We live in a windy area. The Washoe Zephyr is a wind we can see almost each afternoon during the warmer months. Just like clockwork. While our winds can come out of the west during the winter as well, the Washoe Zephyr is more so driven by temperature differences during the summer. Fire danger can be a problem in our area year round, but the summer heat and wind makes it worse. The Washoe Zephyr can play a huge role in fire danger.
Red Flag Warnings are issued when fire danger is expected to be critical. They are typically issued when the relative humidity is low and wind speeds are strong for a long time. They can also be issued because of thunderstorms. While Red Flag Warnings are not issued every day during the summer months we do experience critical fire danger on a regular basis, even if it’s just for a couple hours. This is because of the Washoe Zephyr.
The Washoe Zephyr sets up in the afternoon and evening hours during the late spring and summer months. Wind is created by differences in pressure, and pressure is related to temperature. The bigger the difference in temperature the stronger the wind will be. On a hot day the central portion of the state really heats up, and warm air rises. This creates low pressure at the surface, as the air rises it is shoved to the west and then forced back down on the western side of the Sierra. Sinking air is associated with high pressure. Wind flows from high pressure to low pressure. We now have a wind coming out of the west.
For example, if it is 90 degrees in Lovelock and 70 in Truckee, we can expect a 30 mile per hour wind gust in the Reno area. The Washoe Zephyr can both improve and lower our air quality. On one hand it can mix up the air and flush out the smoke, but it can also bring more smoke in if there is a fire in California. The wind can also make allergies worse and have an impact on thunderstorms.
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