SIOUX FALLS, S.D. (KELO) — April is the region’s windiest month.
Maybe it shouldn’t come as a surprise after April 2022 when KELOLAND meteorologist Scot Mundt advised the public on April 5 to “get used the strong wind.” Numerous wind advisories, high wind warnings and high wind watches were in effect on April 5 and April 6. Western South Dakota was expected to have gusts of more than 60 miles per hour on April 5.
It’s 2023, the wind has been around for the past several days and it’s going to stick around for a while, Mundt said on Wednesday. Why is April so windy and why have the past several days been so windy?
“The easy answer is, it’s the changing of the season,” Mundt said.
Mundt pointed out the 90-degree day some parts of the region had last week.
“Now, we are back to below average temperatures,” Mundt said.
“Unfortunately, April is our windiest month just because Mother Nature is trying to balance itself out and trying to bring in the warmer spring months,” Mundt said. “It does that through wind and through weather.”
Wind recordings from the past seven days show some high gusts in the state.
On April 16, the South Dakota State University Mesonet site at Beresford recorded at gust of 53 mph. A 50 mph gust was recorded on April 13 and a 45 mph gust was recorded on April 18.
Sioux Falls had a wind gust of 41 mph on April 16 and a gust of 37, according to the Mesonet.
In western South Dakota, Union Center had a wind gust of 39 mph on April 18.
Wind gusts could be more than 40 mph by Thursday, Mundt said
Air pressure is also part of wind.
“Wind is a factor of the difference in (air pressure). The difference in low pressure and difference in high pressure,” Mundt said.
The National Oceanic and Atmospheric Administration (NOAA) describes wind as when gases move from high-pressure areas to low-pressure areas. The larger the difference between the pressures, the faster the air will move from the high to the low pressure.
“When we get on the backside of high pressure, when that’s to our southeast, we get a nice southerly wind and those south winds help us warm,” Mundt said. “Usually when we are ahead of a low pressure system coming in from the west, they like to bring in our stormy conditions. Then, we’ll also get asoutherly wind. When that storm system moves away from us, then we are on the backside of low pressure, which means we will start to get this north wind.”
“What’s happening here over the next week or two is we’ll have a low pressure system more or less set up camp in Hudson Bay (Canada),” Mundt said.
That low pressure system in Canada will cause north winds in the region with below average temperatures, he said.
The forecast for wind is in steady speeds such as 20 to 25 mph but also in gusts.
Gusts happen when there are slight differences in air pressure and temperatures in a system, Mundt said. The wind can be steady but can get caught in those differences, which can cause the gusts. Stronger areas of low pressure creates strong winds, gusty winds with that as well.
The weather on this Friday, April 21, is predicted to have high wind gusts, Mundt said.
Various historical weather data show that high winds aren’t new for April.
Ten years ago, the highest wind gust in Aberdeen was 32.22 mph, according to the Farmers Almanac. The maximum sustained wind speed was 24.17 mph.
While science has a major role in the wind so does the landscape, Mundt said.
The plains of the region is a landscape in which there is not much to slow down or stop the wind, Mundt said. Unlike areas with lots of woods, take northern Wisconsin with its trees, as an example.
The wind will slow down as May arrives and the summer months follow, Mundt said.
The summer months tend to be the least windy with August the least windy, Mundt said.