The North Pacific High is a semi-permanent,

subtropical The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° north a ...

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 ...

located in the northeastern portion of the

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 conti ...

, located northeast of

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

and west of

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

. It is strongest during the northern hemisphere summer and shifts towards the equator during the winter, when the

Aleutian Low The Aleutian Low is a semi-permanent low-pressure system located near the Aleutian Islands in the Bering Sea during the Northern Hemisphere winter. It is a climatic feature centered near the Aleutian Islands measured based on mean sea-level press ...

becomes more active. It is responsible for California's typically dry

summer Summer is the hottest of the four temperate seasons, occurring after spring and before autumn. At or centred on the summer solstice, the earliest sunrise and latest sunset occurs, daylight hours are longest and dark hours are shortest, wit ...

and fall and typically wet

winter Winter is the coldest season of the year in polar and temperate climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Different cultur ...

and

spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of water * Spring (mathematics), a geometric surface in the shape of a h ...

, as well as Hawaii's year-round

trade winds The trade winds or easterlies are the permanent east-to-west prevailing winds that flow in the Earth's equatorial region. The trade winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisp ...

. During 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 North Pacific High persisted longer than usual, due to a mass of warm water in the Pacific Ocean, resulting in the Ridiculously Resilient Ridge. This significantly limited the number of powerful winter storms that were able to reach

, resulting in historic drought conditions in that state for several years.

References

External links

* * {{Cyclones Regional climate effects Pacific Ocean Anticyclones

See also

References

External links