A sundowner is a northerly

offshore wind Offshore wind power or offshore wind energy is the generation of electricity through wind farms in bodies of water, usually at sea. There are higher wind speeds offshore than on land, so offshore farms generate more electricity per amount of c ...

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 ...

along the southern Pacific slope of

Santa Ynez Mountains The Santa Ynez Mountains are a portion of the Transverse Ranges, part of the Pacific Coast Ranges of the west coast of North America. It is the westernmost range in the Transverse Ranges. The range is a large fault block of Cenozoic age create ...

, in communities along the

Gaviota Coast The Gaviota Coast in Santa Barbara County, California is a rural coastline along the Santa Barbara Channel roughly bounded by the city of Goleta on the south and the north boundary of the county on the north. This last undeveloped stretch of ...

and Santa Barbara towards but not including

Ventura County Ventura County () is a County (United States), county in Southern California, the southern part of the U.S. state of California. As of the 2020 United States Census, 2020 census, the population was 843,843. The largest city is Oxnard, California ...

Formation

It occurs when a region of high pressure is directly north of the area, the coast of which trends east–west. This contrasts with the more typical onshore flow. The winds blow with greatest force when the

pressure gradient In atmospheric science, the pressure gradient (typically of air but more generally of any fluid) is a physical quantity that describes in which direction and at what rate the pressure increases the most rapidly around a particular location. The ...

is perpendicular to the axis of the Santa Ynez Mountains, which rise directly behind Santa Barbara. These winds often precede Santa Ana events by a day or two, but also as tail end of Santa Anas after they weaken, it is normal for high-pressure areas to migrate east, causing the pressure gradients to shift to the northeast. Aptly named sundowners are typically nighttime events that terminate after sunrise, they may repeat for days, while Santa Anas are multi-day long events. Weaker sundowner effects may occur without an associated Santa Ana event, at times due to a

Diablo wind Diablo wind is a name that has been occasionally used for the hot, dry wind from the northeast that typically occurs in the San Francisco Bay Area of Northern California, during the spring and fall. The same wind pattern also affects other parts ...

event (Northern California), akin to a

foehn A Foehn or Föhn (, , ), is a type of dry, relatively warm, downslope wind that occurs in the lee (downwind side) of a mountain range. It is a rain shadow wind that results from the subsequent adiabatic warming of air that has dropped most of i ...

wind.

Fire dangers

Sundowners are particularly dangerous during

wildfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identi ...

season because the air heats and dries as it descends from the mountains to the sea. Gale force hot, dry winds can make firefighting impossible. A sundowner quickly burned a swath from the mountains through populated areas and across

Highway 101 Highway 101 was an American country music band founded in 1986 in Los Angeles, California. The initial lineup consisted of Paulette Carlson (lead vocals), Jack Daniels (guitar), Curtis Stone (bass guitar, vocals), and Scott "Cactus" Moser (dru ...

into Hope Ranch during the 1990 Painted Cave Fire. The most intense periods of the

Jesusita Fire The Jesusita Fire was a wildfire that started on May 5, 2009 in the hills of Santa Barbara, California in the western United States. By the time the fire was contained on May 18 it had burned , destroyed 80 homes and damaged 15 more before being ...

's destruction have also been blamed on sundowner winds. The Sherpa Fire grew to overnight due to the sundowner winds, destroying the water system for El Capitán State Beach at the beginning of the 2016 fire season.

Origin

The etymology of the word ''sundowner'' is uncertain, but it may derive from the

Spanish Spanish might refer to: * Items from or related to Spain: ** Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Ca ...

term ''

zonda Zonda may refer to: * Pagani Zonda, a mid-engine sports car * Zonda (horse), retired New Zealand Thoroughbred racehorse * Zonda Department, an administrative subdivision of San Juan Province in Argentina * Zonda Home, a publisher of data relate ...

,'' or from the

Arabic Arabic (, ' ; , ' or ) is a Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C. E.Watson; Walte ...

simoom Simoom ( ar, سموم ''samūm''; from the root ''s-m-m'', "to poison") is a strong, hot, dry, dust-laden wind. The word is generally used to describe a local wind that blows in the Sahara, Israel, Palestine, Jordan, Iraq, Syria, and the d ...

'', which are both similar wind phenomena. It is also typically the case that sundowner winds commence in the evening near sunset, when onshore sea breezes abate and offshore flows such as the sundowners pick up.

References

Winds Climate of California Natural history of Santa Barbara County, California Santa Ynez Mountains Santa Barbara, California Weather events in the United States {{climate-stub

Formation

Fire dangers

Origin

See also

References