Monday, June 29, 2020

Bizarro World

It's sort of a bizarro-world situation right now with coronavirus running amok, wildfires threatening homes, and late June turning into late April.

Saturday night and Sunday, wildfires threatened homes near Lehi, Draper, and Saratoga Springs as two separate fires raged in the urban-wildland interface.  The Traverse Fire near Lehi and Draper was apparently caused by fireworks.  The cause of the Knolls Fire near Saratoga Springs remains undetermined.

The cooler weather today is a blessing, but conditions Saturday night and Sunday must have been difficult with strong winds from varying directions.

Observations from the flight park near Point of the Mountain show south-southeast winds Saturday morning through about 1300 MDT, then a shift to S-SSW, and finally a shift to north at about 1800 MDT.  Winds from about 1300-1800 MDT were sustained at 35 mph with gusts to nearly 50 and then after the frontal passage peaked with gusts over 60 mph. 

Source: MesoWest
The remarkable late-June airmass change is quite evident in the temperature trace which shows an afternoon maximum yesterday of 88˚F, a rapid drop in temperature of over 15˚F with the frontal passage, and then a continued decline to current temperatures just above 40˚F.  Thankfully, the lower temperatures, higher humidity, and lighter winds this morning should greatly assist firefighters.

We will thankfully be under the grips of this late-June trough through Tuesday.  It will be unseasonably cool today with valley highs in the 60s, which is more like late April.  The Alta Devils Castle webcam is even showing a trace of snow above about 10,000 feet. 

Tip of the hat this morning to all health-care workers, first responders, and anyone helping with relief efforts for all that you do. 

Friday, June 26, 2020

A State Divided

In our previous post, we discussed some uncertainties in the forecasts for early next week, with differences in the amplitude and timing of a late-June upper-level trough that was expected to affect Utah's weather. 

The model spread has decreased some in the past couple of days with both the GFS and the ECMWF now going for a solution that favors a frontal passage over northern Utah on Sunday (probably noon or later, but follow forecasts as this could change) with the front moving very slowly across the state through Tuesday.

On Monday, we will be a state divided meteorologically.  At 0000 UTC 30 June (1800 MDT Monday), the GFS forecast puts the surface cold front over central Utah, with unseasonably cold, northwesterly flow over the northern and western portions of the state and warmer southwesterly flow over southwest Utah. 

The ECMWF has a very similar solution, as illustrated by the surface temperature forecast below, with a 30˚F temperature contrast between southeast Utah and Cache Valley. 

Source: Pivotal Weather
Direct model temperature forecasts can exhibit large biases, so I don't use the absolute values of those numbers above for anticipating actual temperatures, but the National Weather Service is currently forecasting a high of 67˚F for the Salt Lake City airport on Monday, which would be 22˚F below average. 

Monitor forecasts for evolving details, but be prepared for big changes.

Wednesday, June 24, 2020

Late June Troughs

A weak trough will move over northern Utah tomorrow, lowering maximum temperatures in the Salt Lake Valley into the mid 80s and bringing a chance of scattered showers and thunderstorms. 

I mentioned how great it is that we keep seeing these troughs in my previous post, and there's a chance of another, stronger one, early next week, but the impacts on northern Utah vary substantially depending on the forecast model. 

The GFS forecast valid 1200 UTC (0600 MDT) Monday shows a deep trough over the northwest U.S. with a cold front moving through northern Utah. 

The GFS then brings the trough directly through the northern half of the state and by 1200 UTC (0600 MDT) Tuesday, forecast 700-mb temperatures are just below 0˚C, cold enough for snow in the upper elevations above probably 9000 feet, although possibly lower. 

However, the ECMWF has a much different evolution for northern Utah.  It stalls the trough over the Pacific states. 

We would probably see a cold frontal passage at low levels in that solution, but it's a tough call.  Additionally, it would be drier and snow levels would not be as low. 

Thumbnail 500-mb plots from the GEFS all show a trough over the western US, but with varying amplitudes and speeds. 

