Usually what happens is you have a very strong storm that forms along the Gulf Coast, and as the jet stream brings it northeast along the Atlantic Coastline, it meets up with a large arctic air mass moving south from Canada. The combination creates a huge storm -- sometimes 600 miles across.
They are known to produce heavy rain and snow, hurricane-force winds, and can produce huge waves offshore that relentlessly pound the coastline, causing severe beach erosion and damage to shoreline property.
It gets its name from the strong northeast winds that blow from the storm.
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