2/5/12 Happy National Weatherpersons Day!

Today is National Weatherpersons Day!   Why not thank your favorite meteorologist!     You can look up the info here.

A slight shift in the weather pattern over the past few days, will bring a change to the recent warm weather much of the eastern US has experienced over the past few months. At least for some northern States.  

The weather pattern has featured a cold pool of air over Alaska and Siberia and in fact over much of polar regions, which allowed a small dip in the jet stream over the Pacific Ocean.  This dip over the ocean allowed a flow of air to modify over the waters and flow right into the Continental US.  The jet stream which does act as the steering flow for weather systems also acts as a boundary between the warmer air masses and the winter air masses.  So with the jet being pushed south over the Pacific, it was allowed to rise over much of the US and the cold pool of air also was not allowed to drift eastward.

The weather pattern coming up for much of February has shifted greatly to what would be considered a more typical winter weather pattern with the pool of cold air (Known as the Polar Vortex) now situated over Hudson Bay.  The jet stream then can rise ( I over exaggerated the amplitude for effect) over the Pacific Ocean and then dip into the eastern 2/3 portion of the US.  This will allow the cold air to basically spin in place over Hudson Bay, ushering in waves and periods of cold air into the northern States. The mild air will be pushed further south and be allowed to build in the western US.

A feature also influencing our winter has been the North Atlantic Oscillation. We have been in a  Positive Phase since September (the last 2 winters have been in the Extreme Negative) For the month of February, it may shift some to a normal or near Negative phase.

A more indepth version of the polar vortex

and on the North Atlantic Oscillation

 Onto our Forecast:   Some fluctuations in temperature will happen this week, a cold front which pushed through last night, ushered in some colder air for the day on Sunday, however this front will move back through as a warm front overnight and allow our temperatures to rise into the 50s tomorrow!   Expect sunny weather until Thursday when a weak storm will pass to the south of New England and could bring a slight chance of a snow shower.