Nor'easter

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Image:GreatBlizzardof2006.jpg

Satellite image of the intense nor'easter responsible for the North American blizzard of 2006. Note the hurricane-like eye at the center.

A nor'easter (also northeaster; see below) is a macro-scale storm along the East Coast of the United States. A nor'easter is so named because the winds in a nor'easter come from the northeast, especially in the coastal areas of the Northeastern United States and Atlantic Canada. More specifically, it describes a low pressure area whose center of rotation is just off the East Coast and whose leading winds in the left forward quadrant rotate onto land from the northeast. The precipitation pattern is similar to other extratropical storms. Nor'easters also can cause coastal flooding, coastal erosion, hurricane force winds, and heavy snow. Nor'easters can occur at any time of the year but are mostly known for their presence in the winter season.^[1] Nor'easters can be devastating and damaging, especially in the winter months, when most damage and deaths are cold related, as nor'easters are known for bringing extremely cold air down from the Arctic air mass. Nor'easters thrive on the converging air masses; that is, the polar cold air mass and the warmer ocean water of the Gulf Stream.^[2] Nor'easters will usually develop between 30 N. and 35 N.

1 Formation
2 Characteristics
3 "Nor'easter" usage and origins
4 Notable Nor'easters
5 See also
6 References
7 External links

[edit] Formation

Image:11z March 13 Surface Analysis Blizzard 1996.jpg

Surface Analysis of a forming Nor'easter over the South Carolina Coast that would later become The Blizzard of 1996

Nor'easters usually form off of the Carolina coast, in the winter months when Labrador currents and the warm Gulf Stream current meet. The sharp contrast in air temperatures above these currents allows a low pressure system to form. Meanwhile, over Canada, winds move in a clockwise direction around a High pressure system. These winds move far into the northeastern United States, bringing in Arctic air that allows freezing precipitation. The low pressure system begins to move up the coast. At the same time, air rushes counterclockwise around it, bringing winds that blow from the northeast, hence the name, "nor'easter." These winds pick up moisture from the ocean. Lift causes the moisture to rise and form clouds and precipitation. If the clouds are trapped east of the Appalachian Mountains, they drop precipitation on areas along the coast.^[3]

[edit] Characteristics

Nor'easters are usually formed by an area of vorticity associated with an upper-level disturbance or from a kink in a frontal surface that causes a surface low pressure area to develop. Such storms very often are formed from the merging of several weaker storms, a "parent storm" and a polar jet stream mixing with the tropical jet stream.

Until the nor'easter passes, thick, dark, low-level clouds often block out the sun. During a single storm, the precipitation can range from a torrential downpour to a fine mist. Low temperatures and high wind gusts are also associated with a nor'easter. On very rare occasions, such as in the North American blizzard of 2006 and a nor'easter in 1979, the center of the storm can take on the circular shape more typical of a hurricane and have a small eye. All precipitation types can occur in a nor'easter, although they are well-known for their frozen precipitaion.

[edit] Difference from Tropical Cyclones

Often, people mistake nor'easters for tropical cyclones and do not differentiate between the two weather systems. Nor'easters differ from tropical cyclones in that nor'easters are cold-core low-pressure systems, meaning that they thrive off of cold air. Tropical cyclones are warm-core low-pressure systems, which means they thrive off of warm temperatures.

[edit] Difference from other extratropical storms

Though a Nor'easter is formed in a strong extratropical cyclone, which occur in many places around the world, they are unique in the combination of northeast winds and moisture content of the swirling clouds. Close to similar conditions sometimes occur during winter in the Pacific Northeast (northern Japan and northwards) with winds from NW-N. In Europe, similar weather systems with such severity are hardly possible; the moisture content of the clouds is usually not high enough (to cause flooding or heavy snow), though NE winds can be strong.

[edit] Areas often affected

The northeastern United States, from New Jersey to the New England coast, Quebec and Atlantic Canada see nor'easters each year, most often in the winter and early spring but also sometimes during the autumn. These storms can leave inches of rain or several feet of snow on the region and sometimes last for several days.

The Atlantic coast, from northern Georgia northward up the coast, can suffer high winds, pounding surf, and extremely heavy rains during these storms. However, swells have been known to cause damage through the Caribbean as well. Surfers wait in anticipation when a nor'easter is formed. Nor'easters cause a significant amount of severe beach erosion in these areas, as well as flooding in the associated low-lying areas. Beach residents in these areas may actually fear the repeated depredations of nor'easters over those of hurricanes, because nor'easters happen more frequently and cause substantial damage to beach-front property and their dunes. Nor'easters are often mistaken for Euroclydons, but these are two separate weather patterns. A Euroclydon is a tempestuous northeast wind that blows in the Mediterranean.

[edit] "Nor'easter" usage and origins

The term "nor'easter" comes to American English by way of British English and the points of the compass and wind or sailing direction. According to the Oxford English Dictionary (OED), the first recorded use in the English language of the term "nore" ("north") in association with the points of the compass and wind direction is by Dekker in 1612 ("How blowes the winde Syr?" "Wynde! is Nore-Nore-West."), with similar uses occurring in 1688 (". . . Nore and Nore-West . . .") and in 1718 (". . . Nore-west or Nore-nore-west."). These recorded uses are predated by use of the term "noreast," first recorded as used by Davis in 1594 ("Noreast by North raiseth a degree in sayling 24 leagues.") and shown, for instance, on a compass card published in 1607. Thus, the manner of pronouncing from memory the 32 points of the compass, known in maritime training as "boxing the compass", is described by Ansted (A Dictionary of Sea Terms, Brown Son & Ferguson, Glasgow, 1933) with pronunciations "Nor'east (or west)," "Nor' Nor'-east (or west)," "Nor'east b' east (or west)," and so forth. According to the OED, the first recorded use of the term "nor'easter" occurs in 1836 in a translation of Aristophanes. The term "nor'easter" naturally developed from the historical spellings and pronunciations of the compass points and the direction of wind or sailing.

As noted in a January 2006 editorial by William Sisson, editor of Soundings magazine, use of "nor'easter" to describe the storm system is common along the U.S. East Coast. Yet it has been asserted by some that "nor'easter" as a contraction for "northeaster" has no basis in regional New England dialect and is a "fake" word, which is a parochial view that neglects the little-known etymology and the historical maritime usage described above.

According to a handful of 20th-century Maine-based authors, 19th-century Downeast mariners pronounced the compass point "north northeast" as "no'nuth-east," and so on. For decades, Edgar Comee, of Brunswick, Maine, waged a determined battle against use of the term "nor’easter" by the press, which usage he considered “a pretentious and altogether lamentable affectation” and "the odious, even loathsome, practice of landlubbers who would be seen as salty as the sea itself." His efforts, which included mailing hundreds of postcards, were profiled, just before his death at the age of 88, in The New Yorker.^[4]

Despite the efforts of Mr. Comee and others, use of the term continues by the press. According to Boston Globe writer Jan Freeman, "from 1975 to 1980, journalists used the nor'easter spelling only once in five mentions of such storms; in the past year (2003), more than 80 percent of northeasters were spelled nor'easter."^[5]

University of Pennsylvania linguistics professor Mark Liberman has pointed out that while the OED cites examples dating back to 1837, they represent the contributions of a handful of non-New England poets and writers. Liberman posits that "nor’easter" may have originally been a literary affectation, akin to "e'en" for "even" and "th'only" for "the only," which is an indication in spelling that two syllables count for only one position in metered verse, with no implications for actual pronunciation.^[6]