A Gulf low or Texas Low is a

low pressure area In meteorology, a low-pressure area (LPA), low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. It is the opposite of a high-pressure area. Low-pressure areas are commonly associated with inclem ...

that forms or intensifies over the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

and moves northeast on the western side of the

Appalachian Mountains The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain ...

and sometimes on the Atlantic coast to become a

nor'easter A nor'easter (also northeaster; see below) is a large-scale extratropical cyclone in the western North Atlantic Ocean. The name derives from the direction of the winds that blow from the northeast. Typically, such storms originate as a low ...

. Because they move from over or near the Gulf of Mexico, these storm systems are capable of transporting copious amounts of moisture with them. At their strongest, these storm systems are even more potent snowfall producers than

panhandle hook A panhandle hook (also called a pan handle hook or Texas hooker) is a relatively infrequent winter storm system whose cyclogenesis occurs in the South to southwestern United States from the late fall through winter and into the early spring months ...

s, primarily because of the mixing of Atlantic Ocean moisture into the storm system once they cross the Appalachian Mountains. Because of the general west to east movement of weather systems in the mid latitudes of the northern hemisphere, Gulf Lows rarely affect areas west of the

Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

. One such exception was the Halloween Blizzard of 1991.

Types

There are two types of "Gulf Lows": West and East Gulf Cyclones or Types Ga and Gb.as per the

California Institute of Technology The California Institute of Technology (branded as Caltech) is a private research university in Pasadena, California, United States. The university is responsible for many modern scientific advancements and is among a small group of institutes ...

(CIT) As western storms (

Alberta clipper An Alberta clipper, also known as an Alberta low, Alberta cyclone, Alberta lee cyclone, Canadian clipper, or simply clipper, is a fast-moving low-pressure system that originates in or near the Canadian province of Alberta just east of the Rocky ...

s, North and South Pacific and Rocky Mountain) move eastward, a trailing frontal remnant is often left in the Gulf of Mexico or the adjacent coastal states. When the frontal trough from a new cyclone enters this area,

cyclogenesis Cyclogenesis is the development or strengthening of Cyclonic rotation, cyclonic circulation in the atmosphere (a low-pressure area). Cyclogenesis is an umbrella term for at least three different processes, all of which result in the development of ...

often occurs on the Gulf front. This newly formed Gulf wave that moves northeastward and dominates the weather over the eastern United States and Canada. One of the basic differences between the two types is that the Ga track is west of the Appalachians and the Gb track is east of the Appalachians.

Ga

The Ga type is characterized by an upper-level trough in the central and eastern part of the United States which steers the newly formed wave north and northeast over the western side of the Appalachians accompanied by widespread precipitation to the north. This type is most frequently observed in the winter and early spring.

Gb

The 1993 North American Storm Complex started out as a Gulf Low (East Gulf Low or Gb) before it eventually evolved into a

. It initially formed in the western Gulf of Mexico and moved towards Florida before turning to the north and becoming a nor'easter. Another large gulf low storm was the

Great Blizzard of 1978 The Great Blizzard of 1978, also known as the Cleveland Superbomb, was a historic winter storm that struck the Ohio Valley and Great Lakes regions of the United States as well as Southern Ontario in Canada from Wednesday, January 25 through F ...

, which brought one of the lowest non-tropical barometric pressures recorded in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

References

{{Cyclones Extratropical cyclones fr:Tempête synoptique continentale américaine#Dépression du Golfe du Mexique

Types

Ga

Gb

See also

References