WASHINGTON — Lately, the jet stream isn’t playing by the rules. Scientists say that big river of air high above Earth that dictates much of the weather for the Northern Hemisphere has been unusually erratic the past few years.
They blame it for everything from snowstorms in May to the path of Superstorm Sandy.
And last week, it was responsible for downpours that led to historic floods in Alberta, Canada, as well as record-breaking heat in parts of Alaska, experts say. The town of McGrath hit 94. Just a few weeks earlier, the same spot was 15 degrees.