HISTORICAL CLIMATOLOGY OF NEW ENGLAND AND IMPLICATIONS FOR EVALUATING TRENDS IN EXTREME EVENTS

Over the past decade, the general public frequently has been told of the apparent increase in the number of extreme weather events that have occurred around the world, and more specifically in many places around the United States. The need to evaluate such changes is critical to establishing changing climatic conditions at the regional level, as regional climatic variability may differ from the overall global situation. Identifying changes in the number and magnitude of extreme events is particularly important because preparing for the impact of these events is potentially of greater importance to an individual’s socioeconomic well-being than would be preparation for overall changes in climate. Unfortunately, the very short instrumental record has been the primary basis for suggesting this increase in extreme events at the regional level. Written accounts, as in personal diaries, of past weather conditions across New England spanning the last 300-400 years provide extremely highly-resolved (daily) records to assess better how the number and magnitude of extreme events have varied across this region. For instance, many time periods in the18th and 19th centuries appear to have been “hit” with a greater number of nor’easters or just as many as we have seen in the past few decades. Many winter seasons, as in 1839 and 1893, have frequently had three to four major nor’easters within a week migrate along the eastern seaboard. Drifts of 15-25 ft high are frequently noted following several of these extended periods of high storm activity in the 1700 and 1800s. This suggests that the number of strong snow-producing nor’easters may not be increasing in recent times, but that the number of these large storms has continued to vary on perhaps decadal time scales over the last few centuries. It is interesting to postulate that individuals in New England were questioning the increase in extreme events in the region during 1888 when the area was impacted by the “hallmark” New England snowstorm and by three landfall hurricanes with a fourth just to the west of the region, a scenario that has not been repeated during the last century.