A stubborn and unrelenting dome of excessive heat and humidity is languishing over the Lower 48 for the third week in a row, bringing record temperatures and heat index values topping 110 degrees in some places. Heat advisories and excessive-heat warnings blanket the Upper Midwest, including Milwaukee and Detroit, a prelude to even more intense heat pushing into the South and Southeast.
More than 55 million Americans are predicted to face triple-digit highs this week, and overnight lows could remain in the upper 70s to lower 80s in some areas. That will contribute to heat stress that could be dangerous for vulnerable populations. The National Weather Service is calling the combination of heat and humidity “extreme” and “dangerous.”
The heat, which was swelling through the Plains and Upper Midwest on Monday and Tuesday, is predicted to peak in the South and Southeast between Wednesday and Saturday, when high temperature records could be threatened between Central Texas and the western Carolinas.
The spiking temperatures could brew fire weather concerns amid a developing “flash drought,” with scant rainfall anticipated to pose a problem for farmers.
The heat so far
The heat on Sunday and Monday was most intense over the center of the country, including Texas, the Plains and the Upper Midwest:
- In North Dakota, Fargo (101, tie) and Grand Forks (100) reached record highs on Sunday.
- In Texas, Houston (101), Victoria (101) and Galveston (97) reached record highs on Monday.
- In South Dakota, Sisseton reached a record high of 100 on Monday.
- In Minnesota, Minneapolis and St. Cloud reached record highs of 101 on Monday. It was the first time over 100 in Minneapolis since 2018.
Record-breaking heat to come
Hot weather expected today, with near record highs near 100. Peak PM heat indices to 105 degrees, especially over NW IL. Heat-related illnesses may develop in fewer than 30 minutes after strenuous outdoor activity. Visit https://t.co/VqX5dajoBR for heat safety. #ilwx #inwx pic.twitter.com/JyIGsXsvuS— NWS Chicago (@NWSChicago) June 21, 2022
The core of the heat was shifting south and east Tuesday, allowing the northern Plains to settle back into the 80s. However, nearly 35 million people are under heat advisories from Missouri to Michigan. Highs of 95 to 100 degrees are forecast from Chicago to Detroit.
Most of the Deep South, the South and the Mississippi Valley will peak on Tuesday at about three degrees warmer than Monday’s highs. Atlanta, Nashville, Birmingham, Ala., Huntsville, Ala., and Tupelo, Miss., are predicted to reach the upper 90s.
On Wednesday, the worst of the heat wafts into the Southeast, accompanied by stifling humidity. The most affected will be the Florida Panhandle, Alabama, South Carolina and especially Georgia. That’s where highs in a few locales could top 105 degrees, with heat indexes up to 110 to 115.
The hottest spots Wednesday in Georgia will be around Macon and Albany, both anticipated to hit 104 degrees. In Macon, that would beat the existing record of 101 degrees set in 1925. It would also match the 104-degree reading observed on June 15, which set a record as the highest temperature ever observed so early in the year. Albany will probably set a daily record, too.
In metropolitan Atlanta, home to about 6 million people, the high should peak at about 100 degrees Wednesday and Thursday. That would nab back-to-back records. While “Hotlanta” is accustomed to highs in the 90s, the city’s characteristic sultry humidity makes it tough to nick the century mark.
The same is true in Alabama, where 100-degree readings in Huntsville and Birmingham are in the cards. Dothan may heat up to 105 degrees Thursday. Mobile is expected to get to 103 degrees, beating a record of 101 set in 2009. That will also tie as the highest temperature for a point this early in the year.
Most of the Interstate 10 corridor will reach 100 degrees Wednesday and Thursday, including in Tallahassee, Gulfport-Biloxi, Miss., and Baton Rouge. In Tallahassee, the first day over 100 in more than 1,000 days is predicted for Wednesday.
“Thursday is shaping up to be the hottest day in quite some time thanks to the heat wave intensifying further,” wrote the National Weather Service office in Tallahassee. “We are looking at high temperatures easily over 100 that will not only challenge daily records like Wednesday, but also all-time records!”
Record high temperatures will be in jeopardy from Wednesday through Friday. Will Tallahassee reach its all-time record of 105 degrees this week? It'll be close. Protect yourself from the upcoming extreme heat! 🌡️📈🥵🥵#GAwx #ALwx #FLwx pic.twitter.com/DVeoMYsIxD— NWS Tallahassee (@NWSTallahassee) June 21, 2022
Even New Orleans proper should hit 100 degrees Thursday and Friday, with about a 50-50 shot on Saturday and Sunday. That would net records Thursday and possibly Saturday.
Nashville will be in the upper 90s to near 100 during the stretch, and most of central and southern Arkansas should match. About two-thirds of Texas will be in the 102-to-106-degree range through the weekend and into early next week.
There are no immediate signs of the heat relenting. Instead, the National Weather Service Climate Prediction Center continues to forecast odds of above-average temperatures through the end of June and perhaps into July. Warm weather and high pressure “heat domes” are a staple of any summer, but their intensity and duration are exacerbated by human-induced climate change.
Fire danger surges
In addition to the raw heat and humidity, which will be taxing on the human body, the extreme heat will be problematic agriculturally. Two weeks without rainfall during the summertime can easily result in “flash drought,” or a sudden onset of unusually dry conditions that sap moisture from the ground. Regions beneath the quasi-stagnant heat dome, which brings sinking air and high temperatures, will be parched as the little remaining moisture in the soil evaporates.
Dry air behind yesterday's front = conducive conditions for fires to grow out of control mainly across NW GA thru metro ATL & across east-central GA. 🔥 Refer to your local burn permitting authorities whether you may burn outdoors & if you do burn, use extreme caution. ⚠️ #gawx pic.twitter.com/Rl8MUY0Ycu— NWS Atlanta (@NWSAtlanta) June 19, 2022
“Several hours of relative humidity at 25 percent or lower across (where 10-hour fuel moistures bottomed out yesterday at very low values of 4 to 6 percent) has prompted the issuance of a Fire Danger Statement for the afternoon and early evening,” wrote the National Weather Service office in Peachtree City, Ga., in an online forecast discussion.
Unfortunately, not a lick of rain is predicted anywhere in Georgia into next week.