NEW YORK – A potent and nearly unprecedented weather phenomenon is enveloping large swathes of the United States this week, ensnaring regions under a formidable heat dome and causing temperatures to surge to triple digits in areas that haven’t experienced such extreme warmth in over a decade.
This heat wave poses a particular threat to major urban centers like Boston, New York, and Philadelphia since it arrives early in the summer before residents have acclimatized to such oppressive heat, according to several meteorologists. The heat dome, a high-pressure system currently settled over the eastern U.S., is trapping scorching air from the Southwest that has already made an uncomfortable passage through the Midwest.
A critical measurement indicating the intensity of this high-pressure system set a record on Monday, ranking as the third-highest on record for any date, contributing to what meteorologists are calling a “near historic” heat wave. Northeastern cities are expected to experience the peak of this heat on Tuesday.
“Imagine being in an air fryer; it’s going to be scorching hot,” said meteorologist Ryan Maue. “This is a challenging three-day period of dangerous heat that tests the resilience of city dwellers, particularly those most vulnerable to intense heat waves.”
A heat dome forms when a vast region of high pressure in the upper atmosphere serves as a barrier, trapping heat and moisture. A heat wave is characterized by sustained periods of heat, usually lasting three days or more, with unusually elevated temperatures.
Who Will Feel the Heat Most
About three-quarters of the nation’s population, translating to 245 million individuals, will endure temperatures reaching 90 degrees Fahrenheit (around 32 Celsius) or higher on Monday. On Tuesday, 33 million, or nearly 10% of the population, are expected to experience blistering temperatures of 100 degrees Fahrenheit (approximately 38 Celsius). The government’s heat health advisory has indicated the highest heat risk levels in vast stretches from Chicago to Pittsburgh and from North Carolina to New York.
Such extreme temperatures, enhanced by the heat index due to humidity, are expected in places where such heat is atypical. New York hasn’t experienced 100-degree days since 2011, and Philadelphia, set for consecutive days of triple-digit temperatures, hasn’t reached similar highs since 2012, according to Bernadette Woods Placky, chief meteorologist at Climate Central.
In Baltimore’s city center, residents sought refuge as temperatures soared into the high 90s by early Monday afternoon, with many heading to St. Vincent de Paul’s resource center to cool down. Nearby, the city’s iconic Broadway Market had to close early due to an air conditioning failure.
This intense heat prompted the cancellation of events in west Baltimore, noted Eric Davis Sr., who spends his days working at a local baseball field. “It’s too hot today to risk kids getting heat stroke,” he said.
National Oceanic and Atmospheric Administration (NOAA) meteorologist David Roth explained that the body requires time to adapt to summer heat, and this intense heat dome might come as a shock to many. “In some areas, temperatures could be 40 degrees warmer than last week, which is significant,” he said.
Climate Change’s Role
This searing heat is indicative of the Earth’s ongoing warming trend. Over the past 50 years, summers in the United States have become 2.4 degrees (1.3 degrees Celsius) warmer, as per NOAA data. According to Climate Central’s calculations, involving computer simulations, this heat wave is three times more probable due to human-induced climate change from the burning of fossil fuels.
A crucial consideration is how much humidity will amplify the heat’s discomfort and hazards.
Meteorologist Maue expects drier air, which could mean temperatures are a degree or two warmer than NOAA estimates, yet feels more bearable. However, other meteorologists are forecasting worse conditions: notably sticky, humid, and thus more perilous weather.
University of Oklahoma meteorologist Jason Furtado noted that humidity, driven by the wet late-spring conditions, will be notable. “The high-pressure area will promote a lot of evaporation from moist soils, significantly increasing heat indices,” he explained.
Woods Placky warns that dew points, a crucial humidity metric, will likely hit the 70s. This level is exceptionally tropical, with some areas approaching a dew point of 80, a condition that Woods Placky says makes it feel as though “you’re in a swimming pool” and “the atmosphere is absorbing you.”
Were this intense heat occurring later in the season, it might not be as dangerous due to acclimatization to summer warmth. However, this heat wave is arriving just days after the solstice, adding to its severity, as noted by Woods Placky and other experts.
“It’s going to be quite a shock to the system,” she said.