Just in time for the start of summer on June 20, a heat wave is expected to scorch a large section of the United States, forecasters said.
“The hottest weather of the season so far will build over the central United States later this week with widespread highs in the 90s and some 100-degree readings in store from the Rockies to the Mississippi Valley,” said AccuWeather meteorologist Alex Sosnowski in a June 15 online forecast.
A few locations could approach or top 100 degrees during the heat wave, including Denver, which only happens twice a year on average, according to Weather.com meteorologist Jonathan Erdman, who added that “New York City and Philadelphia could also flirt with the century mark during the peak of the heat wave next week.”
According to the Weather Prediction Center, the heat wave will begin Friday, June 20 across the Plains then expand over the weekend across portions of the Midwest and Great Lakes. The heat is then likely to shift and persist across the Ohio Valley, Northeast and Mid-Atlantic late this weekend through next week.
In fact, the center is warning that a rare “high risk” of extreme heat is anticipated early next week across portions of the Ohio Valley as well as from New England south into the mid-Atlantic.
‘Dangerous conditions’ possible
The vast zone of heat with significant humidity levels will make for dangerous conditions, and care should be taken not to overdo any activity in the midday and afternoon hours, Sosnowski said.
Indeed, daily high temperatures are forecast to be well into the 90s and warm overnight temperatures only dropping into the mid-70s from the Great Lakes to the East Coast, which will offer little to no relief to those without adequate or reliable cooling, the Weather Prediction Center said. “The first significant heat wave of the year can pose more danger,” the center warned.
As the heat builds, limit outdoor activity, stay hydrated, and ensure access to air conditioning and other cooling areas.
“Heat exhaustion and heat stroke can strike even physically fit individuals in the prime of their lives,” said Sosnowski.
Much of the Midwest will see “major” heat risk from Friday June 20 to Sunday June 22.
Heat waves incoming
For man y areas from the Midwest to the central Appalachians, mid-Atlantic, and perhaps parts of New England, the first heat waves of the year will bring the highest temperatures of the year so far.
“Detroit has peaked at 88 degrees so far this year; New York City has only reached 87 and Cincinnati and Pittsburgh only mustering 86,” AccuWeather senior meteorologist Chad Merrill said. “While locations such as Washington, D.C., Baltimore and Philadelphia have exceeded 90 and Boston has achieved 89 so far, the upcoming conditions will bring the hottest weather of the summer to much of the Ohio Valley, Great Lakes and the I-95 corridor.”
In Chicago, the weather service said “hot and humid conditions are expected as surface temperatures climb into the 90s and heat indices into the 100s.”
It was 30 years ago this summer that Chicago endured one of its worst heat waves on record, when hundreds of people died due to the extreme temperatures.
Heat will persist at night, forecasters warned. “Don’t expect much relief at night with widespread low temperatures in the 70s for most of the latter third of June,” Merrill added.
Why will it be so so hot? Blame the ‘heat dome.’
This heat wave will be triggered by a change in the jet stream pattern, said Erdman in an online forecast.
“Specifically a strong bubble of high pressure aloft known as a heat dome will develop over the eastern U.S. Sinking air near the center of this heat dome suppresses clouds, allowing the intense sunshine this time of year to heat the ground and air above it,” Erdman said.
Southerly and southwesterly winds will also tap hot and humid air from the South into the Midwest and Northeast, he said.
This article originally appeared on USA TODAY: A ‘Heat dome’ is forecast to bring scorching temperatures to the US.
