A Few Notes and Readings on the Heat Wave

I missed the heat event in Washington as I am out of the area. So I have no direct observations about the event. From afar it was really remarkable to follow this event as it developed. The weather models and projections were alarming and I will say it caused a level of concern for friends and family. I will also add that I have spent a fair bit of time in the Fraser River canyon and it is is painful to think about what has happened in Lytton.    

First of all, the weather prediction models were amazing. Models can be useful, but it really is remarkable when the models indicate something that has never happened and is an extremely rare event and the actual event happens as the models indicated.  

Phillippe Papin via twitter.com/pppapin/ lays out the antecedent event in the tropics and how the extreme heat would be generated. Note the post was June 23.  

There were a few statements made during the run up to and after the event that warrant repeating:

From the National Weather Service Seattle Office as the heat event was about to take place:  "As there is no previous occurrence of the event we're experiencing in the local climatological record, it is somewhat disconcerting to have no analogy to work with." --- National Weather Service, Seattle on June 27, 2021. 

This statement from Bob Henson and Jeff Masters clarifies what a big deal this heat event is: "Never in the century-plus history of world weather observation have so many all-time heat records fallen by such a large margin than in the past week’s historic heat wave in western North America. The only heat wave that compares is the great Dust Bowl heat wave of July 1936 in the U.S. Midwest and south-central Canada. But even that cannot compare to what happened in the Northwest U.S. and western Canada over the past week.", Bob Henson and Jeff Masters (worlds-most-extreme-heat-wave-in-modern-history)

Jeff Beradelli (Here) -- "To put climate extremes into perspective we measure against the average. The sigma is the standard deviation of a normal distribution of expected values. In this case the heat dome sigma max is 4.4 - that means it's outside of 99.99% of expected values or a 1/10,000+ chance.

 Bumbaco, Dello and Bond (2013) describe of how most heat waves develop in the Pacific Northwest and that description is consistent with this latest event. They note "Current research suggests that the frequency and duration of heat waves are expected to increase in much of the United States, and analysis of the heat events reveals that a significant, increasing trend in the frequency of the nighttime events is already occurring in the Pacific Northwest. A heat wave occurred in 2009 that set all-time-record maximum temperatures in many locations and ranked as the second strongest daytime event and the longest nighttime event in the record."

This chart shows that since the 2013 above described paper there have been a number of additional heat evets of 20+ above normal, and this event blew way past what took place in 2009.  

The attribution of this event to anthropogenic global warming (AGW) will be analyzed in detail. The attribution of AGW to extreme heat waves has been generally strong (Special Supplement to the Bulletin of the American Meteorological Society Vol. 102, No. 1, January 2021).