This Month in Climate History: February 4–7, 2010, Blizzard

Image of February 4-7, 2010 snow in Charles County, Maryland

A view of rural Charles County, Maryland, and the snow left by the major winter storm that forced government offices in Washington, DC, to close for most of a week. (Photo by Jackie St Clair of Compton, Maryland)

A major winter storm crippled the U.S. Mid-Atlantic region the first week of February 2010. This snowfall, with record or near-record totals at each of the three major Washington D.C. airports, began during the evening of February 4 and continued through February 7 before finally ending that morning. Winter storm watches were posted for the Washington and Baltimore metropolitan areas at 2:45 PM on February 3. These watches were subsequently upgraded to winter storm warnings at 9:59 AM on February 4 as the impending blizzard drew nearer.

The setup for winter storms in the Mid-Atlantic usually contains three elements. First is high pressure to the north, which keeps the cold air in place during the storm. The second element is a ridge of high pressure over the western portion of the Nation. This allows low pressure to strengthen over the Deep South while the system draws in moisture from the Gulf of Mexico. Third is an area of deepening low pressure that tracks slowly northward along the Mid-Atlantic Coast.

All three of these elements were present during the major winter storm on February 4–7, 2010. High pressure over upstate New York into New England pumped in plenty of cold air from the north ahead of the storm. Surface low pressure over the Deep South strengthened as it combined with an upper-level low over the central portion of the Nation. As the low tracked through the Tennessee Valley, it transferred its energy to another area of low pressure developing off the Southeast Coast. This low rapidly intensified as it slowly tracked northward along the Mid-Atlantic Coast on February 6. The system drew in deep moisture from the Gulf of Mexico and Atlantic Ocean, resulting in heavy amounts of precipitation. Due to the slow movement of the storm, there was a prolonged period of heavy snow the night of the fifth into the morning of the sixth. By the time the storm finally ended on February 7, locations from western North Carolina up through middle Pennsylvania reported between 10 and 30 inches of snow.

Washington Dulles International Airport reported a record two-day snowfall total of 32.4 inches. This shattered the previous two-day record of 23.2 inches set in 1996. The two-day snowfall total at Baltimore–Washington International Airport was 25.0 inches, second only to January 27–28, 1922, when 26.3 inches of snow fell. Snowfall totaled 17.8 inches at Ronald Reagan Washington National Airport, which as the fourth greatest two-day snowfall total for Washington, DC, at the time.

The storm brought transportation nearly to a halt across the region. Power outages were reported across the Baltimore and Washington metropolitan areas due to the heavy snow that accumulated on trees and power lines. Schools, and many businesses and governments, remained closed for several days following the storm. Overall, the storm ranked three out of five on the Regional Snowfall Index and affected over 45 million people in the Northeast alone.

Another major snowstorm followed closely on the heels of this one between February 9 and February 11, 2010. On top of the feet of snow already on the ground in many places, this storm dumped several more inches on the U.S. Northeast. By the time the second storm cleared the East Coast, thousands of flights had been cancelled, Amtrak suspended service in the hardest hit areas, and local rail and bus service was disrupted. Local transportation was so impaired that the federal government in the Washington, DC, area shut down for four and a half days, and schools and businesses remained closed for most of the week.

While the second storm only ranked two out of five on the Regional Snowfall Index, when combined and treated as one storm, the resulting total of the two storms would become one of only three category five storms—the most extreme–in the Northeast.

For more information on U.S. weather and climate conditions during the month, see the February 2010 U.S. Climate Report.