If you spend any length of time outside in the spring, one of the hardest things to deal with is often the wind. We do have a rather breezy climate in Wisconsin during the spring. When temperatures are on the cool side, you notice it right away. When you try to garden, mow lawn, fish, or take a bike ride it’s the first thing that gets your attention. Last week the strong wind combined with very dry top soil created brown clouds and dust storms in central Wisconsin. Many people have commented to me about the wind this spring. I’m not exactly sure if it’s because it seems worse than usual, or just because people in general spend less time outdoors now than they used to. Therefore when they do go out for an activity they are very sensitive to it.
I have read some studies that have shown a detectable increase in average winds over Lake Superior in the last 30 years, but I haven’t seen one directly for our part of Wisconsin. I pulled up wind speed numbers for April and May this year to give you a quantitative idea of where we stand. In April in the Wausau area we had 26 days with winds reaching at least 10 mph and 14 days with winds topping out at 20 mph or higher. In May we had 27 days where winds hit the 10 mph threshold and 17 days with winds over 20 mph. Of course there were a few days mixed in with 30 mph+ gusts. So at first blush that does seem like quite a few breezy days.
Spring is often windy because the jet stream is active yet, sending fronts and low pressure systems frequently through the northern U.S. The pressure gradient is often strong and thus the air is getting squeezed in many different directions. Also the higher sun angle and deeper heating of the boundary layer causes the air to mix to greater height. This in turn easily transfers momentum from aloft down to the ground enhancing the wind. If you don’t like all the wind the good news is that it gradually decreases as we head into summer. The jet stream gets weaker and lifts north of Wisconsin normally. Fronts are less common as well. So there will be more “calm” days mixed in over the next few months. Of course on the negative side, those are the days that often feel stifling hot without the refreshing breeze. I guess you can’t have it all.
This post was written by Tony Schumacher on May 30, 2012