This week may bring the largest snowstorm of the winter to Addison County, but it will pale in comparison to the storms of last year - and to the forecasts many made last fall of a snowy winter. As winter nears its end, it is a good time to look back at these winter forecasts and see how they fared against actual conditions.
The verdict? Just about all of the long-range forecasts I mentioned last fall, as well as my own guesses, were well off the mark! Most of the weather outlooks from last fall featured a winter with near-average temperatures and heavy snowfall. Instead we’ve experienced a very mild winter with changeable but warmer than average temperatures, and very little snow. The lack of snow was not only due to warm weather but also due to much drier conditions than we experienced last spring and summer.
(photo: instead of a snowy winter, we have experienced a mild and nearly snowless winter thus far. Sugaring season has started early, and there is little or no snow on the ground in the Champlain Valley.)
The majority of the United States has experienced a mild winter, with the exception of Alaska, which has been even snowier and colder than usual. Europe also experienced a very severe cold snap earlier this month.
The likely cause for Vermont’s mind conditions? The positive Arctic Oscillation jet stream pattern that I posted about in January has continued for much of the winter. In contrast, last year’s winter featured a negative Arctic Oscillation pattern. The negative pattern often correlates with heavy snow in Vermont, while the positive pattern is associated with mild winters. There are some signs that early spring may be wetter than the winter has been, but as temperatures rise we may be left with rain rather than snow.
Were there any signs of a mild winter to come that were evident last fall? I did notice that the woolly bear caterpillars ‘seemed redder than usual’, which some believe foretells a mild winter. There isn’t much scientific credibility to this story, but I’ll be looking out for these caterpillars next fall anyway. Meanwhile, perhaps some Vermonters who have been through many more winters than I may have had the feeling that a mild winter was on the way. During my time in California I noticed that changes in acorn production seemed to be linked to the next winter’s rainfall, but I havent yet noticed anything similar in Vermont. Does anyone watch animals or plants as a possible indicator of future weather? Or, do you just prepare for the worst and hope for the best?
Charlie Hohn is a recent graduate of the UVM Field Naturalist graduate program. He has been closely watching the weather ever since he was a child in southern California. Charlie will be posting occasional blog posts here about Addison County weather. He also maintains a blog about water at slowwatermovement.blogspot.com.