What is a nor'easter?

The Northeast United States is sometimes plagued with storms called nor'easters. These storms can happen at any time of the year. However, they are most common between September and April. The East Coast is the perfect region for these storms to develop.

Typically, an area of low pressure will develop within 100 miles of the Southeast Coast. The warm water in the Gulf of Mexico and around Florida will warm the air above the low. As the low moves its way up the eastern seaboard it feeds off the Gulf Stream waters.

That warm air will clash with the cold air coming down from Canada. As a result, the storm intensifies and the winds pick up to 50 mph or greater around the storm. Those northeast winds that move around the low actually define a nor'easter, also known as a northeaster.

Tropical-storm-force winds create large waves and high water levels. Beach erosion, rough ocean waves, and flooding are often a damaging result, according to meteorologist Steven DiMartino, the owner of NY NJ PA Weather.

"If you can get a nor'easter to stall out off the coast, you can have extreme coastal flooding," DiMartino said. "And some damage that could last years before they can get any recovery."

Nor'easters usually produce a mix of snow, sleet, and rain. Each weather element is dependent on the storm track.

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"The track of the storm is very important. What we look for is what we call the 'benchmark, which is about 40 North 70 West. If a low-pressure system tracks through that benchmark, it's far enough off the coast to keep cold air in place and also draw moisture into the region, allowing for snowfall," DiMartino said. "If the track is closer to the coast, that allows warm air to invade the coast that leads to a changeover to rain."

Snow and winds over 50 mph can create blizzard conditions that can last for hours. Because of a nor'easter's usual track through the northeastern states, major cities like Washington, D.C., New York, and Boston are in its path. Therefore, millions of people are usually affected.

"Basically, it's the worst place possible to have a major storm like this because even though it may not directly impact you, it impacts everyone because of shipping delays and also travel concerns," DiMartino said.

Whether it brings snow, heavy rain, or strong winds, a nor'easter can be a disruptive type of storm.