Wasatch Weather Weenies

After living through the hell of Seattle, I finally found pleasant weather yesterday in Ketchikan, Alaska, where we are visiting family. The weather today was perfect.  High of 70ish with sunshine and a good breeze.  It's rare, but when the weather here is nice, its a great place to be.   I have been reflecting on the heat of the past few weeks.  June in Salt Lake City was ridiculous.  7 days of triple digits and a mean temperature that will easily set a new record.  Through yesterday, the average temperature for the month was 80.1˚F.  The next highest is 77.5.   Source: NOAA Regional Climate Centers Then, how does one wrap their head around the Northwest US/Southwest Canada heat wave?  I can't.  I still can't fathom a high in Lytton, British Columbia of 121˚F.  Even in celsius it sounds awful.  49.6˚C.  Unfathomable.  Reports are this is the highest temperature ever recorded north of 45˚ north (and I suspec...

Sunrise this morning over downtown Seattle I lived in Seattle from 1989 to 1995.  It was a great time in my life and I thoroughly enjoyed the mild climate, especially the cool, dry summers. In 1989, the all-time record maximum temperature at the Seattle-Tacoma International Airport, known as SeaTac, was 99˚F. and it was great to boast about the region's natural air conditioning. In 1994, they reached 100˚F for the first time.  Then in 2009, 103˚F.  Still, those were the only two days in the triple digits since record keeping began at SeaTac in 1945.   A few weeks ago, we committed to going up to Seattle for a few days to cool down, a prospect that seems laughable now.  We drove across the Cascades on Saturday and enjoyed a view of the great snow scoop in the sky, Mt. Rainier, from the top of Crystal Mountain. It looks innocent enough in pictures, but temperatures that afternoon reached 102˚F at SeaTac as we pulled into town.   The evening forecast...

A weak short-wave trough and moisture surge moving into northern Utah later today will bring cooler temperatures and a threat of a few showers and thunderstorms tomorrow.  The likelihood increases through tomorrow with isolated T-storms later today, scattered tonight, and showers likely tomorrow.   The NAM forecast valid at 1500 UTC (9 AM MDT) tomorrow morning shows the short wave trough and associated clouds and precipitation over central Utah. This isn't a major monsoon surge, so it won't be a drought buster, event if you happen to get a good downpour wherever you are.  The concerning part of the cool down is that while we will get some precipitation, there will also be dry thunderstorms, which are thunderstorms that produce lightning, but little to no precipitation.  Enjoy the modest cool down, but hope that we don't see many if any fire starts.   The extended model forecasts are putting an enormous ridge over the Pacific Northwest and southwest Can...

A lot of people have commented lately that it hasn't been cooling off at night.  Indeed, minimum temperatures have been rising in Salt Lake City and in many other regions.   Let's have a look at Salt Lake City.  National Weather Service observations of the average June minimum temperature since 1874 (2021 includes only the first 20 days) shows significant variability from year to year, which is a reflection of weather variability.   Source: http://xmacis.rcc-acis.org/ There is an abrupt drop that occurs, however, in 1928, after which the average temperature seems to be much lower than it was previously.  This drop is almost certainly due to the moving of the observing site from downtown Salt Lake City to the Salt Lake City Airport, which is not only lower and prone to colder overnight temperatures, but back in 1928 would have been in a highly undeveloped area.   After 1928, average minimum temperatures seemed to fluctuate around with lit...

  This blog post is brought to you by Panda Express, which along with the adjoining but depleted Union food court, appears to be the only place to eat on the University of Utah campus and provided me with the fortune above yesterday.   Forget that.   This June has been awful.  How awful?  Some statistics: Although we just went through the climatologically coolest first half of June, if the month ended today, it would still rate as the warmest on record at the Salt Lake City International Airport (KSLC) by 1.4˚F.   Likewise for Tooele.  So far 1.1˚F hotter than the hottest June on record (records back to 1896). The average temperature at KSLC for June 1-16, 78.9˚F would rank in the top 25% hottest Julys .  More on July in a minute. KSLC has had no measurable rain so far this month (they recorded a trace on June 5). But what about the future?  As it says at the gates of hell, Abandon Hope All Ye Who Enter Here .   The G...

A few days ago, a notice was hung on our door from Rocky Mountain Power that our power would be shut down tomorrow from 9 am to 3 pm.   Given that today we are in an excessive heat warning and tomorrow a heat advisory, with a forecast high of 97˚F, this seems like an incredibly foolish time to shut down power.  We have options to leave the house during that period, but I wonder about neighbors and the notice warns that "unexpected difficulties may extend the outage."   Although they claim that "poor weather may cause the work to be cancelled or postponed," this has not happened yet.  I checked with Rocky Mountain Power via Twitter last night and they are still planning on shutting down the power.  Their response..."sorry for the inconvenience." I hope they will reconsider this shutdown as it is both reckless and foolhardy to have it this week.  It's not like they don't have the ability to monitor and adapt to the weather.  They have done powe...

