New England Winter Climate and Related Teleconnections

For a general summary go to: "El Nino, the North Atlantic Oscillation and New England Climate" at the University of New Hampshire's AIRMAP website.

For related papers and data see my publications page.

New England Winter Forecasting

This work represents a continuation of an ongoing collaborative effort between myself, Barry Keim and Cameron Wake at UNH's Climate Change Research Center.

SUMMARY:
To provide a basis for future winter hydroclimatic forecasting, New England (NE) regional precipitation, snowfall, temperature and streamflow records have been compared with indices for the North Atlantic Oscillation (NAO), El Nino/ Southern Oscillation (ENSO), and NE regional sea surface temperatures (SSTs). Results have revealed a complex array of interrelationships between these variables on several spatial and temporal scales. Evidence for physical mechanisms responsible for the observed statistical links (e.g., regional storm tracking and tropospheric airflow patterns) have also been investigated and established. This processed-based understanding of the causes for past changes in low-frequency (monthly to interannual) variability in NE hydroclimate will be applied to empirical climate prediction models of winter snowfall and streamflow across the region.

While the phase of ENSO is known to relate with East Coast winter cyclone activity and its predictive value is well documented in several tropical and extratropical regions, ENSO’s signature in NE winter climate is only marginally apparent, making it (alone) of little use as a basis for seasonal forecasting. On the other hand, given recent reassessments of the predictive value of the NAO (and the related Northern Hemisphere Annular Mode), via lagged associations between stratospheric and surface weather patterns, observed teleconnections between the NAO and NE winter climate may offer our best hope for improving regional forecasts. Additionally, NE regional SSTs, which are well correlated with nearly every aspect of NE winter climate, may eventually prove to have some predictive value, due to their observed persistence and the tendency for their anomalies to lag the phase of the winter NAO by up to two years.