If you feel as though it has jumped straight to summer, you’re not imagining things. A major episode of sweltering heat, which has already toasted Texas, is about to swallow much of the central and eastern Lower 48. Temperatures in the mid-90s will surge as far north as the Canadian border by Saturday, running 25 degrees or more above average.
Amarillo, Tex., reached 101 degrees on Tuesday, breaking a record that has stood for nearly a century. In Dallas, the past 11 days have hovered at or above 90 degrees, the earliest such streak on record.
The relentless heat in Texas prompted the Electric Reliability Council of Texas (ERCOT), the state’s power grid operator, to encourage residents last weekend to set their thermostats to 78 degrees during the afternoon to conserve energy. But in a statement issued Wednesday, ERCOT wrote that it expects to have sufficient generating capacity to serve peak demands through the summer.
This Texas heat is next poised to expand northeastward.
More than 170 million Americans — about half of the U.S. population — are expected to see temperatures top 90 degrees in the next several days. Atlanta, Charlotte, Knoxville, Tenn., Washington, Baltimore and Philadelphia are all expected to see their first instance of 90-degree weather of the year by Friday.
Some parts of the Carolinas could even see triple digits. The National Weather Service is forecasting a high of 100 near Fayetteville, N.C., both Thursday and Friday.
The same overarching weather pattern is bringing a dearth of storminess and continued drought to the central states while bolstering the risk of windy thunderstorms across parts of the Great Lakes and New England.
A developing heat dome
Contributing to the hefty heat is the overarching setup of the nation’s weather. It has been characterized by zonal, or west to east, flow as of late. That has meant few jet stream meanderings and reduced severe thunderstorm activity in the Plains, compared with normal activity.
It has also allowed heat to begin to gather over the Southern states without any crashing cold fronts or interruptions that could disturb its progress.
Now a heat dome, or sprawling sphere of high pressure at the mid levels of the atmosphere, is taking shape over the East. Anchored over New England, the heat dome will bring clearing skies, sinking air and dry conditions. It will also truck in toasty air out of the Southwestern United States.
Meanwhile, a counterclockwise-spinning zone of low pressure passing through southern Quebec and Ontario will strengthen south-southwesterly winds. That’ll amplify the heat even further before a cold front reaches the Eastern Seaboard at the beginning of next week.
Heat gathers over South
On Wednesday, temperatures were expected to soar well into the lower 100s across much of the Lone Star State and southwest Oklahoma. Temperatures in Abilene, Tex., could jump to 107, a far cry from the city’s average mid-May high of 87.
The city already set records on May 7 and 8 when it hit 107 degrees, the earliest in the year on record for that to occur. It has already set a record for the most 100-degree days during the month of May.
Nearby Hamlin, Tex., could snag a 108-degree high on Wednesday, and Throckmorton, about 155 miles west-northwest of the Dallas-Fort Worth area, could make it to 106 degrees. A heat advisory is in effect for Central Texas, the National Weather Service warning that “hot temperatures may cause heat illnesses to occur.”
Thursday could be equally hot in Texas Hill Country before a subtle relaxation of highs by 3 or 4 degrees by Friday. A more meaningful cool-down will come into the weekend, when highs in the 80s are expected.
Dallas, meanwhile, is set to reach the mid- to upper 90s on Wednesday, Thursday and Friday. That may flirt with the current-standing records of 97 degrees for Wednesday and Thursday, but Friday’s current-standing record of 95 should be easier to beat. It has seen its warmest start to May on record.
In Oklahoma City, where the average high this time of year is barely 80 degrees, highs Wednesday and Thursday will climb to about 96 degrees. That could tie or break daily records.
Highs in the 90s are likely across all the Southern states through Friday.
East Coast heat to ramp up
By Thursday, a concentrated filament of more intense heat will begin working up the East Coast. Georgia and the Carolinas will see highs in the mid- to upper 90s, perhaps approaching 100 degrees, on Thursday, with readings a degree or two higher by Friday. Even southern Ohio could see highs in the lower 90s on Friday.
A high of about 92 degrees is expected in the nation’s capital Friday, its first 90-degree high of the year. By Saturday, the mercury could surge to 95 degrees in Washington, which would match the record from 1934. Factoring in the humidity, it could feel like 100 degrees or even a little higher.
Lower to mid-90s make it to New York City and Boston on Saturday as slightly cooler conditions take hold of the Midwest with highs around 75.
By Sunday, an approaching cold front will squeeze the heat to the immediate Atlantic coastline, but millions of Americans along the Interstate 95 corridor could near 90 degrees once again.
The early-season slice of summer is connected to human-caused climate change, which favors earlier, longer and more intense heat waves. As Earth’s temperatures continue to rise, the weather will skew toward more heat extremes, posing growing public health risks, particularly to vulnerable groups.
Jason Samenow contributed to this report.