East winds event of March 2019: the anomalous occurrence and wildfire impacts

The March 2019 East Winds event in Western Washington and the associated increased wildfire activity was very anomalous for the region and the time of year. In a three-day period, temperatures were about 20 to 30 degrees Fahrenheit above climatic normal temperatures and many maximum temperatures were broken. Low relative humidity values combined with strong easterly winds created unseasonably warm and dry conditions in the normally temperate forested regions of Western Washington. During that same three-day period, firefighters responded to 49 wildfires west of the Cascades, which is more than all the combined March wildfires in Western Washington for the previous ten years. Mapping these wildfires, their proximity to the Wildland Urban Interface (WUI), and some of the extreme meteorological conditions and climatic abnormalities that contributed to its anomalous nature are useful to improve understanding and forecasts for future events. Doing so will aid in the prevention of future wildfire outbreaks in dense forested regions during downslope wind events.