Abstract

Santa Lucia winds are a newly-discovered downslope wind phenomenon that can cause an increase in temperatures and damaging wind gusts for central California’s San Luis Obispo (SLO) County. These offshore wind gusts can exacerbate fire weather conditions by reducing relative humidity and producing high temperatures and strong wind gusts, increasing SLO County’s vulnerability to destructive wildfires. Understanding the parameters for identifying Santa Lucia wind events can help forecasters at the National Weather Service Los Angeles/Oxnard (NWS-LOX) office better assist fire partners in SLO County. To determine these parameters, we analyzed high-resolution data from the past four years (2021-2025), including relative humidity, temperature, wind speed, wind gusts, and wind direction on event days. These datasets were used to find a mean weather pattern for high impact Santa Lucia wind days. This study produced a climatological database of past Santa Lucia wind events, showing how these winds are similar to previously-studied Santa Ana winds in Southern California and Diablo winds in the San Francisco Bay Area. Like these wind systems, Santa Lucia winds occur most frequently during cooler months. However, events that take place during hotter months result in a lower relative humidity, increasing SLO County’s vulnerability to damaging fires. This information can be used by fire agencies and other partner agencies to improve deployment measures and increase community awareness of fire risks.