Atmosphere And Weather

How Noreasters Form

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"How Noreasters Form"
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If you live in the Northeastern United States, there is no doubt that you have heard the term “Nor’easter” many times in your life.

Nor’easters are storms that occur along the East Coast most often during the fall, spring, and winter months. They get their name from the northeast winds which blow as they hit.

However, in order to understand why they develop and why they have become such a big part of American culture, it is important to look at the way in which they develop.

The classic nor’easter begins its life along the southern United States coast near the Gulf of Mexico. There, it gathers tropical moisture and rides the southern jet stream to the west.

But, as this fledgling low pressure system reaches the eastern coast over the next couple of days, it will begin to make a turn to the north as the jet stream enters a steep ridge. From there, the nor’easter will rapidly gather strength as it undergoes what is known as bombogenesis, which is characterized by a rapid drop in central pressure. As it speeds up the east coast, the storm can take a few different tracks.

The first occurs when high pressure is located near the Great Lakes. If this high is strong enough, it can block the storm and cause it to turn well out to sea, sparing coastal cities from any impact whatsoever.

The next scenario is equally as common, and it happens when there is a Bermuda high in place, which will prevent the storm from going out to sea, causing it to go directly up the coast. It could even track somewhat inland. Nevertheless, if a storm takes this track, it will impact the major east coast cities with heavy rain or snow.

However, the final scenario, which is the least common of the three, creates the most powerful and memorable nor’easters. This scenario results from a strong blocking high pressure area placed over southeastern Canada which causes the storm to stall out just off the coast.

If a Nor’easter stalls, it can bring heavy snow or rain to the Northeast over the course of a few days until it finally moves along or dissipates.

Some of the most infamous nor’easters have taken this track, such as the Northeastern United States Blizzard of 1978, which stalled near Martha’s Vineyard for 2-3 days, dumping up to and over 2-3 feet of snow on parts of Southern New England.

Other notable Nor’easters have included the Blizzard of 1888, 1993’s “Storm of the Century,” and the Blizzards of 1996 and 2005.

All of these storms brought large quantities of snow to northern cities, which ground travel to a halt, as well as claimed the lives of many.

The fact that this scene has played out so many times in the past goes to show the power of these storms. There is no doubt that there will be more extremely powerful nor’easters in the future, so cities along the East coast must always remain prepared for the worst.

More about this author: Bradford Guay

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