Thursday August 8th… Dear Diary. The main purpose of this ongoing blog will be to track United States 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).😉
Is Another Significant Heat Wave Bubbling Up In The United States?
I’m going to put the word “significant” in quotes here since people from Texas eastward through the southern tier of states have already been dealing with “typical” but dangerous August heat for the better part of this week. Unlike hurricanes heat waves don’t get rankings, so they are very loosely defined and somewhat difficult to quantify. Here are current heat advisories:
My hometown of Atlanta earlier this afternoon had an above average reading of 93F. Wednesday Atlanta had a max of 95F and min of 75F, which was 5F above average on the low and high end of average temperatures. Yes it was hot in “Hotlanta,” a nickname for the city. Yet, maxes and mins in this southern heat zone as depicted on the Pivotal chart having advisories will need to rise about another 5F at least before there are widespread problems in Atlanta and elsewhere. Also, such a temperature regime would need to last many days. Potentially, could a prolonged ridge and associated heat wave pop up as we head through August? Let’s look at some basic meteorology to try to answer this question.
It’s interesting that the current level of heat is happening when there isn’t that much of a heat dome over the continental U.S. (Looking at the Northern Hemisphere view from the European Model) :
The ridge that has been parked over Texas will build, however, into next week:
We will need a complete weather pattern change to stabilize the wave/trough configuration of the above panel such that we see a prolonged heat wave in the eastern and southern states. Will this long wave pattern verify into the last week of August? The European model hints so, but there is a ton of room here for error:
As I have done so on many a prior post it’s time to look at ensembles since there is so much uncertainty with the long wave pattern:
Just about all individual model members of these PSU “spaghetti plots” keep a 594+ decameter ridge over most of the southern states as indicated by the brown countours, which would be plenty hot for an August heat wave. The average of the plots on the left side of the above chart indicates that the jet will be fairly flat or zonal across the CONUS, which usually doesn’t last long in any season. Big changes may occur by late August either squashing any heat via a strong front, or building more heat if systems dig into the Rockies.
It will take much more heat getting trapped under a stable ridge to see widespread numbers of record all-time temperatures than what we have seen thus far this summer, though. Thankfully, we are pretty far away from seeing enough heat in the atmosphere for widescale health threats across the United States.
In the very short range Friday looks like a hot, above average temperature day for much of the southern states:
There is more “temporary” good news. Models don’t hint at the Atlantic tropics awakening through next week. We’ll keep you posted on this also.
Here is more climate and weather 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.)
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Guy Walton- “The Climate Guy”