake Brighton.  Indeed, it is 80–81 period that is the warmest on record. The large-scale patterns for the two periods are actually pretty similar.  80–81 featured a western North American ridge and a deep North American trough. The pattern is similar in 14–15, although it's not quite as amplified over the continental U.S. If we look at the 700-mb temperatures over northern Utah, what we find is that indeed it was warmer in 80–81 than 14–15 by about 2–3ºC. So, it was a warm December to January period this year, but ther...