Learn More. Offshore winds in Southern California are winds that move from the interior land towards the coast from east to west. These winds can develop as a result of the uneven daily warming over land and water. Land breezes can certainly fan the flames of fires already burning—for instance, the recent Bobcat Fire. Santa Ana winds are a specific type of offshore wind, and it turns out there is more than one accepted definition of Santa Ana winds.
The American Meteorological Society says Santa Ana winds are driven by strong pressure gradients that develop from surface high pressure over the Great Basin. From a wildfire perspective, another widely accepted interpretation of Santa Ana winds states that they occur in any synoptically driven wider pattern offshore wind event that results in warming and subsequent drying in the western side of the Southern California mountain ranges.
Pressure imbalances drive wind in the atmosphere as air tries to reach an equilibrium and stabilize, which will never fully happen. Air moves from high to low pressure while trying to stabilize and the stronger the pressure difference, the stronger the wind. We call this difference in pressure a pressure gradient.
The tighter the packing of isobars, the stronger the pressure gradient. The windstorms can last for several days on end. Similar weather events occur in the U.
In January , U. One of the strongest Santa Ana events in weather history occurred in December During this event, locations in the San Gabriel Valley, including Pasadena, CA, were pummeled by 97 mph windspeeds and gusts of up to mph! But more importantly, the heat, dryness, and strong winds can exacerbate fire weather conditions during peak wildfire season in the western United States. During a late October Santa Ana event, meteorologists forecast wind gusts of 80 mph for locations across the Southern California region.
Tiffany Means is a freelance writer and a degreed meteorologist. She specializes in weather forecasting and enjoys making the subject of weather and the science behind it more relatable. Moon Phase Calendar. In addition, their dry conditions increase the risk of wildfires in the area.
Santa Ana Winds occur when air from a region of high pressure over the dry, desert region of the southwestern U. This creates dry winds that flow east to west through the mountain passages in Southern California. These winds are most common during the cooler months of the year, occurring from September through May.
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