DES MOINES, Iowa - A hot and humid day is underway in Central Iowa. The afternoon will continue to be muggy with lots of sun and strong winds from the south at 15 to 20 mph. However, the stage is being set for strong to severe storms late tonight across Iowa.
A Severe Thunderstorm Watch has been issued for Calhoun, Carroll, Humboldt, Kossuth, Pocahontas, Greene, Audubon, Hamilton, Wright and Webster County until 11 p.m. Monday.
Parts of Central Iowa are included in a slight risk area, as well as an enhanced risk area. The enhanced risk area includes Kossuth County through Fort Dodge and Carroll, extending towards Atlantic and Creston, in the west central Iowa. An enhanced risk area means numerous severe storms are possible. They will be more persistent and widespread. A few may be intense. Several reports of wind damage are expected and there could be some damaging hail of 1 to 2” in diameter.
This evening, thunderstorms will begin to develop in southeastern South Dakota, Eastern Nebraska and Northwestern Iowa. This is where an incoming cold front will intersect with the remnant boundaries of morning convection in that part of our region. There is some severe risk at that time, but the window is very narrow. A few super cell storms may develop and there may be a risk of tornados primarily in the eastern Dakotas and southwest Minnesota initially.
These initial storm cells will begin to merge and grow upscale moving forward in a line toward Central Minnesota and Central Iowa. The risk of damaging winds will begin to increase for Western Iowa by 9 p.m. and in Central Iowa by 11 p.m. A strong low-level jet from the south-southwest will continue to fuel the storms and keep their intensity up.
The storms will bring strong winds as they move through Central Iowa between 11 p.m. and 1 a.m. Some hail is also possible. There will also be heavy rain. Most locations could see up to ¾ of an inch and a few locally higher totals nearing 2” are possible.
The storms will exit the state early Tuesday morning and Tuesday will begin dry and quiet in Central Iowa.