This week, a heat dome will bring stifling temperatures and uncomfortable humidity to millions of people in the United States.
The heat will be especially dangerous this weekend across large swaths of Nebraska, Illinois, Wisconsin, and Iowa, with forecasters warning of extreme temperatures.
This will be many people’s first taste of true summer weather from the Midwest to the East Coast, according to Tom Kines, a meteorologist at AccuWeather, a private weather company.
“A lot of those people have been asking, where is summer? “Well, buckle up, because it’s coming,” Kines warned. According to Kines, humid conditions will make places with temperatures above 90 degrees Fahrenheit (30 degrees Celsius) feel up to 20 degrees hotter.
Heat dome forming
A heat dome forms when a large area of high pressure in the upper atmosphere acts as a reservoir, trapping heat and humidity, according to Ricky Castro, a National Weather Service meteorologist from Illinois.
According to the NWS Weather Prediction Center, daytime temperatures will be in the 90s Fahrenheit (30s Celsius), with overnight temperatures only dropping to the mid-70s Fahrenheit (mid-20s Celsius) from the Great Lakes to the East Coast during the heat wave, which is expected to last until next week.
According to Jacob Asherman, a meteorologist with the Weather Prediction Center, moisture blown northward from the Gulf of Mexico is fueling the muggy weather. This influx of Gulf moisture is fairly common in late spring and summer, he explained.
The heat will continue to spread into next week. The weather service predicts that Denver may reach 100°F (38°C) on Friday. On Sunday, temperatures in Chicago could reach 96 degrees (36°C). On Tuesday, Washington, D.C. could reach a high of 99°F (37°C), while New York Central Park could reach 96°F (36°C).
Several Midwest states could experience dangerous temperature impacts over the weekend, according to a weather service risk assessment ranging from zero to four. On Saturday, parts of Nebraska and Kansas will be in the highest category on the scale, posing health risks to anyone who does not have adequate cooling or hydration. On Sunday, Iowa, Wisconsin, Missouri, and Illinois will all be rated as category 4.
High humidity makes it difficult to cool down.
According to the weather service, humidity is the amount of water vapor in the air, and heat index is how the temperature feels when the humidity outside is taken into account.
When humans sweat, it cools the body by absorbing and removing heat as it evaporates from the skin. On humid days, the air becomes saturated with water, making it difficult for sweat to evaporate. Hot and humid days can be dangerous because the body is unable to cool itself, exacerbate pre-existing health conditions, and even cause heat stroke.
According to the NWS, ways to cool down during extreme heat include minimizing direct sun exposure, wearing loose, light-colored clothing, staying hydrated, and spending time in air-conditioned spaces.
Some parts of the United States, such as Phoenix, Arizona, are famously hot but not muggy. Phoenix and surrounding desert regions experience so-called “dry heat” as a result of their distance from large bodies of water, mountains that block moist air masses, and weather patterns that bring little precipitation.
Sweat evaporates faster in dry climates than in humid ones. According to Johns Hopkins University and Johns Hopkins Health System, this can be dangerous because it is easy to underestimate your level of dehydration.
Even the crops “sweat”.
In places like Iowa, crops can have an impact on humidity during the summer months. Plants respond to hot weather, and some people in the Midwest are familiar with “corn sweat,” which occurs when crops move water to their leaves and other surfaces so it can evaporate, according to Ohio State University.
Ryan Marquardt, a farmer in Madison County, Iowa, stated that corn sweat is “not as bad as a sauna, but it definitely has a sauna effect.” “It’s humid in there (the cornfield), so you’ll sweat.”
