# Miller classification > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Miller_classification > Markdown URL: https://mediated.wiki/source/Miller_classification.md > Source: https://en.wikipedia.org/wiki/Miller_classification > Source revision: 1336051963 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Classification system for Nor'easters}} [[File:1993 storm century.jpg|thumb|The [Superstorm of 1993](/source/1993_Storm_of_the_Century), a classic Miller type A nor'easter]] The '''Miller classification''' is a technique that [meteorologist](/source/meteorologist)s use to classify [nor'easter](/source/nor'easter)s. The system splits nor'easters into five categories: Miller A, Miller B, Miller C, Miller D, and Miller E; the classification system initially started out with the first two categories.{{cite web|title=The Miller Classification|date=December 4, 2020|last=Priante|first=Mike|url=https://weatherworksinc.com/news/Miller-A-vs-Miller-B|publisher=WeatherWorks Inc.|access-date=December 11, 2020}} The system was derived by meteorologist and researcher J.E. Miller in 1946, (not to be confused with [R.C. Miller](/source/Robert_C._Miller), the [Air Force](/source/U.S._Air_Force) meteorologist who, in 1948, made the [world's first successful tornado forecast](/source/1948_Tinker_Air_Force_Base_tornadoes)). ==Background== A nor'easter is a macro-scale [extratropical cyclone](/source/extratropical_cyclone) that travels along the [East Coast of the United States](/source/East_Coast_of_the_United_States) and [Atlantic Canada](/source/Atlantic_Canada). The cyclones are called nor'easters because the winds over the coastal area are typically from the northeast.{{cite web|title=What is a Nor'easter?|url=https://www.weather.gov/safety/winter-noreaster|publisher=National Weather Service|access-date=December 11, 2020}} These storms may occur at any time of year, but are most frequent and severe between September and April. Nor'easters usually develop in the latitudes between [Georgia](/source/Georgia_(U.S._state)) and [New Jersey](/source/New_Jersey), within 100 miles east or west of the coastline. These storms track north-northeastward and typically attain peak intensity between [New England](/source/New_England) and the [Maritime Provinces of Canada](/source/Atlantic_Canada).{{cite news|title=What is a Nor'easter?|publisher=The Weather Channel|author=Brian Donegan|date=March 1, 2018|url=https://weather.com/science/weather-explainers/news/noreaster-snow-rain-wind-northeast-explainer|access-date=December 11, 2020}} The cyclones produce precipitation in the form of heavy rain or snow, or a mix of both, along with [gale](/source/gale)-force winds. The storms can cause heavy damage in populated cities, such as [Washington D.C.](/source/Washington_D.C.), [Baltimore](/source/Baltimore), [Philadelphia](/source/Philadelphia), [New York City](/source/New_York_City), and [Boston](/source/Boston). This is possibly due to the fact that the cyclones undergo [bombogenesis](/source/bombogenesis) as they travel along the coast, causing severe conditions from high winds and heavy precipitation.{{cite news|title=Latest big winter storm powered by 'bombogenesis'|date=March 13, 2019|url=https://www.noaa.gov/stories/latest-big-winter-storm-powered-by-bombogenesis|publisher=National Oceanic and Atmospheric Administration|access-date=December 11, 2020}} ==Description== {{multiple image | align = left | direction = vertical | width = 150 | image1 = MillerTypeA.gif | alt1 = | image2 = MillerTypeB.gif | alt2 = | footer = Diagrams of the Miller classifications: type A (top) and type B (bottom) }} The Miller classification was created by meteorologist and researcher J.E. Miller in 1946. Meteorologists use the technique to determine the track and severity of nor'easters. Storms that receive the type A classification develop primarily in the [Gulf of Mexico](/source/Gulf_of_Mexico) or along the southern East Coast, near Georgia and [South Carolina](/source/South_Carolina). These storms develop primarily on the Gulf Coast or East Coast along a decaying [cold front](/source/cold_front), or along the marine/land [air mass](/source/air_mass) contrast found on the East Coast.{{cite report|title=Types of Storms that Typically Produce Heavy Snow in PA|url=https://www.weather.gov/ctp/SnowStormTypes#MillerAMap|publisher=National Weather Service State College, Pennsylvania|access-date=December 11, 2020}} Miller A systems then [quickly deepen](/source/Explosive_cyclogenesis) and intensify as they move northeastward. Type A storms typically move rapidly, hitting the [Mid-Atlantic United States](/source/Mid-Atlantic_United_States) the hardest. Nevertheless, New England can still receive significant snow depending on the system's intensity. The [Superstorm of 1993](/source/Superstorm_of_1993) is considered to have been a Miller Type-A storm.{{cite web|title=Mid-Atlantic Winter Storm Patterns|author=Tony Siebers|url=https://glenallenweather.com/alink/18snow/stormtypes.htm|publisher=Glen Allen Weather|access-date=December 11, 2020}} Storms that receive the type B classification develop inland over the United States. Storms that come in from the west (up the Ohio Valley) are usually referred to as "Miller Type-B" storms. These storms originate as an [area of low pressure](/source/area_of_low_pressure) creating storming weather over the [Midwestern United States](/source/Midwestern_United_States) and the [Ohio River Valley](/source/Ohio_River_Valley). These storms have a defined [low-level circulation center](/source/low-level_circulation_center) that moves toward the [Appalachian Mountains](/source/Appalachian_Mountains) from the west. As these storms approach the mountains, they lose their defined circulation center due to high terrain. A more powerful cyclone spins up along the warm [Gulf Stream](/source/Gulf_Stream) waters off the coast of North Carolina. When this re-development occurs, the storm produces precipitation, including heavy snow, along the inland parts of the Mid-Atlantic. After redevelopment, the nor'easter takes a northerly track, then turns out to sea near New England. An example of this storm is the [February 5–6, 2010 North American blizzard](/source/February_5%E2%80%936%2C_2010_North_American_blizzard). ===Additional classification types=== A study written by Albright and Cobb (2004) showed that there are five predominant patterns that produce four inches or more of snowfall across the Mid-Atlantic. They added classification types C through E, adding onto the Miller classification. {{clear}} ==See also== {{Portal|Weather|North America}} * [Regional snowfall index](/source/Regional_snowfall_index) * [Extratropical cyclone](/source/Extratropical_cyclone) * [Cyclogenesis](/source/Cyclogenesis) ==References== {{reflist}} Category:Meteorological concepts Category:Weather prediction Category:Hazard scales --- Adapted from the Wikipedia article [Miller classification](https://en.wikipedia.org/wiki/Miller_classification) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Miller_classification?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.