Source: Penn State E-wall
This means there's a great deal of uncertainty about how things will play out early next week.  In fact the ECMWF drags the trough very slowly across the western U.S. which would be a fly in the ointment for weather for much of the week as the 4th approaches.

The bottom line is that you should monitor forecasts in the coming days to see how this plays out.  Ahead of the trough we could see elevated fire-weather risk with wind and low humidities.  Near the trough, a chance of showers and thunderstorms.  Much will depend on track, intensity, and movement and the range of possible outcomes for any given location in northern Utah is quite large. 

Monday, June 22, 2020

A Pleasant June So Far (By Recent Standards)

The average temperature at the Salt Lake City International Airport for the first three weeks of June was 68.9˚F.  This is quite comparable to the first three weeks of last June (68.6˚F) and considerably cooler than the first three weeks of June 2015, 2016, 2017, and 2018, when mean temperatures were at or above 74˚F. 

Source: NOAA Regional Climate Centers
So, compared to recent standards, this has been a pretty nice June.  However, it's still about 2.4˚F warmer than the 20th century average for Salt Lake City.

It's also been a June of extremes.  Just check out the roller coaster we've been on below.  We hit 100 on June 5, the earliest 100 ever recorded at the airport, then plunged downward with highs of 60 and 55 just 2 and 3 days later, respectively.  We subsequently seen big swings continue through today.   

Source: National Weather Service
Today looks splendid with a high of 84 forecast for the Salt Lake City Airport by the National Weather Service.  Temperatures will climb into the low 90s by Wednesday, but then another trough moves in on Thursday.  The GFS forecast for late Thursday afternoon (MDT) shows the trough over northern Utah bringing a chance of showers and thunderstorms.  Hooray!

Climatologically, we are entering the least synoptically active part of the year, so each trough we see now is a blessing.

Sunday, June 21, 2020

The Days Are Getting Shorter!

Yesterday's summer solstice is behind us and the days are now getting (slowly) shorter.  There is still much summer and fall to enjoy, but the orbital parameters strongly suggest that ski season will come.

What the ski season will look like is a big question.  Perhaps we'll be close to a vaccine or there will be a treatment breakthrough that allows us to move forward as we have in the past.  We all hope that's the case, but there's also the possibility that our best strategies remain non-pharmaceutical interventions such as distancing, masking, etc., as they are today.

Some hints at what things might look like are being provided by resort plans in Australia, where resorts are beginning to open.  Traveller reports that resorts are beginning to open this coming week with what Falls Creek resorts calls "business as unusual."  It sounds like lift tickets are being sold in advance, chairlifts will be loaded with half capacity (unless riders are from the same household), lift line queues are being spaced apart, and skiers are being encouraged to bring their own lunches. 

It should be noted that Australia (and New Zealand), unlike the United States, have crushed the curve (cases per million people below, with New Zealand the unlabeled purple line).  Yet these practices are still being implemented. 

In Utah there will be other challenges.  How will people get to the Cottonwood resorts?  UTA busses on ski days are crowded.  Will anyone want to ride them if coronavirus is prevalent?  Should carpooling be encouraged if it means people from different households are social bubbles riding together?  What will traffic in the canyons be like on a powder day?  

Perhaps we might also see a major uptick in backcountry skiers, as occurred after the resorts closed last season and accelerating a trend that has been apparent now for many years.  This could put further pressure on parking at trailhead lots.

Perhaps I worry too much.  Let's at least hope we have a good snow season.  

Saturday, June 20, 2020

Stansbury Scenes

Probably 90% of the people who go out to the Stansbury Mountains are targeting Deseret Peak.  That's a worthy objective, but there are other options.  

Today, I hiked up to South Willow Lake, which similar to the Deseret Peak Hike starts in the Loop Campground at the end of the road in South Willow Canyon.  However, instead of taking the standard Deseret Peak Hike, one instead takes the Stansbury Crest Trail, which meanders along at an elevation of about 9000 feet.

