The Northeast Snowfall Impact Scale (NESIS) was created to measure snowstorms in the

U.S. The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

Northeast in much the same way the Saffir-Simpson Hurricane Scale records

hurricane A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...

intensity and the Enhanced Fujita Scale with

tornado A tornado is a violently rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. It is often referred to as a twister, whirlwind or cyclone, altho ...

es.

The Scale

NESIS was created by

Paul Kocin Paul Kocin (born May 6, 1955) is a meteorologist and winter weather expert. He grew up on Long Island, New York and received his B.S. from Cornell University, followed by his M.Sc. from Pennsylvania State University. After graduation, he briefly ...

of The Weather Channel and Louis Uccellini of the

National Weather Service The National Weather Service (NWS) is an Government agency, agency of the Federal government of the United States, United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weathe ...

, classifies storms in one of five ways that range from ''Notable'' (the weakest designation) to ''Significant'', ''Major'', ''Crippling'', and ''Extreme''. storms have on the economy and transportation throughout the major cities in the Northeastern United States as well as the country as a whole.http://www.ncdc.noaa.gov/snow-and-ice/nesis.phpref The variables measured on the scale include area, amount of

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

fall, and the number of people living in the path of the storm. These numbers are calculated into a raw data number ranging from "1" for an insignificant fall to over "10" for a massive snowstorm. Based on these raw numbers, the storm is placed into one of the five categories. The largest NESIS values result from storms producing heavy snowfall over large areas that include major metropolitan areas. Only three historical storms—the

1993 Storm of the Century The 1993 Storm of the Century (also known as the 93 Superstorm, The No Name Storm, or the Great Blizzard of '93/1993) was a cyclonic storm that formed over the Gulf of Mexico on March 12, 1993. The cold weather, heavy snowfall, high winds and st ...

, the

North American blizzard of 1996 The North American blizzard of 1996 was a severe nor'easter that paralyzed the United States East Coast with up to of wind-driven snow from January 6 to January 8, 1996. This storm was a classic example of a nor'easter, but the storm would not ha ...

, and the January 2016 United States blizzard—are in the Category 5, with a NESIS value higher than 10. The northeast is the first region in the U.S. to use a system that measures the impact of snowfall because it is so densely populated. The scale also allows for meteorologists to predict how long airport delays caused snowstorms will last and when things will become normal afterward. According to Uccellini, NESIS will be used to reevaluate recent snowstorms and measure their impact and not as forecasts such as the ones that are created for hurricanes.

Example

By using an example of the area from Washington D.C. to Boston, a Notable Category 1 snowfall would have to drop anywhere from 4 to 10 inches of snow to fall in the category. A Category 2 would affect same area but more people with more than 10 inches of snow on Mid Atlantic Seaboard. A Category 3 would bring about 10-20 inches of snow and affect millions of people in the process.

Gaps in effectivity

NESIS only takes into account the raw snow totals and impacted population. It does not account for any of the following hazards associated with winter storms. * Blizzard conditions, blowing

, and reduced

visibility The visibility is the measure of the distance at which an object or light can be clearly discerned. In meteorology it depends on the transparency of the surrounding air and as such, it is unchanging no matter the ambient light level or time of ...

in general. *

Gale-force The Beaufort scale is an empirical measure that relates wind speed to observed conditions at sea or on land. Its full name is the Beaufort wind force scale. History The scale was devised in 1805 by the Irish hydrographer Francis Beaufort ...

, storm-force, or even hurricane-force winds and accompanying dangerously low

windchill Wind chill or windchill (popularly wind chill factor) is the lowering of body temperature due to the passing-flow of lower-temperature air. Wind chill numbers are always lower than the air temperature for values where the formula is valid. When ...

temperatures, causing wind damage and

frostbite Frostbite is a skin injury that occurs when exposed to extreme low temperatures, causing the freezing of the skin or other tissues, commonly affecting the fingers, toes, nose, ears, cheeks and chin areas. Most often, frostbite occurs in the han ...

* Freezing rain up to and including

ice storm An ice storm, also known as a glaze event or a silver storm is a type of winter storm characterized by freezing rain. The U.S. National Weather Service defines an ice storm as a storm which results in the accumulation of at least of ice on ex ...

conditions * Sleet, which behaves like a thin layer of quicksand on the road. Cars sink in it or drive across the surface and then slide over the slick individual pellets when attempting to brake. Sleet is very difficult to remove from roads. Due to its self-distributive properties and high weight relative to snow, most snow removal equipment is not suited to the task of removing sleet. Sleet has been referred to as "winter's sand" because when walking across it, kicking it, or picking it up and letting it drop or slide through your fingers, it feels and behaves like sand. * Thundersnow, which, as shown by Chicago's

Groundhog Day blizzard The 2011 Groundhog Day blizzard was a powerful and historic winter storm that affected large swaths of the United States and Canada from January 31 to February 2, 2011, especially on Groundhog Day. During the initial stages of the storm, some me ...

of 2011, can produce small hail and/or combine with destructive blizzard winds to meet the criteria for severe thunderstorms (however, due to public confusion issues related to the connotation of the term "severe thunderstorm", typically associated with heavy rain, very few of these actually prompt a severe thunderstorm warning from the U.S.

) *

Storm surge A storm surge, storm flood, tidal surge, or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low-pressure weather systems, such as cyclones. It is measured as the rise in water level above the n ...

caused by the aforementioned winds on lakes and on the coast and accompanying

wave action In fluid dynamics, a wind wave, water wave, or wind-generated water wave, is a surface wave that occurs on the free surface of bodies of water as a result from the wind blowing over the water surface. The contact distance in the direction of t ...

A theoretical blizzard may only impact enough people with enough snow to rate a category 2 on NESIS, but bring winds of over 70 MPH, paralyzing the region for days as 5–10 foot drifts and windblown debris are removed. Also, NESIS specifically provides for the storm's impact to the entire population of the affected area. This makes it unusable when trying to describe your local conditions caused by a storm.

References

{{Reflist

External links

Overview

Northeast Snowfall Impact Scale
* ScienceDail

January 1, 2007 (accessed 11 Nov 2007) Weather prediction Hazard scales Snow

The Scale

Example

Gaps in effectivity

See also

References

External links