What Exactly is a Nor’easter?
A Nor’easter occurs when a powerful polar jet stream dips southward and converges with a developing low-pressure system originating in the Gulf of Mexico or southwest Atlantic. Typically, this system originates from a frontal boundary extending across the Gulf Coast and Florida. As the low-pressure system tracks up the Eastern Seaboard, it often undergoes rapid intensification, leading to significant snowfall in the mid-Atlantic and parts of the interior Northeast. Due to its trajectory, areas along the I-95 corridor usually experience more rainfall than heavy snow, reducing snow accumulation rates. This illustration clarifies the concept of Miller Type A nor’easters. Miller Type A events are more prevalent during La Niña patterns compared to El Niños, as the northern jet stream tends to be more active than the southern subtropical jet. Some of the most powerful non-hurricane storm systems have been attributed to Miller Type A storms. For instance, the Superstorm of 1993, a Miller Type A event, stands as the most destructive nor’easter in U.S. history. Dubbed the “Storm of the Century,” this system brought hurricane-force wind gusts, tornadoes, flooding, and blizzard conditions that resulted in over 300 fatalities and initial damage estimates exceeding $5 billion.
Unraveling the Scent of Rain
December 22-24, 1989: The Christmas Coastal Snowstorm
A storm system originating in the Gulf of Mexico and tracking along the southeastern coastline created an unprecedented snowfall event for communities in the Deep South. With sufficient cold air in place, instead of rain or severe weather, cities spanning from Florida to the coastal Carolinas witnessed record snowfall. Historical NOAA data indicates that Wilmington, North Carolina, received 15″ of snow, while Charleston and Jacksonville recorded 3.9″ and around 2″ of snow respectively. The NWS reported widespread power outages and severe crop damage due to the frigid temperatures gripping the region for several days. Winds reached up to 60 mph, and wave heights ranged from 25-35 feet in near-shore waters from Virginia to the Carolinas, with Virginia and the Delmarva Peninsula experiencing the northernmost impact. The system veered out to sea, avoiding a direct hit on the Northeast.
March 12-14, 1993: The Storm of the Century
A low-pressure system emerged on March 12th along a nearly stationary front along the Gulf Coast, giving rise to the formidable “Storm of the Century.” This system unleashed hurricane-force wind gusts, tornadoes, flooding, and blizzard conditions across a significant portion of the eastern U.S. During its journey from the Gulf Coast up the Eastern Seaboard, the system’s barometric pressure plummeted to as low as 960 mb, akin to a Category 3 hurricane. More than 10 million residents
The storm system, according to NOAA, resulted in the tragic loss of over 300 lives, while the initial assessment of damages exceeded $5 billion in the aftermath of the event that occurred from December 18th to 20th, 2009, known as the North American Blizzard of 2009. This powerful nor’easter took shape over the weekend before Christmas in the Gulf Coast region, causing widespread impacts along the Appalachians, as well as in the southern regions of the Northeast and New England. The storm’s trajectory resulted in substantial snow accumulation from the Appalachians all the way to Long Island, where certain areas reported snow depths exceeding 2 feet. Strong wind gusts ranging from 40 to 50 mph prompted the issuance of Blizzard Warnings from the nation’s capital down to Long Island. The Southeastern states, including Georgia and the Carolinas, faced severe icing conditions that disrupted travel. Despite its significant impacts, the storm system was rated a 2 out of 5 on NOAA’s impact scale, considering factors such as precipitation levels and the number of people affected. Following closely on the heels of this event was the 2009 North American Christmas blizzard, which brought even more extensive effects across a larger geographical area, earning a maximum rating of 5 on the impact scale.