The views are quite nice back to the east with green desert-range meadows contrasting with the now baked out Tooele Valley.  The Wasatch Range can be seen in the distance.  

It is the meandering through basins and upper-elevation meadows that makes the hike for me.  The lake itself is a worthy target, but isn't all that spectacular.

On the return, one looks directly at the famed Twin Couloirs, which are still holding a little snow.  

I skied the west one once with some friends in a previous life. 

According to the kid pictured below, they were skiable today, although the exit involved a much longer slog than we had.  Probably a bit more than 2000 vertical feet of snow free ascent and descent 

There were quite a few people out today and cars were parked in every nook and cranny near the trailhead when I left this afternoon.   

Friday, June 19, 2020

Mountain Wave Eye Candy

An incredible tweet below from @terrybnd with a time lapse of a mountain wave and downstream hydraulic jump.  I don't know precisely where it was taken, but they commented that they were enjoying "lovely scenes of radiation fog enveloping the fells on and around Ullswater" which is in the Lake District of England.

The video shows a classic high-amplitude mountain wave with plunging flow producing a "waterfall cloud" on the lee side of the ridge with a hydraulic jump and rotor developing immediately downstream.  The cloud structure on this occasion is ideal for tracing the flow.  A schematic of the flow in these situations is depicted below, although you have to mentally flip it and reduce the scale a bit to match that in the time lapse. 
Source: Whiteman (2000)
The flow during downslope wind events along the northern Wasatch, which tend to be strongest near Centerville and Farmington, is similar.  However, because the Wasatch are much taller than the hills of the Lake District, one typically does not see cloud plunging down the entire lee (west) slope.  Instead, one sees just a cap cloud on the ridge, as in the photo below from a modest downslope wind event in February (and my last trip through the Salt Lake airport just prior to COVID). 

In the downslope flow, the air sinks and warms, leading to a decrease in relative humidity and cloud evaporation.  However, evaporation takes time.  In the time-lapse above, the amount of warming, resulting decrease in relative humidity, and time needed to evaporate cloud droplets are not large or long enough to create a large cloud-free region (although there is some clearing).  Thus, the clouds provide a pretty good tracer for the low-level flow.

What you can't see is the wave-breaking region aloft, as depicted in the schematic.  While rotors and other features associated with downslope flow are hazards for aviation, the wave breaking region, which is often cloud free, is another as it is often accompanied by turbulence, which can be severe. 

Wednesday, June 17, 2020

About Last Night

Widespread precipitation with embedded heavy rain and thunderstorm fell across northern Utah last night.  Below is the radar image from 0548 UTC (1148 PM MDT) illustrating the widespread nature of the precipitation and, at this time, thunderstorms moving across the eastern Salt Lake Valley. 
Source: NCAR/RAL
The average 24-hour rainfall reported to MesoWest for the period ending around 8:30 AM MDT by stations along the northern Wasatch Front was 0.63" with a maximum of 1.61".  For the Salt Lake and Tooele Valleys it was 0.44" with a maximum of 0.82."

I suspect many people were surprised by this event and indeed it was a low probability possibility just two and a half days prior.  For example, below is a plume of downscaled Short-Range Ensemble Forecast system (SREF) forecasts for the Salt Lake City International Airport.  There are 26 forecast members that make up the SREF and 23 of those members produced less than 0.1" of precipitation and most produced a few hundredths or less. 

Another perspective on that forecast is provided below.  The ensemble mean precipitation is less than 0.1" across much of northern Utah except in the Uintas and the far north.  However, the ensemble maximum precipitation exceeds 0.5 inches in several areas. 

Another perspective is provided by the sequence of GFS forecasts below, which are 66, 54, 42, 30, and 18 hour forecasts of 6-hour accumulated precipitation (color fill) and instantaneous wind valid 0600 UTC (0000 MDT) 17 June (i.e. midnight local time last night).  Note how these forecasts initially kept scattered precipitation to our north, but trended to more widespread and heavier precipitation further south over time (but still not as much as observed). 

