Early next week, the sweltering heat dome will move eastward from the Lower 48, baking the Ohio Valley, Midwest, Southeast and Mid-Atlantic. Highs could be 10 to 15 degrees above normal, with readings peaking in the upper 90s and heat indices exceeding 100.
Excessive heat: Temperatures above 100 swell from Texas to California
Records could be under threat in many major cities, with conditions that could prove downright dangerous for the elderly, homeless and other vulnerable populations.
The National Weather Service issued excessive warnings or heat advisories for more than 30 million desert southwest residents across California’s Central Valley through the weekend.
High in the desert southwest
Phoenix and Las Vegas are under excessive heat warnings through Sunday, with temperatures expected to break records.
“Typically, we usually see the first excessive heat warning in early to mid-June, so that in itself isn’t incredibly abnormal, but temperatures will be approaching record highs,” said National meteorologist Jenn Varian. Weather Service. office in Las Vegas.
Record highs are forecast for Thursday and Friday in Vegas – the number to beat Thursday is 108 degrees, and a high of 109 is expected. That surpasses the record set in 1996. Saturday’s predicted high of 109 degrees would tie a record. The average high in Las Vegas at this time of year is around 100 degrees.
“The excessive heat is here. No change in forecast thinking,” the Las Vegas Weather Service office wrote in its online forecast discussion. “Temperatures will remain elevated at dangerous levels.”
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The heat affecting Las Vegas actually covers most of the southwest, encompassing southern and western Arizona, most of southern California, including the Inland Empire and deserts, and the densely populated San Joaquin Valley in California.
Phoenix, a city of nearly 1.7 million, is expected to hit 110 degrees Thursday, 113 Friday, 114 Saturday and 113 degrees Sunday. That should break records on Thursday and Saturday and tie on a Friday. It hit 110 degrees for the first time this year on Wednesday.
“The risk of high to very high heat will prevail throughout the region through Sunday,” wrote the Weather Service for Phoenix, where an excessive heat warning is in effect through Sunday.
The Arizona Department of Environmental Quality has also issued an air quality alert, which means ground-level ozone could reach dangerous levels. Ozone production near the surface is catalyzed by excessive heat and can cause breathing difficulties. The agency is urging those using gas-powered equipment to wait until late in the day.
In Las Vegas and Phoenix, as well as many other communities in the Southwest, the biggest concern isn’t the triple-digit daytime highs – it’s the unusually warm nighttime lows, which may not drop below the 80s in many places.
“The overnight lows are the worst part of it in general,” Varian said. “If we just have highs approaching record highs and it gets colder overnight, we probably won’t issue an excessive heat warning. But for people who are homeless, who may not have housing or who try to save a dime with air conditioning, their body can’t cool down at night.That’s when the impacts start.
Maricopa County has opened dozens of cooling shelters in the Phoenix metro, though the vast majority are only open during the day. A site shared by the department allows residents to search for the nearest location using their address.
In Las Vegas, the Salvation Army has received funding from Clark County to reopen the daytime cooling shelter that had been closed in 2021 because of the coronavirus pandemic. A few more chills shelters were also opening.
Excessive heat warnings are in effect through tonight for northern parts of California’s Central Valley, where readings in the valleys and foothills are expected to be between 100 and 107 degrees today. It is likely that the alerts will be extended or reissued in the coming days.
“In addition to hot temperatures during the day, there will be little heat relief overnight,” the Hanford, Calif., weather service warned.
Sacramento is expected to hit 101 degrees Thursday afternoon, 105 Friday and 102 Saturday before returning to the upper 80s on Sunday. That could tie a record on Thursday.
⚠️Dangerous heat is forecast Friday for much of the valley and foothills. Warm daytime temperatures with warm overnight lows will create a high risk of heat-related impacts for the general population. Visit https://t.co/ZNcH9hrV5K for heat preparation tips. 🌡️ #CAwx pic.twitter.com/iBLtolKclb
— NWS Sacramento (@NWSSacramento) June 8, 2022
The heat advisories cover the rest of the Central Valley south to where the excessive heat warning begins in Southern California but also reaches west towards the Bay Area. Downtown San Francisco is not under any type of alert, but Friday’s expected high of 81 degrees is about nine degrees above average.
In Death Valley, Calif., the high is expected to hit 120 degrees on Friday and 121 degrees on Saturday — tough daily records, with overnight lows at the Furnace Creek Visitor Center in the lower 90s. Nearby needles should be between 113 and 117 degrees, just a hair’s breadth from the records.
Texas and Central United States
Tens of millions of people in the Lone Star State are also expected to face sweltering temperatures. Unlike its counterparts to the west, however, the heat that will grip Southeast Texas, including Houston and Galveston and the Interstate 10 corridor, is not dry heat.
“The combination of near-record high temperatures and high dew points will produce increasingly dangerous heat index values between 100 and 106 degrees today,” the Houston Weather Service wrote in a special weather release. The bureau predicts heat indices above 108 between Friday and Sunday, which could lead it to issue a heat advisory.
“Heat-related illnesses and deaths are preventable, and all heat-related safety precautions should be taken even if there is no heat advisory in effect!” he wrote.
A very hot weekend is expected with inland highs above 100 degrees while coastal areas rise into the 90s. Heat Index values above 105 are expected. Continue to take heat safety precautions to protect yourself from these dangerous conditions. #houwx #txwx pic.twitter.com/Jhq4ZROHCl
— NWS Houston (@NWSHouston) June 9, 2022
Houston could hit 100 degrees any day through Sunday before returning to the mid-90s.
“Yes, Houston is hot in the summer, but usually not as hot in June,” headlined an article for SpaceCityWeather.coma Houston weather website.
Further north, Dallas is expected to be around 102 degrees Thursday and Friday before catching a 105 on Saturday and 103 on Sunday. With the heat dome lingering overhead, the Metroplex is likely to remain elevated above 100 through the middle of next week.
Austin will be between 100 and 105 every day, as will San Antonio, and no immediate relief is in sight.
The heat is entirely due to a high pressure dome, which brings clear skies and hot, dry, descending air. The jet stream diverts north of the high, taking all the weather and storms with it. This allows for abundant sunlight, allowing sunlight to pour in and heat the ground unhindered.
The science of heated domes and how drought and climate change are making them worse
This heat dome will be centered over the Four Corners region on Saturday, but is expected to move east over the plains on Sunday and reach the eastern United States by Tuesday. Thereafter, it may persist, bringing widespread highs of 10 to 15 degrees above normal.
It is likely to usher in what could be the first major East Coast heat wave of the season.
Human-caused climate change amplifies heat waves like this, making them more intense and longer lasting.