Editing Santa Ana winds (section)

==Related phenomena==

=== Santa Ana fog ===
A ''Santa Ana fog'' is a derivative phenomenon in which a ground [[fog]] settles in coastal [[Southern California]] at the end of a Santa Ana wind episode. When Santa Ana conditions prevail, with winds in the lower {{convert|2|to|3|km|sp=us}} of the atmosphere from the north through east, the air over the coastal basin is extremely dry, and this dry air extends out over offshore waters of the Pacific Ocean. When the Santa Ana winds cease, the cool and moist [[marine layer]] may re-form rapidly over the ocean if conditions are right. The air in the marine layer becomes very moist and very low clouds or fog occurs.<ref name = "fog1">Leipper, D. F., Fog development at San Diego, California, J. Mar. Research, 7, 337–346, 1948.</ref><ref name = "fog2">Leipper, D. F., Fog on the United States West Coast: a review. Bull. Amer. Meteor. Soc. 75, 229–240.</ref> If wind gradients turn on-shore with enough strength, this sea fog is blown onto the coastal areas. This marks a sudden and surprising transition from the hot, dry Santa Ana conditions to cool, moist, and gray marine weather, as the Santa Ana fog can blow onshore and envelop cities in as quickly as fifteen minutes. However, a true Santa Ana fog is rare, because it requires conditions conducive to rapid re-forming of the marine layer, plus a rapid and strong reversal in wind gradients from off-shore to on-shore winds. More often, the high pressure system over the Great Basin, which caused the Santa Ana conditions in the first place, is slow to weaken or move east across the United States. In this more usual case, the Santa Ana winds cease, but warm, dry conditions under a stationary air mass continue for days or even weeks after the Santa Ana wind event ends.

A related phenomenon occurs when the Santa Ana condition is present but weak, allowing hot dry air to accumulate in the inland valleys that may not push all the way to sea level. Under these conditions auto commuters can drive from the San Fernando Valley where conditions are sunny and warm, over the low Santa Monica Mountains, to plunge into the cool cloudy air, low clouds, and fog characteristic of the marine air mass. This and the "Santa Ana fog" above constitute examples of an air [[inversion (meteorology)|inversion]].

=== Sundowner winds ===
{{main|Sundowner winds}}
The similar winds in the [[Santa Barbara, California|Santa Barbara]] and [[Goleta, California|Goleta]] area occur most frequently in the late spring to early summer, and are strongest at sunset, or "sundown"; hence their name: sundowner. Because high pressure areas usually migrate east, changing the pressure gradient in Southern California to the northeast, it is common for "sundowner" wind events to precede Santa Ana events by a day or two.<ref>{{Cite conference |last1=Ryan |first1=G. |first2=L. E. |last2=Burch |date=1992 |title=An analysis of sundowner winds: A California downslope wind event (Preprints) |conference=Sixth Conf. on Mountain Meteorology |location=Portland, OR |publisher=Amer. Meteor. Soc. |pages=64–67}}</ref>