During the winter of 2010-11 we had a La Nina pattern settle in from December through late February, then it weakened some in the spring. Last year featured above average snowfall and slightly below normal temperatures from December through February. Well, La Nina has made a comeback, and it looks to be with us for much of the upcoming winter. La Nina means that the waters in the equatorial pacific are cooler than average. El Nino means the opposite.

La Nina is not the only driver, however, in winter weather. A big key is the NAO, which refers to pressure patterns in the Northern Atlantic. The higher the pressure there, the lower the pressure is in eastern North America and the colder our temperatures are. The pattern in the pacific also has a lot to do with our weather.

The NAO looks to be heading into a state in which plenty of cold air will be directed into the eastern U.S. later this month and into December. The above-average precipitation we've had over the last two months will continue, (into early spring in fact) so snow and even some ice will be around from approximately Thanksgiving through New Years.

The NAO may change a bit later January and February to allow for some moderation in temperatures (relative to average) but with above average precipitation continuing, we will still have to deal with plenty of snow, ice or rain.

Here's a month-by-month breakdown:

December - Above average precipitation, below average temperatures.

January - Above average precipitation, slightly below average temperatures.

February - Above average precipitation, slightly above average temperatures.

March - Above average precipitation, slightly above average temperatures.

What can go wrong? If the NAO returns to a strong and persistent negative state, which directs colder air into the eastern U.S., we will have colder than average temperatures and more snow than rain or ice in February and March.

Overall, expect a similar year to what we had last winter, but not exactly the SAME. Keep the snowblower and salt handy, along with the heavy coat. But most importantly, be careful! Dress properly for extreme cold when it comes and drive defensively when the snow and ice are on the roads. I want everyone to have a safe and happy holiday season!

I'll update the forecast later this winter to include any changes to the second half (if any), and recap what we've seen so far.