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 Builds Again in the Southwest This Weekend
Dear Diary. Far worse than a visiting family member than won’t go home, historic CAT4 Heatwave Chevron won’t abate or leave the south-central states and Southwest. Here was the state of the system on Friday:
The heat dome in association with Heatwave Chevron is large but not that atypical for early August as of this morning:
What has made Heatwave Chevron historic is its longevity over the area, producing more record hest and drought conditions from early July until now.
On Sunday Heatwave Chevron’s heat dome will retrograde towards the west a bit and grow to a near 598 decameter monster. On Sunday and Monday look for Phoenix to have a max above 115°F in record territory. Residents there are distraught at this point from this summer’s heat, I know.
Later next week the heat dome will weaken but hug the Gulf Coast eastward into Florida, Note that the bulk of the U.S. will see refreshing below average 500 millibar heights, so Heatwave Chevron is not expected to move north from the southern states:
Here is the latest Washington Post article describing the unrelenting heat from Heatwave Chevron:
Prolonged heat wave baking Texas and the South is expanding West
A slew of record highs are expected over the next week near the Gulf Coast, in Texas and into the Desert Southwest
Updated August 4, 2023 at 10:15 a.m. EDT|Published August 3, 2023 at 12:43 p.m. EDT
Forecast peak heat indexes Friday across Texas and the South from the National Weather Service. (WeatherBell)
Record-challenging heat is baking the south central United States and, over the coming days, is forecast to expand to the west bringing a resurgence of hot weather to Phoenix, which just endured the hottest month ever observed in a U.S. city.
The National Weather Service forecasts dozens of calendar day heat records — from the Gulf Coast to Arizona — over the next week, for both scorching afternoons and sultry nights. Several records for the entire month of August could also be in jeopardy. Records will be most numerous in Texas, where several locations are enduring historically long streaks of 100-degree weather.
On Thursday, Austin logged its 27th day in a row at or above 100, tying the previous record from 2011. It’s forecast to see highs of around 105 for the next week.
As of Friday, parts of seven states in the South — Texas, Oklahoma, Kansas, Missouri, Arkansas, Louisiana, and Mississippi — are under excessive heat warnings for highs of 100 to 105 degrees and heat indexes as high as 120 degrees. Heat warnings also cover Phoenix and much of southern Arizona into southeast California.
How Bad is the heat risk near you?
(The Washington Post)
We’re tracking dangerous heat waves across the United States daily. Look up your city to see extreme heat risks near you.
About 60 million people are under heat alerts across the Lower 48, including residents of Phoenix; Dallas; Oklahoma City; Wichita; Little Rock; Shreveport, La.; Jackson, Miss.; Mobile, Ala.; and Memphis.
Corpus Christi, Tex., and New Orleans are forecast to lead major cities in heat index values Friday, topping out at 113 degrees, according to The Washington Post’s extreme heat tracker. On Thursday, New Orleans set an Aug. 3 record high of 98 with a peak heat index of 108. On Monday, the temperature hit 101, matching a July record.
While the hottest readings will dance around the southern United States over the coming days, punishing levels of heat and humidity will persist into next week.
Heat warnings and advisories indicate conditions that can lead to illness or even death from exposure, especially for vulnerable groups including older adults without access to air conditioning, the homeless and outdoors workers. The extended spell of heat only exacerbates concerns, given limited nighttime cooling and the accumulation of heat stress.
State of the heat dome
The highest temperatures outside the Desert Southwest on Friday will focus on a region from Arizona to Louisiana, where more than a dozen record highs are at risk. Cities that could set records include Tucson, El Paso, Austin, San Antonio, Houston, Jackson and Mobile.
Much of Arkansas, Louisiana, Oklahoma and Texas will see high temperatures of 100 to 105 degrees Friday, which are about 10 to 15 degrees above normal and it will feel another 5 to 10 degrees hotter factoring in humidity.
Into the weekend, the footprint of exceptional heat will expand to the west and east as the heat dome swells. By Sunday, the dome will be centered around southern parts of Arizona and New Mexico, near the border with Mexico, squashing rainfall chances and intensifying the heat in the Southwest.
By now, Arizona and surrounding locations are usually in the summer monsoon season, which brings increased cloudiness, rain and cooler temperatures to the region. But this year, the moisture-laden air has been largely absent despite some recent rain that has helped firefighting efforts in the California desert and southern Nevada, where the York Fire, California’s largest blaze of 2023, is ongoing.
Through the weekend, high temperatures stay near and above 100 degrees from southern Oklahoma to central Mississippi and to the south. The Weather Service is forecasting heat indexes as high as 122 degrees in west-central Mississippi.
Near the heart of the heat dome, El Paso is expected to flirt with calendar day record highs five of the next seven days, with readings as high as 108 degrees predicted. Tucson is similarly on track to threaten records six out of the next seven days. Phoenix will probably run to and past 115 degrees by Saturday, which would match a calendar day record, and see highs hovering around 115 well into next week.
Notable heat numbers
Weather historian Don Sutherland compiled a list of cities that may achieve an August record high during this next flare-up of heat. Among them is Phoenix, where the monthly record high is 117 degrees. It could come close to that between Saturday and Wednesday. Other locations, including Albuquerque and Del Rio, may have an even higher chance of setting monthly high temperature records.
In addition to Austin’s record 27 consecutive days of highs of at least 100 degrees, several other notable streaks are ongoing in Texas:
- College Station has seen 26 100-degree days in a row, tied for second most on record; the number to beat is 30 from 1998.
- Dallas has an ongoing 100-degree streak of 11 days — which ranks among its top 20 longest.
- Houston has seen five 100-degree days in a row and is forecast to see highs near the century mark for the next week.
Heat risk forecast for next Wednesday. (NWS)
No sign of a break
The forecast for the future remains atypically hot in many of the same locations, which have contended with sweltering heat since late June.
There is some potential for the heat dome to drift southward into Mexico for a time during the second half of next week, but any relief would probably be short-lived.
The most reliable forecasts two weeks into the future suggest nearly wall-to-wall above normal temperatures from Texas to southern California. The heat may even try to expand northward into the western United States again by mid-August.
Weather models suggest more of the same mid-month. (weatherbell.com)
Jason Samenow contributed to this report.
More on extreme heat
Our warming climate: In July,Phoenix set a national heat wave record for the hottest month ever in a U.S. city. Heat waves are ramping up the global burning of fossil fuels, asJuly will be Earth’s hottest month on record.Here’s why the sweltering heat wave isn’t moving anytime soon. Use our tracker to see your city’s extreme heat risk. Take a look at what extreme heat does to the human body.
How to stay safe: It’s better to prepare for extreme heat before you’re in it. Here’s our guide to bracing for a heat wave, tips for staying cool even if you don’t have air conditioning, and what to know about animal safety during extreme heat. Traveling during a heat wave isn’t ideal, but here’s what to do if you are.
Understanding the science: Sprawling zones of high pressure called heat domes fuel heat waves. Here’s how they work. You can also read more about the link between weather disasters and climate change, and how leaders in the U.S. and Europe are responding to heat.
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 brand-new July 2023 climatology:
Here is more climate and news from Saturday:
(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.)