A three-alarm fire occurred last night in an office building in Sugarhouse.  Sixty firefighters fought the blaze, which stared around 2 AM and continued into the morning.  One firefighter was injured and we hope they have a speedy recovery. I observed the smoke plume during a morning hike in the foothills.  At 8 AM, the behavior of the smoke plume was strongly affected by the stable cold pool that forms overnight in the Salt Lake Valley.  The smoke rose perhaps a couple hundred meters before settling back down and being transported by the local flows, as illustrated below.   I've annotated several key features.  The heating of a fire results in warmer air than the surrounding airmass.  As a result, the air becomes positively buoyant and rises, resulting in an ascending smoke plume.  As it does so, it cools and, if the air is stable as is often the case in the morning near the Earth's surface, it will eventually reach a level where it has the ...

Next week looks hellish, with the National Weather Service currently predicting (as of 8:25 am Friday 11 June 2021) maximum temperatures for the Salt Lake City International Airport of 102˚F Monday, 103˚F Tuesday, 101˚F on Wednesday, and 100˚F on Thursday.  These are all near record highs for those dates. How are maximum temperature forecasts produced?  The exact approach may vary depending on your source, but here are the basics. Numerical weather prediction models form the backbone for weather forecasts.  These models solve the governing equations for the atmosphere, which are based on physical laws such as conservation of momentum, mass, and energy.  On example is the Global Forecast System, or GFS, which is the primary modeling system produced by the National Weather Service for medium-range forecasting. Forecast models like the GFS have revolutionized weather forecasting.  In the middle of the 20th century, weather forecasting was based almost entirely on p...

 Don't let today's cool weather fool you, this June has been and will continue to be a disaster meteorologically, further exacerbating extreme to exceptional drought and fire weather conditions across the State of Utah. In the previous post, we discussed the remarkable heat of the first 6 days of June.  Here's an update.  The average temperature at the Salt Lake City International Airport for the first 9 days of the month was an incredible 79.8˚F.  This is the warmest start to any June on record. Source: http://xmacis.rcc-acis.org/ Let's take a closer look at the graph above.  Until 2016, the highest average June 1-9 temperature was 73.6˚F (1977).  We were 6.2˚F warmer than that!  In Salt Lake City, the urban heat island may be a local contributor, but even Alta had an average June 1-9 temperature of 59.3˚F, which is its highest on record.  Ah but the records there are spottier and only go back to the early 1970s.  How about we look at T...

The start of June has, in my view, sucked meteorologically. High temperatures at the Salt Lake City Airport for the first six days of the month were 88, 91, 97, 100, 97, and 92.   This is off the charts hot.  The average maximum temperature for the 6-day period was 94.2˚F, 3.2˚F warmer than that of any prior year on record.  In fact, there are only two other such periods with an average maximum temparature above 90: 2016 (90.5˚F) and 2020 (91.0˚F).   Source: http://xmacis.rcc-acis.org/ Although there were a few thunderstorms around on Saturday, the airport received only a trace, so they haven't had measurable rain yet this month either.  With warmth continuing and wind on the rise, the National Weather Service has issued a red flag warning through late Wednesday for the Salt Lake Valley as well as much of the state of Utah. Source: NWS, 2:40 PM MDT 7 June 2021 The good news is that we should see significant cooling on Thursday.  The GFS forec...

The National Weather Service has issued an Excessive Heat Warning for the northern Wasatch Front, Salt Lake Valley, Utah Valley, and the Great SaltLake desert for noon Friday to 6 AM Saturday.  Below is the warning issued this (Thursday) morning at 3:24 AM. Below is the infographic from their page showing comparisons of forecast and record highs for today (Thursday) and tomorrow (Friday).  If we hit 100 tomorrow, it would be the earliest on record by a day.   When it comes to susceptibility to heat, there's a lot more going on than just temperatures.  All else being equal, early season heat tends to affect people more severely.  Overnight temperatures matter for individuals without access to air conditioning.  Exposure to the sun can be critical, and with a strong ridge in place and the summer solstice near, we will see near-maximum possible ultraviolet radiation intensity.   For some long-term context, below is a graph showing the dates of t...

For me, May was a delightful month.  I haven't had to run the air conditioning, the mountain biking has been delightful, and there have been new trails to explore in the Avenues foothills which have been green and full of wildflowers, although that is changing now. The numbers for temperature, precipitation and drought, however, are more sobering.  Officially at the Salt Lake City International Airport the average temperature for the month was 62.7˚F, making it the 19th warmest May since record keeping began in 1875.  Rainfall was only 0.65 inches, which was not exceptionally dry, but still below the average of 1.82 inches.  Spring precipitation can be spotty, so any one station can sometimes not be regionally representative.  However, a statewide analysis of precipitation shows nearly the entire state received below average precipitation, with the southwest exceptionally dry.   Source: NWS Advanced Hydrologic Prediction Service The combination of abov...