New England Snow Cover, 15 January 2004
An Arctic cold front swept through the New England states, plunging temperatures to below zero for several days in mid-January. Schools in several communities cancelled classes, police advised motorists to stash extra clothing in their vehicles, and the National Weather Service sent an advisory warning to watch for frostbite. New York City and Philadelphia each received close to five inches of snow on January 15.
The frigid conditions across New England are depicted in the following image, derived from the MODIS/Aqua Snow Cover 5-Min L2 Swath 500m, Version 4 data set, available from NSIDC. The MODIS snow mapping algorithm is based on the Normalized Difference Snow Index (NDSI), which distinguishes between clouds and snow and ice. The NDSI measures the difference between visible and shortwave infrared reflectances of snow. MODIS snow products at 500 m resolution are useful for hydrologists studying the annual snowpack and water supply in this region.
The following file is the source file used to create this image: