While we don’t see a lot of rain and snow in northern Nevada, we do see a lot of wind. The summer season can be windy, especially in the late afternoon and evening hours. The Washoe Zephyr is a type of wind specific to our area, and was named by Mark Twain.
Strong winds enhance fire danger and can make fires grow in size and spread. While most of the day might be calm with light winds, it’s common for wind speeds to pick up in the late afternoon and evening increasing fire danger for a couple hours. The Washoe Zephyr is a west wind that can produce wind gusts typically between 20 to 30 miles per hour. While this is enough wind to increase fire danger, the National Weather Service typically issues Red Flag Warnings for slightly stronger and longer lasting wind events. Even if a Red Flag Warning has not been issued, we should still be fire aware-- especially when the Washoe Zephyr kicks in.
The Washoe Zephyr develops east of the Sierra, including places like Reno, Carson City, Fernley, and Pyramid Lake.
So how does the Washoe Zephyr form? It all has to do with temperature and pressure differences. The stronger the temperature difference, the stronger the wind will be. As temperatures warm east of Reno an area of low pressure forms, because warm air rises. As the air rises, it eventually gets displaced and sinks on the other side of the Sierra. This is called high pressure. Wind flows from high to low pressure. Now you have it a west wind during the summer season. According to the National Weather Service, when Truckee is sitting at 70 degrees and Lovelock is 20 degrees warmer, it is a big enough temperature difference to produce a 30mph wind gust in the Truckee Meadows.
The Washoe Zephyr can either make our air quality worse because of nearby fires, or it can make it better. If a fire is located to our west in California, the Washoe Zephyr can bring in the smoke, but if the wind is strong enough it can also flush out the smoke. If a wind storm is already moving through, the Washoe Zephyr will only make things worse.
