Western Atlantic sea surface temperatures and Northeastern United States precipitation, 1896–1995

Sea surface temperatures in the far western North Atlantic Ocean are examined in parallel with divisional precipitation totals for the U.S. Northeast corridor from southern New Hampshire to Maryland. Monthly data include serially and spatially complete SST data at 2° lat./2° long. from 1950-92, less spatially complete SST data at 5° lat./5° long. from 1896-1995, and precipitation data from U.S. climate divisions from 1896-1995. Divisional data are areally weighted to generate regional averages. All data are evaluated in seasonal increments.

Seasonal relationships between regional precipitation and SST anomalies from subregions of the western Atlantic are explored contemporaneously and with precipitation lagged by one season. Significant positive relationships are noted for spring precipitation and SSTs immediately offshore of the continental study region and for summer precipitation and SSTs east of Newfoundland. A negative relationship is found between spring SSTs off Newfoundland and Labrador and summer precipitation. The most significant association is a positive one between winter SSTs immediate offshore of the Corridor and spring precipitation. All relationships are significant for the late and full century periods.

These associations are evaluated with respect to 700 mb height anomalies and NAO and ENSO indices. For instance, the winter SST/spring precipitation relationship is associated with a lack of troughing and a positive NAO in cases where the SSTs are above average.