For several years in some parts of the nation, increasing numbers of seasonal forecasts have been issued from an increasing number of outlets. Unfortunately - depending upon the issuing outlet - typically seasonal verification isn't too much above 50% - just a bit better than flipping a coin. Monthly forecasts, however, hold more promise for accuracy (though still can meet with peril), so Friday night, rather than dabble in seasonal forecasting, I shared my expectation for the month of December for both temperature and precipitation, both nationally and at home in New England. For a complete explanation, I invite you to view the video forecast below. Scroll past the video forecast to see some of the nitty gritty of what I'm expecting.
As we stand on the cusp of December, and since I regularly make 8-14 day forecasts each week for air, the first half of the month is shaping up rather clearly, and it looks warmer than normal. The first week of December should be squarely above normal, with just one brief period of cooling, and the second week of the month likely will come in very close to normal or perhaps just slightly above. In a pattern of regularly oscilating temperatures in the Northeast, this will likely be followed by a period of warmth - and perhaps rather significant warmth - for at least part of the third week of the month. By Christmas, however, I have moderate confidence on a pattern shift that will allow intense cold to drop into the Northeast for a longer period of time, at times perhaps some 10-20 degrees below normal sometime between December 24 and the end of the year. This substantial cold is the reason I'm forecasting near normal temperatures for the month, as the total number of cold days may be smaller, but the intensity may be higher.
-Matt
