The February 2013 North American blizzard, also known as Winter Storm Nemo and the Blizzard of 2013, was a powerful blizzard that developed from the combination of two areas of low pressure, primarily affecting the Northeastern United States and parts of Canada, causing heavy snowfall and hurricane-force winds. The storm crossed the Atlantic Ocean, affecting Ireland and the United Kingdom. The nor'easter's effects in the United States received a Category 3 rank on the Northeast Snowfall Impact Scale, classifying it as a "Major" Winter Storm.
The first low-pressure system, originating from the Northern Plains of the United States, produced moderate amounts of snow across the Great Lakes region of the U.S. and Canada. The second low, originating across the state of Texas, produced heavy rains and flooding across much of the Southeast and Mid-Atlantic parts of the U.S. As the two systems merged off the Northeast coast on February 8, 2013, they produced heavy snowfall over a large region from North Jersey and inland from New York City through eastern New England up to coastal Maine and inland to Ontario.
Total snowfall in Boston, Massachusetts, reached , the fifth-highest total ever recorded in the city. New York City officially recorded of snow at Central Park, and Portland, Maine, set a record of . Hamden, Connecticut recorded the highest snowfall of the storm at , the second highest total in Connecticut was recorded in Milford at . Many surrounding cities picked up at least . In addition to the significant snowfall totals, hurricane-force wind gusts were recorded, reaching in Nova Scotia, at Mount Desert Rock, Maine, and off the coast of Cuttyhunk, Massachusetts. Boston experienced a storm surge of , its fourth-highest. The storm affected Atlantic Canada after hitting the Northeastern United States.
Watches and warnings were issued in preparation for the storm, and state governors declared states of emergency in all states in New England and in New York. Flights at many major airports across the region were canceled, and travel bans were put into place on February 8 in several states. Hundreds ended up stranded on Long Island late on February 8 as a result of the rapidly accumulating snowfall. A combination of strong winds and heavy, wet snow left 700,000 customers without electricity at the height of the storm. At least eighteen deaths were attributed to the storm.
Meteorological history
Atmospheric conditions leading up to the formation of the February 2013 nor'easter were rather anomalous and were conducive for cyclogenesis. Such conditions included the presence of a ridge over the North Atlantic and the strengthening of a trough in California. The impactful nature of the eventual winter storm event was first predicted in National Centers for Environmental Prediction (NCEP) and Hydrometeorological Prediction Center (HPC) forecasts at 1200 UTC on February 6, when the accumulation of at least of snow in the ensuing hours was considered a moderate probability in parts of Wisconsin and Michigan. Fueled by energy originating from the Gulf of Alaska and carried by the polar jet stream, a low-pressure area formed as anticipated in Montana, at 1200 UTC the next day. The cyclone tracked in a general east-northeastward direction throughout the day, reaching central Indiana by early on February 8.
As the low-pressure system over the United States Midwest developed, energy associated with the subtropical jet over the Mexican plateau tracked into the Gulf of Mexico, resulting in the formation of another low-pressure area just off the coast of Texas on February 7. Tracking eastward, the system produced isolated severe weather across the United States Gulf Coast. Near noontime that day, the cyclone moved into the Florida Panhandle. By February 8, the low-pressure system had moved into Georgia. Both the system in the Gulf of Mexico and the system in the Midwestern United States were supported by the same shortwave trough. Due to blocking steering patterns, both storms began to gravitate towards the Eastern Seaboard.