Finally, let's take a look at the evolution of NWS forecasts during this period.  To do this, I'll use their zone forecast products issued for the Salt Lake Valley at the times indicated below.  I'l begin with the forecast issued Sunday as it had no hint of precipitation.

  • 230 PM MDT Sun June 14: TUESDAY NIGHT...Mostly cloudy. Cooler. Lows around 50.
  • 259 AM MDT Mon June 15: TUESDAY NIGHT...A slight chance of showers and thunderstorms in the evening, then a chance of rain showers after midnight. Mostly cloudy. Cooler. Lows around 50. North winds 10 to 20 mph around midnight. Chance of precipitation 30 percent.
  • 245 PM MDT Mon June 15: TUESDAY NIGHT...Mostly cloudy with a 50 percent chance of rain showers. Cooler. Lows around 50. Northwest winds 10 to 20 mph.
  • 251 AM MDT Tue June 16: TONIGHT...Partly cloudy with a chance of rain showers and a slight chance of thunderstorms in the evening, then cloudy with rain showers likely and isolated thunderstorms after midnight. Cooler. Lows around 50. North winds 10 to 20 mph. Chance of precipitation 60 percent.
  • 1022 AM MDT Tue June 16: TONIGHT...Scattered showers and thunderstorms in the evening, then numerous rain showers after midnight. Mostly cloudy. Lows in the lower 50s. North winds 10 to 20 mph. Chance of precipitation 60 percent.
  • 202 PM MDT Tue June 16: TONIGHT...Mostly clear with scattered rain showers and isolated thunderstorms in the evening, then mostly cloudy with numerous rain showers after midnight. Lows in the lower 50s. North winds 10 to 20 mph. Chance of precipitation 70 percent.
So you can see how on Sunday, no precipitation was in the forecast, and then how the forecast evolved with time with increasing chances of measurable precipitation.  

The forecast issued at 230 PM Sun June 14 for the northern Wasatch Front was mostly cloudy with a 20 percent chance of rain showers and for the Cache Valley was mostly cloudy with a 40% chance of rain showers. 

So, this was a case in which "the model trend was not our friend."  The rain late yesterday and overnight was significant, exceeding the maximum precipitation at some sites for the calendar day (e.g., Logan, Ogden).  I think it is safe to say that forecasts issued on Sunday did not prepare the public for such a significant event.  This reflects a number of factors, including the evolving nature of the storm system, shortcomings in our current forecast systems, and limitations in how we currently communicate forecast uncertainty.  

It is a reminder to all of us who work in the weather enterprise that we have a lot of work to do.  

Monday, June 15, 2020

Are Campus Reopening Plans Realistic?

The University of Utah is slowly but surely rolling out more information about returning to campus for Fall 2020 at  Unfortunately, these web pages aren't data and there isn't a clear traceable way to see updates, but it appears some additional information has been added recently. 

There are two changes that I see as an improvement.  First, language related to face coverings has been strengthened.  It now clearly says that students must wear face coverings in class.  Second, the the faculty and staff information page at states that on-campus office work is allowed but should be minimized, with remote work encouraged. 

Nevertheless, I think these plans, which state that "classes will resume — in a mixture of in-person and hybrid delivery — on campus on August 24" are overly optimistic and fail to face reality.  I favor an approach in which as many classes as possible are taught online and we do all possible to reduce risk for on-campus instruction of classes that cannot be effectively taught online including but not limited to lab and performance classes. 

The simple fact of the matter is that the United States and the State of Utah have failed to contain the coronavirus.  We've had months to reduce transmission, improve testing and tracing, educate the public on the importance of mask wearing and distancing, and reduce infections, and yet here we are with cases on the rise throughout the state.  The genie is out of the bottle and it is hard to put it back in.

The University of Utah has more than 24,000 undergraduate and 8,000 graduate students, plus faculty and staff.  Most commute daily to campus from all over the Salt Lake Valley, Wasatch Front, and surrounding region.  Parking is limited on campus.  Public transportation is essential, with distancing likely impossible at rush hour times. 

