SIOUX CITY, Iowa (KCAU) — If you didn’t know, Monday was the first day of spring. Officially beginning at 4:24 PM Monday, March 20th, the March equinox occurs when the sun crosses over the equator resulting in slightly more daylight hours than nighttime hours.
However, a common misconception is that day and night are equal lengths on the first day of spring, however, with the spring equinox, this occurs a few days prior to the first day of spring and is called the equilux and not actually on the day of the spring equinox. For the autumnal equinox it occurs a few days after the equinox.
Both the spring equinox and autumnal equinox also feature the fastest sunsets (the total amount of time it takes the sun to sink below the horizon) of the year. This is because the sun rises due east and sets due west, meaning the setting sun is at it’s steepest angle of the year, and the steeper the angle between due west and the setting sun (for reference the sun angle in Sioux City today for sunrise was 89° E and for sunset, 271° W), the quicker the sun sets. Sunsets gradually lengthen through the next few months and the longest sunset takes place during the solstices (summer & winter).
And know you’re probably thinking, “Ok. Cool. But how is our spring looking? Will we finally see warmer weather return? Are we going to get more rain and finally get relief from this drought we’re in?”
The answers to those questions are…
According to the National Oceanic and Atmospheric Administration (NOAA), and the National Weather Service (NWS), La Nina is officially over after 2+ years of the cycle of cooler than normal ocean temperatures in the eastern/central Pacific Ocean that typically results in drought conditions in the southern US and heavy rains and flooding in the the Pacific NW and Canada. For us here in Siouxland, this has brought drier and cooler winters and drier overall conditions throughout the year, resulting in moderate to exceptional drought conditions persisting throughout Siouxland over the span of the past three years or so.
Now NOAA says the transition to El Nino is underway and likely to persist through the next few months into early summer, with the development of El Nino increasingly likely sometime after that.
So, what does this mean for our spring?
Unfortunately, drought conditions are expected to continue, however, because we have equal chances of seeing above average precipitation or below average precipitation, we could potentially see some improvements with those drought conditions if we do end up leaning towards a wetter than normal pattern over the next few months.
These drought conditions do however, fortunately, mean our spring flood risk is extremely low for the majority of Siouxland with just a few areas in our South Dakota viewing area having a minor/moderate risk of spring flooding. These flood risks are produced by the National Water Center, with NOAA’s hydrologic assessment of current snowpack, drought conditions, soil saturation levels, frost depth, streamflow, and precipitation.
We also have an equal chance of seeing either above or below average temperatures this spring.
For the latest weather updates, visit KCAU 9’s Weather page by clicking here.
And with winter hitting Siouxland, it pays to be prepared. For a variety of resources, click here.