February 5–6, 2010 North American blizzard

The February 5–6, 2010, North American blizzard, commonly referred to as Snowmageddon, was a blizzard that had major and widespread impact in the Northeastern United States. The storm's center tracked from Baja California Sur on February 2, 2010, to the east coast on February 6, 2010, before heading east out into the Atlantic. Effects were felt to the north and west of this track in northern Mexico, California, and the southwestern, midwestern, southeastern, and most notably Mid-Atlantic states. Severe weather, including extensive flooding and landslides in Mexico, and historic snowfall totals in every one of the Mid-Atlantic states, brought deaths to Mexico, New Mexico, Virginia, Pennsylvania, and Maryland.

Most crippling was the widespread 20 to 35 in (50 to 90 cm) of snow accumulated across southern Pennsylvania, the Eastern Panhandle of West Virginia, northern Virginia, Washington, D.C., Maryland, Delaware, and South Jersey, bringing air and interstate highway travel to a halt. Rail service south and west of Washington, D.C., was suspended, and rail travel between D.C. and Boston was available with limited service. Blizzard conditions were reported in a relatively small area of Maryland, but near-blizzard conditions occurred across much of the Mid-Atlantic region.

This event was the second of four nor'easters during the 2009–2010 winter that brought heavy snow to enough of the Northeast's population to be numerically recognized by NOAA's NESIS intensity rating. The first and third of these systems, the December 2009 Northeastern U.S. blizzard and the February 9–10, 2010 North American blizzard, respectively, combined with this event to bring the snowiest winter on record to much of the Mid-Atlantic. Additionally, this event was the second of three major Mid-Atlantic snowstorms that occurred over a 12-day period; each subsequent storm focused its heaviest snow slightly farther north: the January 30, 2010, storm (not recognized by NESIS) dropped more than a foot of snow across Virginia and the lower Chesapeake Bay region, while the February 9–10, 2010 North American blizzard bulls-eyed the Maryland-Pennsylvania border with as much as 38.3 inches.