Wasatch Weather Weenies

 Abstract No. Introduction At the Salt Lake City International Airport, only 0.26 inches of rain fell in July, compared to an average of 0.72.  In August, it was 0.10 compared to an average of 0.76.  September?  Only 0.19 compared to an average of 1.33.  Will it ever rain again? Data and Methods I looked at the Global Ensemble Forecast System (GEFS) forecasts for the next week and extrapolated them 7.6 billion years forward to when the Sun will exhaust its fuel and expand as a red giant. Results No GEFS members produce precipitation at the Salt Lake City International Airport through 1200 UTC 8 October.   Source: NCEP Since there's no precipitation forecast for the next week, extrapolation suggests it will never rain in Salt Lake City ever again.   Conclusions It will never rain again in Salt Lake City.  This forecast, however, is contingent on a number of assumptions.  In particular, we assume that the forecast for the next week is...

 Our fall semester like no other is now at the 1/3 point.  The University of Utah is now going into a two-week "circuit breaker" during which classes will be fully online.  This circuit breaker has been planned for some time, long before the most recent spike in Utah coronavirus cases began and was developed, based on modeling, to reduce COVID infections on campus and provide a pause for the Vice Presidential Debate, scheduled for October 7. I am teaching entirely online this semester, but have gone to campus a few times, including several days of in-office working while my power was out.  With a majority of classes online, it's pretty quiet, with little of the energy and excitement that you find on a large campus during the school year.  My online courses are taught live.  It was a major effort to retool classes that I've taught in person for 25 years.  Here's a short list: I learned canvas and had to move all my course materials to that format. ...

 This year's three-month July-September period is going to go down as one of the hottest and driest on record. For the period from July 1 through September 26, 2020 is tied with 2017 for the 2nd warmest on record with an average temperature of 78.7˚F, behind only 2013 (80.1˚F).  Source: NOAA Regional Climate Centers With four days left, I haven't done the calculus to see where we're likely to end up, but it will be up there, although it won't be a record (we have no chance of getting 2013, which finished the full July to September period with an average temperature of 79.2˚F). The odds of precipitation through the end of the month, however, are vanishingly small, so the 0.55" we've received since July 1 is going to be the tally.  That rates as the 8th driest such period on record.   Source: NOAA Regional Climate Centers The driest July to September was in 1879 with only 0.14 inches. Looking regionally, the we see that nearly the entire southwest has been below ...

There is a narrative that often appears after "natural" disasters (natural in quotes since some are quite unnatural or have a strong anthropogenic component) that our society needs to change, and that is saying that the disaster was unexpected or came out of nowhere.   An example of this is provided by the tweet below saying that 2020 has been the year of the "unexpected." 2020 has been the year of the unexpected. As we continue to stay safe & healthy, we want you to know resources are available. This week's #SLC News has windstorm recovery updates & next steps, the final countdown to the #2020Census , voting info & more, https://t.co/hzQm2GXDVH . — SLCgov (@SLCgov) September 23, 2020 Although we have suffered a series of challenges, none of these were really unexpected.  A short list would include the pandemic, earthquake, fires/smoke, and windstorm.  Perhaps I've forgotten something as the year's been a blur. The coronavirus pandemic is...

  "When I’m sometimes asked ‘When will there be enough (women on the Supreme Court)?’ and my answer is: ‘When there are nine.’ People are shocked. But there’d been nine men, and nobody’s ever raised a question about that.” - Ruth Bader Ginsburg After the passing of Ruth Bader Ginsburg on Friday, I found myself choked up.  It is the tough loss of a great woman who meant a great deal to many, including my young daughter as she has grown into a young woman.   Ginsburg was an advocate for gender equality, an area in which the "STEM" disciplines (Science, Technology, Engineering, and Mathematics) has long lagged.  In high school, I did not have a single woman as a math or science teacher.  As an undergraduate student, I did not have a single woman as a math or science professor.  As a graduate student, I did not have a single woman as a math or science professor.  And, when I joined the faculty of the College of Mines and Earth Sciences at the Univer...

" You can always count on Americans to do the right thing — after they've tried everything else. " – Winston Churchill I've always liked that Winston Churchill quote and I've used it often to try and explain America to my international friends.  It usually results in a good, disarming laugh that enables us to compare and contrast cultures and political systems. What concerns me today is whether or not we can still count on the first half of that quote: America doing the right thing.  We face many challenges in which we've either tried everything else or have failed to accept what must be done, and yet we still are not doing the right thing.   Let's use the western wildfires as an example.  The growing and multifaceted threats of climate change, forest (mis)management, development in the urban–wildland interface, inadequate community or infrastructure preparedness, and human negligence (e.g., target shooting and other human fire starts) have been recognized...

Summer won't quit as we've had highs in the low 90s the past two days.  However, with the early sunset and long nights, I'll call the heat manageable as we haven't even thought of switching on the A/C as it's cooled off nicely overnight.  Last night the low at the airport was 60˚F, 32˚F lower than yesterday's high of 92˚F.  Wonderful sleeping weather. If you can make it through this week, I'm pleased to report that the models are advertising that a cold front and upper-level trough will bring cooler air for the weekend.  The GFS forecast valid 0900 UTC 19 September (0300 MDT Saturday) shows the cold front moving through northern Utah with even a hint of rain.   I'm not overly excited about that as most ensemble members are generating less than 0.1" and only a few members of the often too wet Canadian ensemble are generating more, but anything would be welcome.   Really, a weekend of heavy rain would be great.  Not only could we use it, but it...

