Colder Weather Coming Later This Month

COLD SNAP COMING NEXT WEEK…

Meteorologist Jeff Jamison blog post earlier today spawned more questions.  In particular the National Weather Service placed on their website today this graphic showing the Arctic Oscillation.

The Arctic Oscillation Index is a measure of the pressure around the Arctic and the temperature of the Stratosphere.  You can read more here.

In the winter, the Arctic Oscillation gives us a sense of when cold air will move into the central and eastern part of the United States.  A Positive Number, which is when the line is above zero in the graph above, means the cold Arctic air remains bottled up into the Arctic Circle.  When the Arctic Oscillation goes into Negative range, that is when the cold Arctic air spreads south.  This is looking more likely by the end of next week in the following week.  How far south that cold air makes it will be determined by the weather pattern across the United States.  But it can be assumed that if the Arctic Oscillation stays negative for an extended period of time, we will have the potential for some cold snaps later this month into February.  Colder than what we have seen so far this winter!