We can enforce distance and masking protocols all we want on campus, but the reality is that students are going to partake in risky behavior and bringing them together every day is a recipe for transmission.  It may be hard to believe, but I was a university student once and I can assure you I wasn't studying in the library 7 days a week.  As psychology professor Laurence Steinberg of Temple University wrote today in the New York Times, "Expecting Students to Play it Safe if Colleges Reopen Is a Fantasy."  He goes on to say that the safety plans being proposed are delusional and could lead to outbreaks of COVID-19.  I would have said will

There appears to be no organized method of providing comments to the University about the reopening plans.  I have been told to communicate via my department chair and college dean and encourage you to voice your opinions through those avenues as well.  It is clear that input from the faculty has resulted in some changes in plans over the past week or two.  I'm not sure how much student input has been solicited through this process, but it is important.  The "Project Marmalade" team that is putting together these plans is comprised almost entirely of administrators and has no student members.  They need to hear from everyone. 

Friday, June 12, 2020

Cooler Weekend Ahead

Highs in the 80s are quite tolerable in Utah, but 90s not so much.  Yesterday's high of 91 and today's forecast high of 95 are outside my tolerance limits.  

The good news is that we have some cooler air moving in tomorrow.  The NAM 850-mb (about 5000 feet above sea level) temperature and wind forecast valid at 1500 UTC (0900 MDT) tomorrow morning shows a cold front moving across northern Utah that should knock temperatures down for the weekend.  

National Weather Service Forecast for the Salt Lake City airport calls for a high of 85 tomorrow and a very pleasant 76 on Sunday.  

Enjoy, but keep your distance.  

Wednesday, June 10, 2020


A number of grassroots campaigns are holding a strike today for black lives (e.g., #ShutDownStem and #ShutDownAcademia) to focus on discussions with colleagues about anti-Black bias in the world and in academia.  My colleagues in the atmospheric and related sciences have a call to action for an antiracist science community at that I encourage you to read today. 

I regret that pursuing antiracist policies and culture has not been a greater priority for me during my career.  I am taking time today to reflect, listen, and understand.  In the future, I am committing myself to stronger advocacy for the promotion of antiracist policies and inclusive culture in my department and college, as well as across the atmospheric and related sciences. 

Tuesday, June 9, 2020

Little Cottonwood Canyon Transportation Alternatives

The Utah Department of Transportation has identified three alternatives for more in-depth study to improve transportation in Little Cottonwood Canyon.  Information is available at and you can also input comments from June 8 – July 10, 2020 via the web site or other avenues described at the site.

The three alternatives are summarized below, including capital and O&M costs.
I thought I would talk a little about the gondola option based on my experience in Austria last year.  We have also discussed this in a previous post in December 2019.

Stubai Glacier ski resort in the upper Stubai Valley south of Innsbruck has a tri-cable gondola similar to the one proposed in the third alternative above.  The gondola, labeled 3S Eisgrat I and II below and referred to as the Eisgratbahn, is the primary lift for accessing most of the ski terrain.  There is an old 4-person gondola, labeled Gamsgarten I and II that can also be used, but it has a limited capacity.

Stubai Glacier has an uphill lift capacity of 40,000 skiers.  For comparison, Alta and Snowbird combined have an uphill capacity of about 30,000 skiers.  At Stubai Glacier, it is sometimes possible to ski to the base, but more often than not, due either to lack of snow or avalanche hazard, the Eisgratbahn is the primary way for skiers to access and exit the ski area.

The Eisgratbahn has an uphill capacity of 3,000 skiers per hour with large capacity gondola cars traveling at about 17 miles per hour.  The video below provides some context.

Curiously, the alternatives summary above appears to undersell the transport capabilities of a tri-cable gondola by listing the number of people per peak hour via transit as 1,050. The text below suggests that for some reason, UDOT assumed a similar peak-hour ridership of about 1,000 people per hour.  The capacity of the gondola would be much higher than that, although this assumes you can get people to the base of the canyon at that rate (as well as extract them from the base of the canyon at the end of the day).

