Wasatch Weather Weenies

Hard to believe that tomorrow is May 1st.  This is two years in a row with great skiing on April 30th. The cover in the Wasatch is incredible.  If we can get a corn cycle going, we could have some great chute skiing in the BC for the next few weeks. Tim Garrett send me some photos today from his new snowflake cam that Howie and the folks at Alta have been running the past several days.  I'm really looking forward to having these at full res and in real time next winter.  Here's a teaser. Source: University of Utah/ Center for Snow Science at Alta

Source: NCAR/RAL An active night of lake-effect last night, such as the band above, gives the Alta-Collins site 15" since yesterday afternoon.  The powder just keeps coming! I suspect some sites in the Salt Lake Valley are waking up to a pretty good coating as well, but the NWS has yet to post up their observer totals. Little Cottonwood is presently closed as they are shooting the highway this morning.  Anticipated opening is 8:30 am.  I think we all owe a debt of gratitude this year to the snow-safety pros who have had an incredibly long season.

After my last class on Wednesday, we bugged out to Moab for a much needed thawing out.  The drive back today was incredibly dramatic from a meteorological perspective, beginning in mild pre-frontal conditions in Moab where it was about 62F, and ending in scattered snowshowers and temperatures in the 30s.  We'll call it 240 miles and 24 degrees for alliterative purposes. 11 am on the Moab Rim Looking NW into the orographic cloud from just south of Price. It was post-frontal here, but as is often the case in Price during NW flow, we were solidly in the orographic rain and cloud shadow. Spanish Fork Canyon. About 5 PM in Salt Lake. Currently, convective snowshowers abound around northern Utah, with some indication of a bit increased intensity and duration downstream of both the Great Salt Lake and Utah Lake (a loop shows this better, but the best I can do on short notice is the still show below). There was a really nice banded, ragged cloud base over Utah ...

Beaucoup snowpack out there.  Let's have a look thanks to the National Weather Service Colorado Basin River Forecast Center web site. Tony Grove Lake (8400 ft) is at 64.7" of snow water equivalent (SWE), ahead of their highest previous water year, 1982. How about a lowland site in the northern Wasatch?  Ben Lomond Trail (6000 ft) is at 23.1" of SWE.  There has been some decline in snowpack the past couple of weeks at this elevation, but the total SWE remains near all-time marks (1984). Lookout Peak (8200 ft) near the top of City Creek Canyon, 54.1" of SWE, which puts it at a whopping 246% of average, the highest since site installation in 1989. Snowbird is at 72" of SWE, which incredibly is still a smidge behind the peak in 2005. You get the point.  The Snotel records for these sites go back 2 or 3 decades, so they are short-term climatologies, but it is safe to say that we have an incredible snowpack not only at upper elevations, but also at lower...

The Alta-Collins snow stake just hit the coveted 200" snow depth mark! It's now official.  The ski season has attained EPIC STATUS.  Time to celebrate with a cold one from my favorite brewery . In fact, I think they need to come up with a winter ale for next year to celebrate this momentus occasion.

I suppose I shouldn't rely on such non-scientific estimates, but Alta does a good job collecting snow data and speculating on a seasonal total of 700" being reached is fun. Alta was reporting a seasonal snowfall of 680" yesterday morning.  Since then, Alta-Collins has recorded 5" yesterday, 12" overnight, and 3" this morning. Fortunately, I can do this math with all my fingers and toes: 680+5+12+3=700!!!!!!!!!!!!!!!!!!!! Whether or not that will be the official party line from Alta, I don't know, but it's hard to imagine their PR department does math any differently than I.  Besides, there's another storm coming, so 700 is in the bag and the only questions now are will be get to a 200" base and will this ever end?  What is the Alta seasonal snowfall record?  Another storm is coming...

Lake-effect snow showers continue over much of the Salt Lake Valley this morning.  It looks like winter out my window.  Wish I was skiing. As we have seen in some lake-effect events, there appears to be weakly confluent flow over the Great Salt Lake and northern Salt Lake Valley. An ongoing debate around here concerns the mechanisms for this confluence.  Is it a result of the superposition of the large-scalel southwesterly flow with the thermally forced circulations of the Great Salt Lake, or a reflection of topographic blocking?  Concavities in terrain have been shown to drive confluent flow and increase precipitation rates in idealized modeling studies ( e.g., Jiang 2006 ).  We don't have a clean concavity given the basin-and-range terrain south of the Great Salt Lake, but there likely are concavity effects.  On the other hand, the confluence could be thermally driven.  Perhaps both play a role? Alta-Collins update: 14" new since 7 PM yesterd...

