Variability of Winter Storminess in the Eastern United States during the Twentieth Century from Tide Gauges

Interannual to multidecadal variability of winter storminess in the eastern United States was studied using water level measurements from coastal tide gauges. The proximity to the coast of the primary winter storm track in the region allows the use of tide gauges to study temporal modulations in the frequency of these storms. Storms were identified in high-passed, detided sea level anomalies in 20 gauges from all coasts of North America to assess variability in winter storminess along particular storm tracks. The primary result is a significant multidecadal increase in the number of storms affecting the southeastern United States from the early to late twentieth century. The authors propose that this change is due to an increased tendency for the jet stream to meander south over the eastern United States since the 1950s. This mechanism is supported by long-term changes in the large-scale sea level pressure pattern over North America. The nature of the multidecadal change in storm frequency is unclear, because limited tide gauge record lengths prevent distinguishing between a trend and an oscillation.