It’s not just you: This is the windiest month in decades

If it feels like the wind just won’t let up, you’re right.

Through April 24, Sioux Falls has averaged wind speeds of 16.1 mph. That beats the previous record of 13.7 mph set in April 2014 “by a large margin,” said meteorologist and science operations officer Phil Schumacher with the National Weather Service.

“So you’re looking at beating the previous high of the last 25 years by over two miles an hour, which is impressive.”

The National Weather Service can look at wind speeds as far back at 1996, when it began measuring them with the current approach.

Since the beginning of the year, there have been 35 days in Sioux Falls with gusts exceeding 40 mph and 12 days when it gusted to more than 50 mph. Twenty of the 35 and eight of the 12 have been since March 1.

“April is typically the windiest month of the year,” Schumacher said. “And March is typically the second windiest month, so it’s not unusual that it’s windy. It’s just even more than normal.”

What’s happening

So what’s going on?  A few things.

At the start of the year, storms were tracking north across North Dakota and into Minnesota and Wisconsin, “so we typically could get strong winds for usually a day,” Schumacher said.

“But since March, the storm track has changed and especially in April where it’s coming more out of Colorado and Wyoming and heading north, and we tend to get strong south winds ahead of those and strong northwest winds behind them, and over the last couple weeks, those storm systems have been moving very slow.”

That means we’ve seen wind for a day or two ahead of a storm system and then for two or three days after it, he said.

The ongoing dryness isn’t helping either.

“When you have water on the ground, the sun’s energy hits the ground, and some of it is used to evaporate the water, which means there’s less energy available to warm the atmosphere,” Schumacher explained.

With nothing to evaporate, the sun’s energy instead warms up the atmosphere to the point that winds can come down from higher levels than if it were wet out.

“It’s a marginal thing,” Schumacher said. “You still need a strong low pressure system, but it can add to the gusts. So instead of gusts at 50 to 55, you’re getting gusts at 60 to 65.”

How long can it last?

The long-term outlook is less certain, but there are some encouraging signs ahead once this week is over.

“The remainder of this week and into early next, it will be somewhat windy, but after that it looks like we start getting into more of a late-spring pattern, which means you can still get rain and a day of wind, but things move fast, and they’re not as strong,” Schumacher said.

“Instead of those systems that give blizzards to western North Dakota, these are weaker, and that’s normal.”

Summer is the least windy time of year, he added.

And while April temperatures are trending about 3 degrees below normal, and May is favored to be slightly below normal, “you get into summer, and it switches to above-normal temperatures, and unfortunately we’re looking at below-normal precipitation for May and at least the early part of summer,” he said.

“We need an all-day rain for an inch or so, and we haven’t had that all year, which is another reason it’s windy.”