Comment As record temperatures scorch Europe, with temperatures reaching 115 degrees in Portugal, the state was just as scorching. Sixty million Americans could experience triple-digit temperatures in the coming days, with lows reaching highs of 115 degrees and heat index values topping 120 degrees. Dallas and Oklahoma City are forecast to reach at least 108 degrees Tuesday afternoon. Heat advisories and extreme heat warnings cover the plains, where the combination of record heat and tropical humidity will put dangerous stress on the human body for those unable to escape the heat. This poses a serious threat to the elderly, the homeless and others who do not have adequate access to cooling shelters. Europe floods in record heat wave as thousands flee wildfires “Extreme heat and humidity will greatly increase the potential for heat-related illness,” the National Weather Service wrote, “especially for those who work or participate in outdoor activities.” The heat is focused on the southern plains and south central United States, but it has already managed to deliver a record high of 107 degrees in Salt Lake City on Sunday. In Montana, Glasgow experienced one of the 10 hottest days on record at 108 degrees. An extended ridge of high pressure known as a heat dome is responsible for the high temperatures. It brings clear skies, sinking air and plenty of sunshine. It also diverts the jet stream north towards Canada, deflecting any large storm systems or severe weather. That’s why heat domes often cause drought. Tuesday is likely to be the hottest next week, although century highs will remain for the foreseeable future. Oklahoma City is expected to reach 109 degrees on Tuesday, its hottest since July 20, 2018. The Sooner state capital has reached 109 degrees only 19 times since 1890. “We had one day in 2018 where we got up to 109,” said Vivek Mahale, a meteorologist with the National Weather Service in Norman, Okla. “We’ll be around 104 tomorrow [Wednesday]but even so we will be 5 to 7 points above average for the rest of this week.” In southwest Oklahoma along the HE Bailey Turnpike, the high temperature is expected to top out around 112 degrees Tuesday afternoon. Since July 1912, this has happened only 20 times – making the heat a roughly once every five year event. It’s a similar story in Wichita Falls, just across the Red River in north central Texas, which is also showing a reading of 112 degrees. The extreme heat, locally topping 110 degrees, is bleeding further south into the Dallas-Fort Worth Metroplex, where DFW International Airport tied for its hottest day on Monday. The morning low of 86 degrees and afternoon high of 109 degrees averaged 97.5 degrees, matching the record set on August 3, 2011. That 86 degrees also tied a record warm low. Fort Worth’s Meacham International Airport soared to 110 degrees Monday. Dallas is projected to hit 109 again on Tuesday and 108 on Wednesday. So far this month, DFW has already had 14 days of 100 degrees or more. 🌡️Dangerous heat is expected on Tuesday with almost record temperatures. Forecast highs range from 106 to 113 °F. ⚠️Check out these heat safety tips and signs of heatstroke—remember, too much heat can be deadly! #okwx #texomawx pic.twitter.com/16o2UncEaV — NWS Norman (@NWSNorman) July 18, 2022 In addition to the magnitude of the heat, the duration is equally concerning. “I would say right now the longevity” is more impressive, Mahale said. “The biggest impact on people is how persistent he was.” The heat itself is unusual – about 5 to 10 degrees above average in places like Oklahoma and Kansas and up to 15 degrees above normal in the Lone Star State. Even Houston is expected to top out around 100 degrees every afternoon through at least early next week. In Austin, highs in the 102 to 106 degree range are expected through at least early next week. The same is true in San Antonio, Tulsa and Wichita. Even more problematic are overnight lows, which in many areas won’t drop below the mid-80s. High temperatures at night are a major contributor to heat-related deaths, as hot nights prevent the body from entering the nocturnal resting period. Highs above 100 degrees will also extend across the desert southwest. The sun is setting on an intense wildfire in Somervell County (SW of DFW). This fire produces a tall cumulus cloud (see its shadow on the east side). Fire releases heat and moisture and when there are unstable atmospheric conditions, these can develop into storms. #dfwwx #txwx pic.twitter.com/ueHaQsTqxE — NWS Fort Worth (@NWSFortWorth) July 19, 2022 In Southeast Texas and along the Gulf Coast, dew points near 70 — indicating the amount of tropical moisture in the air — will lead to heat indices approaching or exceeding 110 degrees. Further north and west over Interstate 35, comparatively less moisture will translate into weather concerns. Red flag warnings are in place for a wide swath of Texas and Oklahoma, where relative humidity may drop below 25 percent and winds may gust up to 30 mph. “A red flag warning means a dangerous combination of weather and dry vegetation is expected within 24 hours, favoring the rapid growth and spread of any wildfires,” the National Weather Service in Tulsa wrote. Several fires are already burning in the south-central plains. Those conditions could “contribute to extreme fire behavior,” the Weather Service in Norman said. More than half of Texas is experiencing a severe or peak “extreme” drought, according to the US Drought Observatory. “We haven’t had significant rainfall in a while,” Mahale said. “Many of our stations have not had at least 1/4 inch of rainfall for 30 to 40 days and have been isolated to only very scattered storms over the past month. As the vegetation dries, this makes it easier to heat the crops. You don’t have a lot of evapotranspiration and things dry out.”
