It’s February, but you wouldn’t guess it by Washington’s 80-degree forecast on Thursday, which the National Weather Service (NWS) noted could “feel more like June than February.”

Just four hours north, New York City is expected to be slightly warmer than normal, but more than 30 degrees cooler than Washington.

What’s happening with this wide variation in temperatures up the East Coast?

Southeastern US sees unusually warm temperatures

A view of uptown Manhattan from the Empire State Building is seen in New York City on Tuesday, May 18, 2021. (AP Photo/Ted Shaffrey)

Washington normally sees a high of 50 degrees Fahrenheit and a low of 33 degrees during this time of year. However, temperatures are expected to rise into the high 50s overnight on Wednesday and could reach up to 80 degrees on Thursday.

It also will be warmer than normal in New York City, but it won’t feel like the middle of summer.

The expected high of 49 degrees in New York is above the average high temperature for this time of year, which is 44 degrees. But that’s much less of a jump above average than what D.C. is expected to see.

Richard Bann, a meteorologist at NWS’s Weather Prediction Center, said the unseasonably high temperature in D.C. is the result of warm air entrenched over the southeastern United States.

Across the Mid-Atlantic and Ohio Valley, temperatures could be more than 40 degrees above average, with potentially record-breaking highs, according to the Weather Prediction Center.

Temperature gradient helping drive massive winter storm

A car slowly travels down a road after a second round of snow passed through northern Minnesota Thursday, Dec. 15, 2022, in Duluth, Minn. (Holden Law/Associated Press)

The NWS describes the warm temperatures expected in D.C. and parts of the mid-Atlantic as “significantly anomalous.”

They also are connected to the massive winter storm making headlines as it drops feet of snow in the Midwest and upper Plains, said Bann.

Minnesota, South Dakota, Wisconsin and Michigan are expected to get one to two feet of snow this week, with potentially record-breaking levels of snowfall forecast for southern Minnesota.

Schools and government offices closed across the swath of northern states on Wednesday in preparation for the storm.

The warm air over the southeastern U.S. coupled with extreme cold weather in northern Minnesota and North Dakota is helping drive this winter storm, Bann said.

“It thrives on large differences in temperature over a broad area,” he said. “If everything’s really kind of uniform, there really is nothing to work with.”

“Warm air is being drawn northward ahead of the system and cold air is being pulled southward behind it,” Bann added. “So, it takes advantage of having that big temperature contrast.”

But it won’t be warmer than normal everywhere in eastern states either on Thursday.

Temperatures in the far northern city of Caribou, Maine, are expected to fall below normal, with a high of 12 degrees on Thursday, as the winter storm moves toward New England.