We heard from a lot of folks over the past few weeks who remembered last year's snow that began late Christmas Day and ended up a significant event for most of our area, generally hoping we might have a repeat in 2011. That didn't happen of course, and not only that, we've lived in almost a different world weatherwise for the December just finished compared to the one we experienced one year earlier.
In 2010, December featured frequent development of a deep upper level trough across the eastern U.S. that left us with frequent blasts of very cold air, and subject to the occasional snow-producing storm system. In 2011, however, the upper-level "see-saw" was tilted the other direction, with a persistent trough over the western U.S. resulting in a general west to southwest flow in the east that brought above-normal temperatures our way.
More specifically, here's how the numbers stack up for the Raleigh-Durham airport for the two Decembers. In 2010, the mean monthly temperature there ended up at 34.9 degrees, which was 8.1 degrees below normal. To go along with that, we had 2.39 inches of precipitation, which included 8.3 inches of snow. The December just ended was a very different story, closing out with an average monthly temperature of 48.5 degrees, a full 5.0 degrees above normal. We total 2.05 inches of precipitation, all of which reached the surface in liquid form.
We are in the midst of a blast of much colder air right now, but it appears it will come nowhere near record levels and will also abate rapidly by later in the week. The current projection from the Climate Prediction Center (the image included here) for a good part of the next week or two also favors a strong chance of above-normal temperatures during that period.