From Sunglasses to Shivers: Why the Weather Has Been Giving You Whiplash - NBC4 Washington

From Sunglasses to Shivers: Why the Weather Has Been Giving You Whiplash

Weekend weather forecast from the teens to the to the 60s



    From Sunglasses to Shivers: Why the Weather Has Been Giving You Whiplash
    A tale of two live shots.

    Skiing on a Thursday, but riding your bike while getting a tan by Sunday? It's all leaving us with one question: What is up with this weather?

    Storm Team4 Meteorologist Sheena Parveen explained why we're seeing such dramatic dips and spikes.

    The normal high temperature for this time of year is 45 degrees, yet we've been seeing unseasonably warm temperatures, with record highs in the 70s. But Thursday, temps plummeted, with a wind chill making it feel like the 20s.

    A big part of this is due to the North Atlantic Oscillation (NAO). Besides the fact that this phrase will make you sound really smart if you whipped it out in the break room, there's another reason why you should remember the NAO.

    Meteorologists look to the NAO to predict when arctic air in Canada is going to spill down into the Northeast, Parveen said.

    Think moody teenager. When the NAO is in a positive phase, that cold air stays locked up in Canada. When it's in a negative phase, we see it reach down to us.

    Sometimes we can get some short spurts of a negative phase coming down, giving us a couple of cold days, and then we're right back into a positive phase, keeping the air locked into Canada.

    Which brings us to what's been happening lately: There's has been no reason, meteorologically, for the cold air to spill back down out of Canada. Our friendly neighbors in the south have been giving us plenty of warm air moving up the coast, allowing for T-shirt weather Tuesday and Wednesday.

    That cold air hasn't been coming down much from Canada, which is why those snow lovers are still mad.

    Parveen describes it as an invisible wall, holding the arctic air back -- and the wall has been pretty strong lately. In a negative phase, that wall weakens and that cold air drops down. But our moody teenager has been feeling really peppy lately, so we've been mostly getting unseasonably warm temperatures.

    Parveen doesn't see much of a negative phase happening in the next 10 days either. There's a chance we'll get a few shots of cold air, mostly in the mornings, but it's looking like middle-of-February temperatures will be a little above average.