SIOUX CITY, Iowa (KCAU) – Siouxland is going to experience very muggy weather along with the chance for some strong to severe storms possible in portions of the area throughout this weekend.
Temperatures have been on the comfortable side in the 80s, but this weekend temperatures are looking to be in the mid-90s. Humidity is also going to return to the area, which means the heat index values, or “feels like” temperatures, are looking to be in the upper-90s and low 100s.
With temperatures on the rise and humidity returning to the area, Siouxland is also looking at some thunderstorm chances between Saturday and Sunday, some of which could be strong to severe.
Severe thunderstorms need four main “ingredients”:
- Shear: Wind speeds increasing with height.
- Lift: Some sort of boundary that creates air parcels to rise.
- Typically caused by warm and cold fronts, mountain ranges, and other topographical features.
- Instability: Air parcels are warmer than their surrounding area, makes the atmosphere unstable, which ultimately creates thunderstorm production to get the atmosphere back in balance (stable).
- Moisture: The amount of water vapor in the atmosphere. This is looked at by both relative humidity and dew points.
On Saturday, portions of Siouxland could see some early morning showers and thunderstorms. The morning storms (or convection) will lead to more humid conditions for the afternoon hours. Those humid conditions mixed with the late morning and afternoon sunshine will create a fairly unstable environment for the evening and overnight hours. This is a very typical storm set-up for strong to severe storms.
Portions of eastern Siouxland (mainly east of I-29) are currently sitting under a slight risk while portions of western Siouxland (mainly west of I-29) are sitting under a marginal risk for severe weather. The severe risks were issued by the Storm Prediction Center and are updated daily.
This means that the storms Saturday night into Sunday could be strong to severe. The main hazards associated with these possible strong to severe storms include damaging wind gusts up to 60 mph or higher and large hail around an inch in diameter or larger. We could also see some localized heavy rainfall at times where the stronger/ severe storms are located. The localized heavy rainfall could also lead to other hazards like flooding/ flash flooding.
The strong to severe storms that are possible on Saturday will be moving in during the evening hours on Saturday and will linger into the overnight hours/ early Sunday morning hours.
The few storm chances we could see throughout Sunday morning and Sunday night are looking to be more general thunderstorm-like; however, portions of Siouxland are sitting under a marginal risk for severe weather due to the amount of humidity and heating we will see return Sunday afternoon.