The "Ridiculously Resilient Ridge", sometimes shortened to "Triple R" or "RRR", is the nickname given to a persistent

anticyclone An anticyclone is a weather phenomenon defined as a large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere as viewed from abov ...

that occurred over the far northeastern

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

, contributing to the

2011–2017 California drought The 2011–2017 California drought persisted from December 2011 to March 2017 and consisted of the driest period in California's recorded history, late 2011 through 2014. The drought wiped out 102 million trees from 2011 to 2016, 62 million of tho ...

. The "Ridiculously Resilient Ridge" nickname was originally coined in December 2013 by Daniel Swain on the Weather West Blog, but has since been used widely in popular media as well as in

peer-reviewed Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work (peers). It functions as a form of self-regulation by qualified members of a profession within the relevant field. Peer review ...

scientific literature.

Features

The Ridiculously Resilient Ridge was characterized by a broad region of anomalously positive

geopotential height Geopotential height or geopotential altitude is a vertical coordinate referenced to Earth's mean sea level, an adjustment to geometric height (altitude above mean sea level) that accounts for the variation of gravity with latitude and altitude. Thu ...

on monthly to annual timescales. This persistent high pressure system acted to "

block Block or blocked may refer to: Arts, entertainment and media Broadcasting * Block programming, the result of a programming strategy in broadcasting * W242BX, a radio station licensed to Greenville, South Carolina, United States known as ''96.3 ...

" the prevailing mid-latitude

westerlies The westerlies, anti-trades, or prevailing westerlies, are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude. They originate from the high-pressure areas in the horse latitudes and trend to ...

, shifting the storm track northward and suppressing

extratropical cyclone Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of ...

(winter storm) activity along the West Coast of the United States. Such a pattern is similar to—but of greater magnitude and longevity than—atmospheric configurations noted during previous California droughts.

Associations

This anomalous atmospheric feature disrupted the North Pacific

storm track ''Storm Track'' was the first magazine for and about storm chasing. The magazine was in circulation between 1977 and 2002. History and profile ''Storm Track'' was started in 1977 by chasing pioneer David Hoadley following an informal meeting o ...

during the winters of 2012/13, 2013/14, 2014/15, resulting in extremely dry and warm conditions in

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

and along much of the West Coast. The Ridge comprised the western half of a well-defined atmospheric ridge-trough sequence associated with an unusually amplified "North American winter dipole" pattern, which brought persistent anomalous cold and precipitation to the eastern half of North America in addition to record-breaking warmth and drought conditions in California. This ridge of high pressure was also associated with a blob of high water temperatures in the Pacific Ocean, which resulted in substantial warming along the western coast of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

as well as adverse ecological impacts. However, it is generally thought that "

The Blob ''The Blob'' is a 1958 American science fiction horror film directed by Irvin Yeaworth, and written by Kay Linaker and Theodore Simonson. It stars Steve McQueen (in his first feature film leading role) and Aneta Corsaut and co-stars Earl Rowe a ...

" of warm ocean water was caused by the persistence of the ridge and subsequent reduction in vertical ocean mixing due to storms, rather than the reverse. On the other hand, recent research suggests that unusual oceanic warmth in the western tropical Pacific Ocean may have played a role in triggering and maintaining the Triple R over successive seasons. High amplitude atmospheric ridge patterns similar to the Triple R have occurred more frequently in recent decades and there is evidence that the occurrence of persistent North Pacific geopotential height anomalies and anomalously dry California winters, will increase due to global warming, although uncertainty remains regarding the magnitude of these future changes.

References

{{Authority control Anticyclones 2013–14 North American winter 2014–15 North American winter 2015–16 North American winter Anomalous weather

Features

Associations

See also

References