As millions of Americans are taking to the highways for the Thanksgiving holiday, a powerful winter storm is plowing across the nation. The storm is leaving snow, ice, and rain in its wake, creating hazardous travel conditions. By the time the storm is over, it will have brought wintery weather to 2.5 million square miles of the United States.
The storm is big news because it is disrupting travel during one of the busiest travel period of the year, but it’s not otherwise all that unusual, says NASA research scientist Chris Kidd. “Large storms are expected a few times each winter, particularly at this time of the year,” says Kidd. Ocean waters in the Gulf of Mexico are still warm—around 80 degrees Fahrenheit—and they load the atmosphere with moisture. Meanwhile cold Arctic air is beginning to sweep down from the north. When that cold air clashes with warm, moist air from the south, it is the perfect recipe for a large storm system.
These images and animations show the storm system between November 24 and 26, 2013. The top image and associated animation show water vapor from the GOES East satellite, while the lower image and animation show clouds. The clouds offer a familiar view of the storm, but water vapor reveals the otherwise invisible clash between warm and cold air that is generating the storm.
The winter storm that is snarling Thanksgiving travel in the central and eastern United States left a path of snow across the desert Southwest earlier in the week. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this image on November 26, 2013, after the clouds cleared. The National Weather Service reports snowfall totals ranging from 41 inches in Utah to 2 inches in parts of Oklahoma and Kansas. All of the states shown received significant snowfall from the storm.