I have a number of questions about how this will be paid for, how much it will cost to ride, how gondola costs or tolling might affect public access to the canyon in summer as well as winter, etc.  Beyond that, here are some additional thoughts:

  • The White Pine Trailhead is critical for accessing the Lone Peak Wilderness area and parking there is extremely limited.  The current design has an angle station near Tanners Flat Campground.  Is there a plan to modify access to the Red and White Pine trails from that location? 
  • What is planned for ADA-accessible trails between stations?  If we are to build something of this magnitude, people with a wide range of abilities should be able to hike point-to-point along the gondola line.  
  • How does the mountain accord fit into this?  That effort to create a coherent plan for the central Wasatch appears to have languished and the web site,, isn't even functioning, at least this morning.  Building this gondola must be a component of a larger vision for the Wasatch Range.
  • This may be addressed in the EIS if I give it a deeper dive, but are we still dealing with a bottleneck at the bottom of the canyons?  A dedicated bus lane along Wasatch Boulevard is a positive step forward, but the combined traffic of Big and Little Cottonwood Canyons backs up beyond the proposed mobility hub and there are other bottlenecks as well.  A large capacity gondola is great, but only if people can get to it.
  • What about Big Cottonwood Canyon?  Although focus on Little Cottonwood may reflect political realities, it's disappointing not to see a canyon-wide plan.  Traffic issues to and within both canyons are intrinsically linked.
  • If built, the gondola will be used for decades, which means it will be operating in the summer in a warmer climate than today.  Gondola cars will need to be designed to deal with with ridership on hot summer days warmer than those we see today.  
I'm interested in your thoughts.  Feel free to add to the discussion in the comments below.

Sunday, June 7, 2020

Are Universities Being Realistic about Reopening?

As a professor and the parent two college students, I'm deeply concerned about university plans to "reopen" in the fall.

Reopening plans for the University of Utah, where I am a professor and my son attends, are available at  This web page is not very specific, but states that classes will resume "in a mixture of in-person and hybrid delivery," that fall break will be cancelled, and that instruction will shift to all online after the Thanksgiving break.  Physical distancing "protocols" will be in place.  All individuals "are expected" to follow state and local guidelines for wearing face coverings.

Not discussed at all but hopefully forthcoming soon, are testing protocols, how the university will define and deal with outbreaks, whether or not mask wearing will be mandatory, options for high-risk students, etc.

My daughter attends Arizona State and their reopen information is a bit more detailed and available at  They use branding to discuss what they are planning (e.g., ASU immersion, ASU sync, iCourses), but essentially the strategy is similar, although they are more explicit that some courses will be entirely online.  They are also more explicit about plans to use synchronous learning in which some students attend online while others attend in person.  They state that employees and students will be required to wear a face cover while in ASU buildings and in outdoor community areas where distancing is not possible.  They provide considerable information on testing availability and they like.

My view is that ASU is ahead of the U right now in terms of providing more detailed (but still not detailed enough) information to students and parents, but know the U is working to provide more detials.  However, I am still concerned about reopening at both schools and other institutions.

The coronavirus is a highly infectious disease often spread by asymptomatic individuals in indoor areas.  Per capita case rates in the United States are remarkably high and even in Utah they are higher than many other countries.  On June 1st, Utah reached 9,999 cases (call it 10,000), which is 3,125 per million people.  I've put that on a chart below (red dot) relative to cases per million people from several other countries to illustrate where we were on June 1.

Since then, cases have spiked, so instead of flattening the curve, ours is bending up again.

Given the prevalence of coronavirus in the community, the mobility and social interconnectivity of students, and the reality of in-person instruction and other learning activities, are universities being realistic about the potential for spread or outbreak and the effectiveness of hybrid teaching?

