Modeled Precipitation Difference Between 2010 Snowmageddon Event and Winter of 2000

Three major snowstorms hit the east coast of the United States in the winter of 2009-2010. Scientists then posed the following question: What was the role of climate variability during this extreme winter? Utilizing high end computing resources at the NASA/Goddard Space Flight Center, scientists employed the use of the GEOS-5 atmospheric model in an ensemble of simulations to answer this question. Two case studies were produced. One was the winter of 2009-2010 and the other was the same months during the winter of 1999-2000. 50 member ensembles of high resolution simulations were run (each 3-months long beginning on December 1st for each winter).

The resulting findings were that GEOS-5 simulations forced with observed Sea Surface Temperatures (SST) reproduce observed changes, including enhanced storminess along the United States east coast. The ensemble members showed that this is a robust response, and verified that anomalous weather events over the U.S. are, to a large extent, driven by El Niño SST. Furthermore, North Atlantic SST contributes to the coolor (snow-producing) temperatures along the U.S. east coast.

By subtracting the results of the 1999-2000 runs from the 2009-2010 a difference map can be generated showing the areas that received more precipitation and areas that received less precipitation. Areas that received more precipitation in 2009-2010 over 1999-2000 are depicted in shades of green. Areas that received less precipitation between these two winters are depicted in shades of brown.