By Joseph D’Aleo, CCM

January will start out with some frigid air that will reach all the way down into the deep south. It will make some headlines but will not lock in. An old forecasting empirical rule was a big arctic outbreak is often followed by a big warm-up as the return flow behind the big high pressure pumps warm air north and east just as the northerly flow ahead had driven the cold air well south. It is all a part of the atmosphere bringing about compensation for the large temperature gradients between the polar regions and the tropics. Some record cold mornings will be followed by some warm records especially in places where no snowcover exists. That should last almost a week before the cold returns.

It is rare to have a wall-to-wall cold or warm winter. They start out cold and end warm or start warm and end cold or flip back and forth. La Nina years are especially fickle month-to-month. The weaker the La Nina the more unstable. This is a moderate La Nina.

Full size image here.

Meanwhile December has been snowy (with hemispheric snowcover above the 10 year average as seen on Dr. Bob Hart’s FSU snow page here). See the snow piles by my home in New Hampshire before last weekend’s rains. My mail box is in there somewhere.

Full size image here.

We will recap some of the record or near record snowfalls and cold December temperatures after the New Year and take a more detailed look ahead then.