Extreme Temperature Diary- Thursday July 17th, 2025/Main Topic: The Rise of Heatwave Pemex – Guy On Climate
Dear Diary. It has been about a week since we had a major heatwave across a portion of the U.S. In this day and age of climate change, we knew that this reprieve couldn’t last for long. Heatwave Texaco is barely hanging on across western Washington as a CAT1 today. The heat dome responsible for this system has been in the process of breaking down this week. A new heat dome has been building in the East in response to a trough quelling Texaco in the West.
Already this week we have dangerous conditions across the East Coast and some heat warnings and advisories across the Mid-South. Using my system, this heatwave is pegged as a dangerous CAT2 and is well on its way to being a major CAT3. The next oil company name I will use one the system gets to be a CAT3 is Pemex, named for the state-run Mexican oil company.
Unlike with Texaco, the heat dome in association with Pemex will be long lasting and will probably spread through much of the nation the next two weeks:
We know that the above two panels will verify with the heat done growing looking at model ensembles:
There is a good chance that Pemex will grow into a monstrous historic CAT4 towards the end of the month:
We will see if we eventually have a 597+ or God forbid 600+ decameter heat dome closer to August. In the meantime, many will be sweltering in a more typical heatwave due to about a 594-596 decameter ridge centered over the Mid-South that will produce some dangerous conditions as far north as the southern Midwest and Northeast.
Follow along for updates on Pemex at @climateguyw and ?@climateguyw.bsky.social?.
Here are more “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:
78 U.S. cities experienced at least a week of days at or above a Climate Shift Index (CSI) of 2 during June 2025... (meaning climate change made temperatures those days at least 2x as likely).
Our monthly U.S. attribution report by @climatecentral.org (June): www.climatecentral.org/report/month...
— Zack Labe (@zacklabe.com) 2025-07-16T20:39:43.745Z
Reflecting on average temperatures over the last 3 months - find your location...
🟥 warmer than average
🟦 colder than average
Dataset described in doi.org/10.1175/BAMS...
— Zack Labe (@zacklabe.com) 2025-07-16T12:40:12.129Z
Carbon dioxide (CO₂) averaged about 430 ppm in June 2025
10 years ago June averaged about 403 ppm
Preliminary data from @noaa.gov: gml.noaa.gov/ccgg/trends/
— Zack Labe (@zacklabe.com) 2025-07-15T23:56:37.920Z
Methane (CH₄) is a potent greenhouse gas. Here are the latest monthly observations... 🧪⚒️
March 2025 - 1934.49 ppb
March 2024 - 1927.58 ppb
+ Data: gml.noaa.gov/ccgg/trends_...
+ More info on methane budget and trends: essd.copernicus.org/articles/17/...
— Zack Labe (@zacklabe.com) 2025-07-16T17:30:05.448Z
I have a goal of adding one new visual per day at zacklabe.com/united-state..., and this one was particularly eye-opening - sea surface temperatures averaged by year for the Caribbean... 🌀🌊
Data from @noaa.gov OISSTv2.1 (downloads.psl.noaa.gov/Datasets/noa...).
— Zack Labe (@zacklabe.com) 2025-07-17T01:58:28.576Z
Now showing average June #Arctic sea ice volume since the year 1901...
A high resolution version of this graphic can be downloaded at zacklabe.com/arctic-sea-i.... Comparison between PIOMAS-20C and PIOMAS datasets available at doi.org/10.1175/JCLI....
— Zack Labe (@zacklabe.com) 2025-07-17T11:15:12.181Z
Last month was the 3rd hottest June on record globally...
It was also separately the 6th warmest June for global land areas and the 3rd warmest for global ocean areas.
Data provided by @noaa.gov NOAAGlobalTemp v6.0.0 (www.ncei.noaa.gov/products/lan...)
— Zack Labe (@zacklabe.com) 2025-07-14T21:14:06.674Z
Now that NOAA is no longer tracking billion-dollar weather disasters, rely on insurance broker Gallagher Re, who just released their list for the first half of 2025. So far, we are near the 10-year average. The CA wildfires ($65 billion) were the 8th-costliest weather disaster in world history.
— Dr. Jeff Masters (@drjeffmasters.bsky.social) 2025-07-16T11:08:54.625Z
This has been the second most humid summer in DC on record (since 1945) based on the number of hours with dew points over 70 degrees or the level considered GROSS.
— Capital Weather Gang (@capitalweather.bsky.social) 2025-07-17T15:54:11.024Z
Another day. Another flash flood—this time across New York and New Jersey.
Record rainfall in a short span overwhelmed streets, subways, and neighborhoods.
• Here's what happened (via @nytimes.com): www.nytimes.com/live/2025/07...
• 🧵below is how climate change played a role ⤵️
— Climate Central (@climatecentral.org) 2025-07-15T14:24:46.404Z
