Monday, December 26, 2011

Tracking Richmond's First Chance of Snow

It looks fairly certain we'll finish up December 2011 without a trace of snow, something we haven't seen since 2006. The pattern looks like it could finally make a big shift in early January, bringing much colder air, and possibly the first snowflakes of the season to the area. The various models solutions continue to hint at both colder and snowier weather for the area during the period of January 2nd-7th. Model reliability is typically poor that far ahead, and there have been many departures from the cold solution over the past couple of days. What has drawn my eye has been the persistent signal of a deep and very cold trough digging into the eastern U.S. in response to a negative shift in the North Atlantic Oscillation (NAO). The European Model has been pretty consistent over the past few runs will the colder air, while the GFS has flip-flopped a couple of times and can't seem to settle on a particular pattern for early January. Most recently, and perhaps the most alarming, is the loose agreement of a full-blown Nor'easter on January 5th. We'll certainly see some changes in the solutions over the next few days, and what is there today, could very easily be gone tomorrow. From the signals I've seen over the past several days though, winter could finally make an appearance during the first week of 2012. Check back for another update. -Zach