With the KMTX radar dead thanks to a lightning strike , one needs to resort to desperate measures to peer into our ongoing storm.  Fortunately, I have a secret weapon. The FAA operates a Terminal Doppler Weather Radar (TDWR) near the southeast shore of the Great Salt Lake.  The TDWRs were developed to help with the detection of wind shear, an important aircraft hazard.  They are also quite useful as precipitation radars, although the Bountiful siting, while advantageous for detecting low-level wind shear near the Salt Lake Airport, suffers from considerable beam blockage to the east (by the Wasatch) and south (by the Avenues foothills). A loop of TDWR radar imagery this morning shows lake-effect snow squalls moving off the Great Salt Lake into the Salt Lake Valley. Unfortunately, the east bench and the area around Alta is shielded by beam blockage, but the Alta-Collins stake shows 10" from 5 PM yesterday through 7 am this morning.  They are oh so close to a se...

The KMTX radar is presently down. It was struck by lightning and will not be up any earlier than tomorrow.  I'm really glad we don't have a team deployed doing soundings of lake-effect now as without the radar, the case would have been a total loss.

Pea sized hail (or perhaps better put, "grail" since it's almost more like graupel than hail) fell in the Avenues  with a thunderstorm just before 7 PM.  Ah, spring! Apparently, the ongoing cold weather can be attributed to a software bug on the National Weather Service computers. Courtesy Bill DeMong via Karl Weatherly

Feeling the itch for one last deep powder day before the season comes to and end?  Tomorrow could be the day, but it could pay to wake up and check the Alta-Collins snow stake or Snowbird Snowcam before calling in sick. Although there are times when one can bank on a powder day, there are other times when there are synoptic possibilities, but whether or not we get the goods for a great powder day depends on mesoscale processes that cannot be confidently forecast 24 hours in advance with current technology.  A good analogy is storm chasing in the midwest where the potential for tornadic thunderstorms can be forecast a day or two in advance (sometimes longer), but success on a storm chase depends on factors that are not predictable at such long lead times. This cartoon cracks me up, but have no idea who created it! Thanks to the anonymous comedic meteorologist.  So, tomorrow we have the possibility of a deep powder day, but whether or not Mother Nature bring...

The skiing isn't great right now, but it ain't bad and more like winter skiing than spring skiing.  Where is the sun?  Who cares.  We've had nearly 6 consecutive months of quality skiing with barely a hint of spring.  Today offered up another day of light snow, no crowds, friendly locals, and good skiing for 23 April. Winter 2010-11: The gift that just keeps giving. Erik on Gunsight. You can't complain about turns like this on 23 April. April hasn't been as good as last year, but it's been pretty good.  We've had a hell of a year.  I wasn't ready to stamp this year as epic a couple of weeks ago, but continued good skiing is getting us close.  Further, there's more snow coming.

We're sitting at about 180" at the Alta-Collins snowstake, with a peak thusfar this spring of 195".  The pattern has been unsettled the past few days, but we need a big dump to get us to the magic 200". Perhaps our last chance to take a run to 200" will be over the next 3-4 days.  The pattern remains unsettled, and the NAM model produces a fairly healthy trough passage with a prolonged period of cold, unstable northwesterly flow Monday night into Tuesday. The GFS model is also looking optimistic for snow during the period.  It's far enough out that we can't get too excited about the model forecasts yet, but they are showing the potential to get Alta-Collins to 200".  Further, they could bring some pretty good powder skiing back to the Wasatch.  Last year my best day of backcountry powder skiing was on April 30th.  Perhaps another late April repeat?  Stay tuned.