According to the Office of Budget and Institutional Analysis, during the 2019/20 school year, 24,485 undergraduate and 8,333 graduate students attended the University of Utah.  The U also had 2,167 full- and part-time faculty members.  I could not find a count on their site for staff, but suspect it would be several thousand (perhaps more) if we include administrative and research staff.  Basically, the University of Utah is a small city of more than 40,000 people, not counting the hospitals and medical facilities.

A large fraction of these people travel to and from campus from all over the metro area.  This often involves taking mass transit, which is often quite full during the morning commute.  People need to eat and get around between classes.  There are many choke points on campus.  Students are going to socialize.  Thus, the potential for coronavirus spread or outbreak extends beyond the classroom and even campus. 

Hybrid instruction is being sold as a option of providing an in-person experience with social distancing, but what this will involve at the University of Utah is unclear.  How often will students attend class?  Will the instructor need to teach simultaneously in-person and online?  Will there be online lectures with a portion of the class attending shorter, in-person classes?  Will faculty have the freedom to design an approach that works best for their topics and activities?  Is this really better than online?

Instruction varies tremendously at universities with a wide range of teaching topics, activities, and environments.  Some classes are nearly (or maybe completely) impossible to teach effectively online, others can be taught nearly as effectively online as they can in-person with the tremendous restrictions imposed by the coronavirus.  Thus, as a faculty member I'm interested in having some ability to decide what is best for my classes.   As a parent, I'm most concerned about my children receiving a good educational experience.  I support classes that can be taught effectively online taking advantage of that format in the hopes that other classes that my children take that really require in-person instruction have the best chance of being offered through the semester without a lot of abrupt cancelations or transitions to all online due to outbreaks.

Finally, there is the reality that the coronavirus will be on campus.  Outbreaks may necessitate switching to full online instruction with little notice.  Faculty, staff, and students are going to need to miss an above-average number of classes due to coronavirus or illnesses with corona-virus-like symptoms.  In some instances, the symptoms could be severe or worse.  Care for students who may quarantined far from home is a concern that I have as a parent.  There are other scenarios that I would rather not think about. 

Ultimately, I would like to see the following:

1. Strong encouragement of faculty and staff to continue to telework as much as is possible to reduce density on campus and transit (I believe this would occur if the U is at "yellow" or higher risk levels).

2. Strong encouragement of students to reduce their presence on campus as much as possible, taking advantage of tele options to meet with faculty, advisors, etc.

3. Providing faculty with the option to design their course (online or various hybrid options) in a way that they think will be most effective while still meeting University distancing and other criteria. 

4. Encouraging faculty faculty to move classes online if they can do so effectively.

5. Mandatory mask use in classrooms and public spaces.

6. Transparency in all decision making, which considers diverse perspectives. 

I confess pessimism about the plans currently being put forth by Utah, Arizona State and other universities, although I hope that ultimately that pessimism is unjustified. 

Storms in Spades

Active weather with lightning, thunder, strong winds, and hail continues today.  Below are a couple of radar images from this morning showing strong storms in the Wasatch Front area.

We had a round of strong winds here in the upper Aves this morning and also some small hail that was a bit larger than pea sized.

So far, the big winner in the hail category appears to be Plain City.  A viewer tweeted this photo to Chase Thomason of KUTV2 news. 

Keep an eye on the sky as the thunderstorm threat continues today.

Saturday, June 6, 2020

Quite a Saturday Ahead

Mother Nature will be throwing an active day at us today and she is already bringing the goods.

I was up early this morning as I have quite a bit of yardwork to do today, but the weather is not cooperating.  Showers and thunderstorms extend from the Oquirrhs into eastern Utah at 1300 UTC (0700 MDT). 

These storms have been moving northward, leaving a trial of lightning strikes from I-70 to just north of Evanston.  The highest lightning-strike densities are well east of I-15, but there have also been a few in the Salt Lake Valley and adjoining Wasatch Mountains. 

