The main purpose of this ongoing blog will be to track planetary extreme, or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉
Main Topic: Heatwave Chevron to Persist Well into August
Dear Diary. This last week of July has been advertised as the hottest week of the year so far for the U.S. due to what I’ve dubbed as Heatwave Chevron, but what comes thereafter? Will most of us continue to roast, or is there some relief on the horizon going into August? On this installment of the Extreme Temperature Diary, I’ll try to answer these questions.
First, let’s look at where we are with extreme heat as of this Thursday. Yesterday Heatwave Chevron was ramping up across the Midwest and Northeast looking at temperatures and the extent of National Weather Service advisories:
Today we are seeing areas of heat advisories getting expanded with large areas of heat warnings appearing on the following NWS chart. This chart would be typical for a borderline CAT3/4 heatwave using my criteria:
The heat dome in association with Heatwave Chevron is immense, stretching from coast to coast:
Note how far north the 588-decamter height contour is on the above Pivotal Weather chart. Usually, life threatening heat occurs above this level of heat in the atmosphere, but a 588-decameter heat dome is quite common during the summer. Heat domes getting above 597 decameters are rare across the United States but are getting more common as climate change starts to ramp up. We see that the center of Heatwave Chevron is located over New Mexico and is at about 597 decameters. The center of Heatwave Chevron has stayed near New Mexico for weeks at about 597 decameters, which is why Pheonix has seen temperatures as high as 119°F. Now its heat done extends all the way to the Northeast coast.
Here are today’s forecast maxes, which are well above seasonal averages for most locations outside of the Pacific Northwest:
There is some good news for the Northeast. The jet stream will buckle over the weekend allowing a trough and associated cold front to cool that region as well as Northern portions of the Midwest by Sunday and Monday:
There won’t be much cooling outside of the Northeast through the first week of August since the center of Heatwave Chevron won’t fall much below 597 decameters and will have a tendency to move eastward onto the Plains:
Though hotter than average, the above 500 millibar chart is typical for early August. Since the center of Heatwave Chevron will finally move eastward out of the Soutwest, this will allow monsoon moisture to move into that area of the country bringing some cooling relief to cities like Pheonix. I expect their historically long streak of 110°F or better days to finally end sometime next week.
The center of Heatwave Chevron may actually build and move westward again late next week. Should the following GFS model verify, all-time records will be threatened across the Southwest again, but we are looking at a timeframe outside of my 240-hour rule of thumb for model reliability, so any forecast going into the second week of August is quite sketchy. Also, should the following weather pattern develop, there will be cooling relief coming to the Midwest, Plains and Southeast:
Here is President Biden’s response to this excessive heat:
Of course, we’ll be keeping an eye on models to see how Heatwave Chevron progresses. Suffice it to write, the thing will unfortunately be with us for a long time to come.
Here are some other “ET’s” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks, as well as any extreme precipitation reports:
Here is more climate and news from Thursday:
(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)