Source: NASA Goddard Space Flight Center On December 2, 2004, Richard Smalley, the 1996 Nobel Laureate in Chemistry, gave the Frontiers of Materials Research presentation at the Materials Research Society Fall Meeting in Boston.  An edited transcript of the talk entitled Future Global Energy Prosperity: The Terrawatt Challenge was then published in the Bulletin of the Materials Research Society.  I don't recall how I came across it, but since I can't seem to find it online (even in the BMRS online web site), I'm making it available here for your Earth day reading pleasure (or perhaps displeasure). Although the intro is somewhat dated and contains some political banter that you may or may not like depending on your political persuasion, it contains a very sobering assessment of the energy challenges we are facing.  In particular: In 2004, average global energy consumption was about 14.5 terawatts, or the equivalent of 220 million barrels of oil per day. Most (~80...

Strong winds associated with thunderstorms ripped through northern Utah this afternoon.  Several sites reported wind gusts of more than 65 mph, including the Salt Lake City Airport. MesoWest observing sites reporting wind gusts greater than 65 mph this afternoon. Several large trees were blown down.  Although some snapped, others fell over with the entire root ball (see Salt Lake Tribune story ).   Source: SL Tribune, courtesy Greg Farley. A contributing factor to these tree blowdowns is the rainy April we've had and the anomalously wet soils.  Wet soil is weak soil, and trees are more likely to pull up in the fashion above when the ground is saturated or near saturated.   

A line of powerful thunderstorms is moving through northern Utah.  The National Weather Service has issued a severe thunderstorm warning for several counties in northern Utah. Several sites have reported gusts in excess of 60 miles per hour.  The big one thus far is Ogden Peak with a gust of 104 mph.   An impressive 67 mph was recorded at KSLC airport.

Scattered thunderstorms moved across northern Utah not only yesterday afternoon, but also overnight.  The Salt Lake City Airport, for instance, reported lightning to the east at 0653 UTC (12:53 AM MST). A radar loop covering that time shows several strong cells moving across the Great Salt Lake and a line of strong convection late in the loop near the Utah-Idaho border. Many people are mystified by the development of nighttime thunderstorms, especially in Utah.   Are nighttime thunderstorms unusual? In a seminal paper on the diurnal variation of summer thunderstorm frequency,  Wallace (1975)  showed that in midwest of the United States, summer thunderstorms are more common at night than during the day.   The diurnal cycle of thunderstorm frequency in the summer.   The barbs indicate the normalized amplitude of the diurnal cycle (half barb=5%; full barb=10%; flag=50%).  Phase indicated by orientation.  From the north indicates midnigh...

As a meteorologist who skis, I live for cool stormy weather, but like many of you, I can't take it anymore!   It's time to join the Homer Simpson Angry Mob Fun Run and declare open season on Mother Nature.  These spring storms don't provide great powder skiing and do nothing but muck up the corn. We're in a bit of a break now, but I just looked at the short- and medium-range forecast guidance and unsettled weather continues for the next several days.  I wish we could send this weather to Texas where they could use a dousing for the wildfires have now charred a million acres . Is there a bright side?  Well, perhaps we can finally get the Alta-Collins snowdepth over 200" and the seasonal snowfall over 700" (we sit at 181" and 664" right now).

A line of thunderstorms rumbled through the Salt Lake Valley last night, with ice pellets pounding my north-facing bedroom window and waking me from deep slumber.   Students in my class that went high for the probability of thunder will be pleased as it did verify at KSLC airport.

Alta and Park City are about 10 miles and 1500 vertical feet apart as the crow flies, but the difference in weather and climate is mind boggling.  These web-cam photos are both from today, albeit at different times. Alta Park City Maybe they should start selling an Interconnect Tour that combines mountain biking and skiing?

It's feeling quite maritime out there this morning as temperatures and dewpoints are in the mid 40s, there are low clouds hanging all over the mountains, showers are widespread, and the snow level is quite high. I find it quite depressing to check out the weather cameras from the mountains. Nothing "eats" a snowpack like the combination of high dewpoint temperatures, low clouds or fog, and rain.  Here's a quick visual tour from below to above the melting layer. Wolf Creek Ski Area.  Looks like a Vermont ski day. Parleys Summit.  Looks like a Cascade ski day. Top of Snowbird.  Looks like a Sierra ski day. The morning sounding from the Salt Lake airport shows the freezing level to be at 6179 ft above ground level, or almost 10,500 ft above sea level.  The snow level is typically about 1000 feet below the freezing level.  Right now, the Alta-Collins observing site at 9662 ft is 32F.  They've received 2" of snow with .46" of water since midnig...