SIOUX CITY, Iowa (KCAU) – It’s been a hot run in Siouxland with plenty of days in the 90s and very little relief, but some relief is on the way and it’s looking to stick around for a few days.
Siouxland is projected to experience a cold front tonight (July 13). A cold front is the leading edge of a cooler air mass that will replace the warmer weather at the surface. Cold fronts are typically located within a low-pressure system.
Before the cold front moves through, Siouxland will experience a hot day with mostly sunny skies, a light breeze, and temperatures gradually rising to a high around 92 degrees by the afternoon hours.
The good news is, cold fronts typically bring cooler weather to the area. Siouxland is looking at cooler weather returning Tuesday and lasting through Thursday. Temperatures will drop into the low 80s by Tuesday following the front passing through and will gradually rise back to the low 90s by Friday. The passage of this cold front will also lead to slightly less humidity in the area, meaning it will feel less sticky and humid between Tuesday and Thursday of this week. The humidity will still be present, just not as strong.
The cold front will start making its way into the area with some cloud coverage moving in ahead of the front. Clouds will start taking over around 9 p.m. The clouds will be moving in before the front arrives in Siouxland.
As the front arrives, it will be coming in from the west, which means western Siouxland will see scattered showers and thunderstorms before central Siouxland and eastern Siouxland.
The front will move into central Siouxland, which includes Sioux City, and areas along the I-29 corridor between 11 p.m. and 12 a.m. tonight.
When a cold front moves through, there is typically a line of thunderstorms and showers associated with it. These showers and thunderstorms will be moving into western Siouxland between 10 p.m. and 11 p.m.
Most of the storms are looking to stay in western Siouxland (west of I-29), with the chance for a few to reach the Sioux City area and areas along the I-29 corridor.
Not only are we looking at the chance for some scattered showers and thunderstorms later tonight, but there is also a chance for some of those thunderstorms to be strong to severe. A cold front acts as a form of lift, which is an ingredient for thunderstorm production (severe or non-severe). Lift is caused by air being forced to rise. For example, this is very similar to holding a ball underwater in a pool and letting it go. After letting the ball go, it floats right to the top of the water. In the sense of thunderstorms, the basketball would be the air, and the top of the water would be the top of the atmosphere.
Siouxland is located within a slight risk for severe weather. This means portions of the area could experience organized, but not widespread strong to severe storms.
The main threats of severe weather that could affect Sioxuland tonight include damaging winds up to 60 mph or higher and large hail possible up to the size of a quarter or higher. The risk for tornadoes is very minimal in this severe weather potential.
Not only is this cold front going to bring some more pleasant temperatures to the area, but portions of Siouxland will also see some more much-needed precipitation. As the front passes, Siouxland will see scattered showers and thunderstorms not only tonight but also on and off throughout tomorrow. Rainfall totals will range from around a tenth of an inch to a half an inch.