Blizzard of 2003

North American blizzard of 2003

Category 4 "Crippling" (RSI: 14.67)
Plowing the streets of Washington, D.C. during the Blizzard of 2003
Type	Winter storm
Formed	February 14, 2003
Dissipated	February 19, 2003
Lowest pressure	1011 mb
Maximum snowfall or ice accretion	112 cm/44 in Garrett County, Maryland
Damage	Over 14.1 million
Casualties	2 fatalities direct, 25 indirect
Areas affected	Southern Rockies, Central United States, Eastern North America

The Blizzard of 2003, also known as the Presidents' Day Storm II or simply PDII, was a historical and record-breaking snowstorm on the East Coast of the United States and Canada, which lasted from February 14 to February 19, 2003. It spread heavy snow across the major cities of the Northeastern and Mid-Atlantic states, making it the defining snowstorm of the very snowy winter of 2002-2003.

All cities from Washington DC to Boston were covered in 15–30 inches (380–760 mm) of snow and those cities were brought to a standstill due to problems caused by temperatures and the snow. In Baltimore and Boston, this was the biggest snowstorm on record, with 28.2 and 27.5 inches (71.6 and 69.9 cm) respectively.

The severity of the Blizzard of 2003 can be attributed to the unusually favorable atmospheric conditions surrounding the storm (synoptic conditions). Most notably, the storm allowed for cyclogenesis off of the coastal Carolinas, a feature that is common to most major winter storms in the eastern parts of North America. This secondary system fed off the moisture of the Atlantic Ocean and enhanced precipitation totals from North Carolina to Massachusetts. Secondly, a high pressure system was in place over eastern portions of Canada, allowing for cold air to be brought down into the coastal areas in a process known as cold air advection. This cold air ensured that many areas where storms typically produce mixed precipitation received most or all precipitation in the form of snow.

The storm developed in the southern Rockies on February 14, and moved through southern Missouri and the Lower Tennessee Valley during the next few days. It brought heavy rain, ice and severe weather to some areas of the South, including the nation's first tornado of the year. Farther north, snow and ice affected the Midwest. Southern Iowa and eastern Illinois also got significant snow, with 11 inches (28 cm) in Des Moines. In central Kentucky the storm produced mostly ice, with some locations including Frankfort, Lexington, and nearby Cynthiana in Harrison County receiving up to 3/4" (2 cm) of ice. Much of Ohio received heavy snowfall, with Mansfield receiving 21 inches and Columbus receiving about a foot.