Does a wintry November hint at cold, snowy winter ahead?
Winter has settled in a month early in the eastern two-thirds of the country still shivering after a historic arctic blast that has shattered more than 400 mid-November records (record-cold daily highs and lows) since Veterans Day.
The logical question now is whether the cold and expanding snow cover over the northern United States is a harbinger of a tough winter ahead.?
The National Weather Service outlook issued by NOAA’s Climate Prediction Center in late October is not predicting below-normal temperatures in the three-month average (December-February) across the nation.
Winter precipitation is expected to above normal across the northern Plains, Upper Midwest and Ohio Valley, which could fall more often as rain or mixed rain and snow if the temperature prediction is correct.
Of course, snowstorms and cold waves occur in the midst of a mild winter, and last year we were visited by the polar vortex in an otherwise warmer-than-normal season.
There are no clear answers, but some historical hints suggest the scales may be tipped a little in the direction of a colder and snowier winter.
I analyzed average November temperatures for Ohio, early snowfalls in Columbus and the winter outcome. There are 124 years of official data, so I divided the records into three categories: colder-than-normal (40 coolest December-February temperatures); average (rank 41-80), and warm (81-124).
The results suggest a colder-than-normal November, which requires multiple rounds of arctic air and undoubtedly fairly widespread snow cover to keep the air chilled, slightly favors cold winters compared to warm and near-normal seasons.
More strikingly, in Columbus, when we have experienced an early significant snowfall around or heavier than 2 inches, that correlates with twice the odds of having a cold versus a warm winter, and more likely than a warm or near-normal winter season.
Overall, winters with an early snowfall tend to end up snowier than average, although that may also reflect an earlier contribution to the total snowfall.