Source:  Lightning in hour ending at 0709 MDT.
Today will be the epitome of if you don't like the weather, wait 5 minutes.  The latest HRRR shows periods of showers and thunderstorms in the southerly flow ahead of the front (which we are currently in) and with the approach and passage of the front around 1800 MDT.  I've selected a few forecast hours below to illustrate both the active and break periods over the Salt Lake Valley.  Keep in mind that the chaotic nature of thunderstorms means that you can't count on precision in these forecasts and should keep an eye to the sky throughout the day.  

In addition to rain, we've had some strong winds in the area.  My house has done quite a bit of shaking at times.  Weather observations from a citizen observer in the upper aves show a peak gust of 68 mph yesterday at about 1900 MDT and then a gust this morning of 54 mph at about 0700 MDT.  

Source: MesoWest
Since yesterday, peak gusts reported to MesoWest include 78 mph on the Salt Flats, 70 mph at the Moab Airport, 68 mph in the upper Aves, 64 mph in Magna, 62 mph in Parley's Canyon, 61 mph near Point of the Mountain, and 52 mph at the Salt Lake City Airport.  The list of stations reporting gusts over 50 mph is remarkably long, so strong gusts were reported in many areas.

Stay safe out there.  When thunder roars, head indoors.

Friday, June 5, 2020

Good Storm Chasing Weather?

Being a severe-weather aficionado in Utah is a bit like being a powder skier in Oklahoma.  The pickings are slim. 

However, unlike powder skiing in Oklahoma, which is essentially non-existent, there are a few days a year where something exciting might happen around here. 

The Storm Prediction Center puts parts of Utah in the marginal severe thunderstorm risk category over the next two forecast periods. 

A severe thunderstorm is one with wind gusts of 58 mph, hail at least an inch in diameter, and/or a tornado.  Marginal risk means that the storms could be spotty and limited in duration and/or intensity.  However, this is Utah and marginal is about the highest you see.

The SPC convective outlook discussion highlights that increasing moisture, strengthening wind shear, and other environmental characteristics should be favorable for isolated strong storms, potentially with strong winds and hail.  The NWS Forecast office in Salt Lake City has also issued a flash-flood watch for portions of central and eastern Utah. 

While I mentioned the storm chasing potential, the reality is that severe weather is hazardous weather.  Be careful out there and monitor forecasts, watches, and warnings.

Thursday, June 4, 2020

Big Changes Are Coming

Major changes are on tap weatherwise over the next several days.

Today looks to be hot and tomorrow (Friday) even hotter as a closed low off the coast of Baja California begins to fill and lift into the southwest United States.  This leads to strong southerly flow across the Great Basin with temperature climbing and fire weather conditions deteriorating. 

NWS forecast highs for the Salt Lake City Airport are 91˚F today and 96˚F tomorrow.  Disgusting.

Saturday's forecast is crapshootish as the former closed low continues to fill and moves across Utah and a much deeper trough approaches from the west.  Right now, the GFS has the former moving across Utah in the morning and producing showers and thunderstorms producing the heaviest precipitation over central and eastern Utah.

The situation for northern Utah is pretty complicated due to the weak atmospheric stability, a front approaching from the west, and a moisture dryslot.  My guess is that there will be some decent weather on Saturday, but the threat of some showers and thunderstorms is real, so keep an eye on the radar, another on the sky, and adjust as needed. 

Right now, the GFS has the frontal band approaching Salt Lake City late Saturday and over Salt Lake City by 0300 UTC 7 June (9 PM MDT Saturday). 

That will be followed by cooler weather with periods of showers and possible some thunder as the pattern will be markedly springlike.  The NWS forecast high for Monday is 59˚F, nearly 40˚F lower than their forecast for Friday. 

If you are recreating this weekend, be aware that changes are coming and consult NWS forecasts.  Expect some evolution in forecast details (e.g., the timing of the front or periods of thunderstorms or showers), but the threats for critical fire weather conditions Friday and thunderstorms and heavy rain that could produce flash floods in southern and eastern Utah are real, as well as the overall cooling trend.  NWS flashflood information available at