It may soon be excruciatingly hot in North Texas, and a weather phenomenon called a “heat dome” will likely be to blame.
This heat dome started the week parked over the East Coast, breaking temperature records and resulting in numerous heat warnings. By mid-week, it’s expected to weaken some and slowly migrate west, which is forecast to incrementally drive up daily high temperatures in North Texas.
The system will firmly settle in over the region by the weekend, as well as some of Louisiana, Arkansas and Oklahoma. Heat advisories may be required as the heat index climbs.
What is a heat dome?
Record high temperatures — or very hot heat waves — can happen because of a heat dome that parks itself over a specific spot, according to AccuWeather.
A heat dome occurs when a high-pressure system is “stuck” in a certain location and holds the heat in. The atmosphere acts like a lid or cap over a region and traps in the hot ocean air, according to the National Oceanic and Atmospheric Administration.
Heat domes usually are linked to the behavior of the jet stream, a band of fast-moving atmospheric winds that generally flow west to east, William Gallus, professor of atmospheric science at Iowa State University, wrote for CBS News.
The jet stream typically meanders north, south and north again, and larger northern and southern movements make the winds move more slowly. When that slow-moving wind grinds to a halt, a heat dome occurs. The warm air sinks, which clears the skies, lowers the humidity and creates conditions for the sun to bake everything beneath it.
“A heat dome can have serious impacts on people, because the stagnant weather pattern that allows it to exist usually results in weak winds and an increase in humidity,” Gallus wrote. “Both factors make the heat feel worse — and become more dangerous — because the human body is not cooled as much by sweating.”
When a heat dome settles into a location, it takes a big push from the jet stream or another relatively strong system higher up in the atmosphere to dislodge it and release the heat.
Is this the same thing as a heat wave?
A heat dome and a heat wave are not the same thing, but they can occur simultaneously.
A heat wave is a period, typically longer than two days, of abnormally hot weather, according to the National Weather Service. Like heat domes, heat waves have the potential to cover a large region and expose a high number of people to hazardous heat, but do not have to be as large.
An abnormally high minimum temperature is also a crucial part of a heat wave, according to the World Meteorological Organization, as it can make it harder for people’s bodies to get relief from the heat.
