Editing Santa Ana winds (section)

===Regional impacts===
[[File:Satellite image of Thomas Fire.jpg|thumb|The [[Thomas Fire]] and two other fires burn out of control near [[Ventura, California|Ventura]] in December 2017, with a strong Santa Ana wind driving the flames toward the coast and blowing the smoke offshore.]]
Santa Ana winds often bring the lowest [[relative humidity|relative humidities]] of the year to coastal Southern California. These low humidities, combined with the warm, compressionally-heated [[air mass]], plus the high wind speeds, create critical fire weather conditions. The combination of wind, heat, and dryness accompanying the Santa Ana winds turns the [[chaparral]] into explosive fuel feeding the infamous [[wildfire]]s for which the region is known. 

Although the winds often have a destructive nature, they have some benefits as well. They cause cold water to rise from below the surface layer of the ocean, bringing with it many nutrients that ultimately benefit local fisheries. As the winds blow over the ocean, [[sea surface temperature]]s drop about 4[[°C]] (7[[°F]]), indicating the [[upwelling]]. [[Chlorophyll]] concentrations in the surface water go from negligible, in the absence of winds, to very active at more than 1.5 milligrams per cubic meter in the presence of the winds.<ref name="Vasquez2008" />

====Local maritime impacts====
During the Santa Ana winds, large ocean waves can develop. These waves come from a northeasterly direction toward the normally sheltered sides of the [[Channel Islands, California|Channel Islands]], including commonly visited [[Santa Catalina Island, California|Catalina]] and [[Santa Cruz Island|Santa Cruz]] islands. Normally well-sheltered harbors and anchorages such as [[Avalon, California|Avalon]] and [[Two Harbors, California|Two Harbors]] can develop high surf and strong winds that can tear boats from their moorings. During Santa Ana conditions, it is advised that boaters moor on the Southern side of affected islands or return to the mainland.<ref>Fagan, 2002, The Cruising Guide to Central and Southern California (International Marine)</ref>