Brief Flirtation with Nuclear Summer

The first 8 days of July are in the record books and as anticipated, they were hot by 20th century standards, but not too bad by early 21st century standards.

The average temperature for those 8 days was 78.1˚F, which is a bit higher than the average July temperature in the 20th century (77˚F), but quite a bit lower than the average July from 2010–2018 (81.6˚F).  That period also clocks in as the 3rd coolest since 2010, behind 2010 and 2019.  

Source: NOAA Regional Climate Centers

So, hot for for your grandparents, but cool for your kids. 

It looks, however, like we will see a trend toward misery through Saturday, although the worst of the heat may be short lived. 

This morning, the GFS shows us in fairly weak west-southwesterly large-scale flow with three major large-scale flow features at 500-mb.  The first is a trough over the Gulf of Alaska.  The second is a weaker trough just off the Pacific northwest coast.  And the third is a weak ridge over Texas.

Through Saturday, the trough just off the Pacific Northwest coast progresses downstream across the northwest US, while the Gulf of Alaska trough amplifies.  Meanwhile, over the southwest US, the ridge that was previously over Texas migrates westward and amplifies.  By Saturday morning, if is centered over New Mexico. 

During this period, all of Utah will see increasing temperatures.  NWS forecast highs for the Salt Lake City International Airport today, Friday, and Saturday are 93, 96, and 98 respectively. 

That flirtation with what I like to call "nuclear summer", the hottest and most miserable part of the year for heat and sun intolerant snow lovers like me, looks like it will moderate in northern Utah, however, as the Gulf of Alaska trough progresses downstream into the Pacific Northwest and the ridge weakens through Monday. 

Thus, highs relax to 97 and 93 on Sunday and Monday, respectively.  Additionally, the forecast highs for Tuesday and Wednesday in the wake of the trough are 90 and 88.  A quick look at the ECMWF shows similar trends. 

Thus Saturday looks to be the warmest of the next five.  There is some risk we will make a run toward 100.  I dread thinking about it, but take some solace that we should cool off a bit early next week.