There are a variety of reasons why wind speeds are usually stronger up in the mountains than in the valley. The best way to explain it is in the mountains you are more so surrounded by free air. Being higher up lowers the impact of forces such as friction. You are also closer to the jet stream where wind speeds top 100 miles per hour on almost a regular basis.
Trees, rocks, grass, and roads all plays a role in slowing the air down by increasing friction. The more the surface area the more friction there is and friction slows down wind speeds. There is a simple way to show this. All you need is a couple pieces of paper. Crumple one and leave the other one as is. Next drop them from a tall structure. The one with less surface area will fall faster.
If you drive through a mountain pass the wind speeds could be stronger there as well, because the air is moving through a smaller space.
During a winter storm it is not unheard of for wind speeds to top 100 miles per hour in the mountains. In our area, if the flow comes out of the northeast the wind speed accelerates on the other side of the mountain. Just like riding a roller coaster. This played a role in what happened this past weekend. Wind speeds were higher on the west side of Tahoe opposed to the east.
Over the years we’ve seen some pretty impressive wind speeds in the mountains. We’ve seen wind speeds well over 100 miles per hour not only throughout the country, but in the Sierra as well. Ward Mountain in Alpine Meadows had a gust of 199 miles per hour back in 2017 and just this past weekend Alpine Summit reached 125 miles per hour. Mammoth Mountain reached 111. While we can get strong winds in the valley too, it is more common in the mountains.
A category five hurricane has wind speeds over 156 miles per hour. This past weekend the observation site at Kirkwood recorded a wind gust of 209 miles per hour. If verified, it would break the all time record for strongest wind gust in California. But there is some speculation that it could have been an error.
