WASHINGTON – It’s the dog days of summer, but don’t tell that to Mother Nature. A polar vortex look-alike is headed toward the Eastern U.S. and will bring unseasonable temperatures across the area early next week.
The blast of cold air is expected to move in from the Gulf of Alaska, similar to the Polar Vortex that swept the area in January.
“When you put the maps side-by-side, it does have a similar look to what we saw over the wintertime. Just remember though, air masses are different temperatures even if they come from the same place,” says ABC7 Meteorologist Brian van de Graaff.
By Monday or Tuesday, he predicts the temperatures could drop more than 20 degrees below normal, but won’t come close to the single-digit record-breakers felt in January.
Around the D.C. metro area, temperatures could reach the 70s during the day, 50s at night and upper 40s in the mountains.
“Our models look out several days and we get updates several times per day. When we start seeing a pattern emerging, we get the idea that this might be happening. It does look like there will be a pretty big push of some cooler air but I think it can modify somewhat as it moves in here,” he says.
There’s a possibility that storms will impact the region.
“One of the things we’re concerned about around here with something that strong, that big of a contrast headed our way, we actually could have the outbreak of some strong weather before that cool air moves in here,” van de Graaff says.
Residents in the upper Midwest will feel the biggest impact. They are bracing for winter-like low temperatures, which could dip into the 40s.
There are some mixed feelings within the meteorology community about whether this event can be considered a true polar vortex.
“It’s interesting. It’s the same source region of cold air. So yes it’s similar, but there are varying opinions on whether or not you call it a polar vortex in the middle of summer. It is cooler air but it’s all relative because we’re talking about cooler air in the summer not cooler air in the dead of winter.”
Van de Graaff says the typhoon in Japan could be partly responsible.
“It’s surging a big plume of warm and humid air northward up into the Pacific which is then kind of dislodging and leading to more of a trough pattern in Alaska and over the central United States. That’s going to allow that cool air to sink in here.”