The heat dome scorching Texas and other parts of the South for the last couple of weeks has resulted in more than a dozen heat-related deaths, and the record-setting heat is expected to move eastward. Though it won’t be as bad in Boston, temperatures are expected to rise in the coming week.
Here is what you need to know:
What is a heat dome?
A heat dome is when a pocket of heat is trapped over an area because of a buildup of high pressure that doesn’t move for a week or more. The heat dome can span multiple states, as is currently happening in the South.
In the United States, our weather moves west to east, pushed by a river of wind in the atmosphere referred to as the jet stream. But when the jet stream has north-south dips, some air can get trapped in place, according to Rachel Cleetus, policy director for the Climate and Energy Program at the Union of Concerned Scientists, and Erika Spanger-Siegfried, lead analyst for the climate campaign in the Climate and Energy Program at UCS.
“In this case, the jet stream has developed a significant northward loop over the lower 48 states ... causing the heat dome over much of the southern states,” they wrote in a statement to the Globe.
How long will the heat dome last?
Projections from the National Oceanic and Atmospheric Association show the heat continuing through the end of the coming week. The heat dome is expected to settle over the Southeast, and temperatures in Texas are finally beginning to decline.
How dangerous is the heat?
With the heat index reaching up to 121 degrees in some areas of Texas, the state’s heat-related death toll has reached 13. The heat can be especially dangerous for the elderly and those with preexisting conditions, according to Cleetus and Spanger-Siegfried.
“The vulnerability that exists across our nation to extreme heat — with millions living in poverty, living urban heat islands, unhoused, working outdoors, lacking access to cooling, etc. — means that each heat wave poses serious threats to health, wellbeing, lives and livelihoods,” they wrote.
Residents in Texas were asked to voluntarily reduce their energy usage during evening hours as the electric grid strains under the rapidly increasing power demand from consumers.
Extreme heat also worsens ground-level ozone levels, leading to poorer air quality that could impact those with respiratory problems.
Should we be worried here in Boston?
The temperatures here are unlikely to reach the triple digits, but the heat index could reach 85 degrees to 90 degrees by the end of next week.
Even though it won’t be as hot as in the South, many of our buildings are not built to withstand such heat and lack air conditioning. Urban areas can face heightened risk because paved areas absorb heat. High heat can be especially grueling for vulnerable populations like the elderly, the very young, outdoor workers, athletes, unhoused people, and those with preexisting conditions. This is worse in lower-income neighborhoods without greenery or cooling infrastructure to bring down the heat.
Is climate change making things worse?
It’s still an active area of research, but these extreme climate events will become more frequent as the climate warms, according to Michael Rawlins, associate director of the Climate System Research Center at University of Massachusetts Amherst. The irregular dips in the jet stream have already been associated with other recent climate events like the Canadian wildfires.
How can I prepare?
“We’re nearing the hottest time of the year, which is typically a few weeks after the summer solstice,” Rawlins wrote in a statement to the Globe. “Always a good idea to keep an eye on the weather forecast.”
Cleetus and Spanger-Siegfried recommend staying indoors during the hottest parts of the day, or take breaks in the shade. Go to cooling centers if you don’t have air conditioning at home. Stay hydrated, and check in on neighbors who are vulnerable. Employers should follow public health guidance to protect their employees from the heat.