Although Utah was smacked by a severe downslope windstorm, cutting power for 170,000 (with 5,500 still powerless), we should perhaps feel fortunate as others are facing much more dire consequences. This morning's satellite imagery is about as ominous as it gets.  Smoke from western wildfires has spread across much of the continental Unites States following both northern and southern trajectories.   We're in relatively clear air at the moment in northern Utah, although southern Utah is better.  Meanwhile, slow moving Tropical Storm Sally looms off the Gulf Coast, will likely intensify into a hurricane, and is expected to bring storm surge, flooding, and other impacts.   Source: CIRA Purple Air sensors show much of California, Oregon, and Washington is experiencing unhealthy air quality, with many areas hazardous.  Across the southern US, moderate air quality readings extend at least all the way to Texas due to smoke.   Source: purpleair.com I'...

The windstorm of 8 September featured a remarkable coverage of strong winds both along the Wasatch Front but also westward from the base of the Wasatch Range.  Although there was certainly an important downslope wind component to the event, with the strongest winds observed at the base of the Wasatch Mountains, it's important to recognize that the event was more than just a downslope wind event. Before looking at what happened on 8 September, lets' take a look back at another event that occurred on 1 December 2011.  You may recall this event as it produced a 101 mph gust in Centerville, Utah and quite a bit of damage in the Centerville and Farmington area.  Power outages affecting 50,000 customers occurred along the northern Wasatch Front through North Ogden, but were somewhat more limited in the Salt Lake Valley, althouth there were some in Millcreek, Murray/Holladay, and Midvale. Power Outages from the 1 December 2011 event. Source: Salt Lake Tribune Analyses of the eve...

 The events unfolding across the western United States this week are remarkable and include heavy snowfall along the Front Range of Colorado, severe downslope winds in Utah, and extreme fire behavior in the Pacific states.  We'll get to some of the details of what happened in those areas eventually, but to start, let's talk about why this is such an exceptional event.   To do this, we must take a global perspective as everything starts with the highly anomalous large scale flow that has developed over the past few days.  A critical player in all of this appears to be Typhoon Julian, which on August 30th was near the Philippines but on track to move northward and interact with the mid-latitude jet stream (see red arrow below).   Whenever there's a tropical cyclone recurving into the midlatitudes and interacting with the jet stream, I go on high alert.  Although this doesn't happen all the time, such interactions often lead to a rapid amplification ...

I don't know about you, but the anticipation for colder air and some exciting weather is high today.   And, the push of the cold front through Montana, Idaho, and Wyoming is simply fascinating.   Let's first get a quick look at where things stand at 16:30 UTC (10:30 MDT).  As indicated by the MesoWest observations below, northerly winds and the leading edge of the cold air has surged through Montana and is now pushing through north-central Wyoming, having just reached Riverton.  Further West, northerlies have surged down the Madison Valley and other valleys in southwest Montana and are just cresting the Continental Divide.  Apologies for the ugly analysis, but it gets the job done.   Basically, the shallow, leading edge of the cold air is surrounding the high terrain in and around Yellowstone, although that region will be "submerged" eventually.   MesoWest observations at 1030 MDT 7 Sep 2020 The 4-hour HRRR forecast valid at 1900 UT...

The colors are really starting to pop in lower City Creek Canyon.  Sadly, the photo below from this morning doesn't do it justice.  They seem especially pretty right now as the scrub oak begins to turn.   Unbelievable satellite imagery this morning with thick smoke over much of California, Nevada and Oregon.   Some of it is moving downstream into Idaho and Utah and you could see it moving in at mountain crest level from about 10 to 11:30 this morning.  Note in the photo below how the central and southern Oquirrhs around the Kennecott mine are obscured.   My guess is that the surface heating hasn't warmed things up enough for the near-surface atmosphere to mix with the smoke layer aloft yet.  Guessing we will see that change during the day today, with PM2.5 concentrations rising in the valley as the day goes on. The overshooting top of the Creek Fire near Fresno is very apparent in the satellite imagery above, which was taken at 15:31 UTC...

 It's hard not to get excited about the first major cold surge of the season after the blistering heat we've suffered through the last several weeks.  Mother Nature is going to make us suffer this weekend, but MAJOR change is coming by Tuesday.   The loop below shows the GFS forecast 500-mb heights (black lines) and 925-mb temperatures (colored lines) from 1200 UTC (0600 MDT) this morning through 1200 UTC (0600 MDT) Tuesday.  There are two major large-scale circulation changes that occur at upper levels.  First, the ridge from hell that has dominated our weather for so long weakens and shifts upstream.  Second, the upper-level pattern becomes much more strongly amplified, meaning that the ridges and troughs get stronger, resulting in a more wave like pattern, which by Tuesday morning features a high-amplitude ridge over the northeast Pacific and a deep trough digging into the Rocky Mountain region.  With that trough comes one hell of an airmass c...

No surprise here.  August 2020 goes down as the hottest on record with an average temperature of 83.0˚F.  Thanks to cooler weather the last two days of the month, this tops August 2013 by only 0.3˚F.   Source: NOAA Regional Climate Centers There have been 9 years with an average temperature at or above 80˚F, all since 2003 except for August 1994.  Prior to August 1994, there had never been an August with an average temperature above 78.5˚F.  Recent Augusts have been exceptional. For the year to date, the average temperature was 56.7˚F, which slots in as the 7th warmest on record.  2018 produced the warmest January - August temperature at 60.1˚F.   How do I feel about having meteorological summer behind us.  It's good to have it in the rear-view mirror.