The weekend is here and with it comes two potentially dangerous rounds of severe weather across Iowa, Minnesota, Wisconsin and Illinois. Let’s begin with the first round set to impact parts of the state later today. The Storm Prediction Center has placed portions of northern Iowa under a moderate risk for severe weather today. You can see the area highlighted by this risk in the graphic to the right.
As a warm front sweeps from south to north across Iowa, showers and thunderstorms will develop late this afternoon and into the evening, producing a threat for severe weather. Although hail is the primary threat, all modes of severe weather are possible and it’s expected we could see several tornadoes in Iowa and Minnesota during the early evening hours. Storms may also reach far western Iowa late tonight as a dry line approaches from the west. All of this should produce an active day of severe weather across much of the area.
(Editor’s note: due to my wedding today I will be unable to provide updates on today’s storm. I sincerely apologize for the inconvenience and hope you understand how important it is for me to take my mind off of the weather today. Please stay safe today and I assure you we will resume full updates for Sunday’s potential outbreak tomorrow.)
Attention then quickly turns to Sunday when the atmosphere should become capped and rapidly destabilizes. With Iowa in the warm sector of the storm, temperatures should easily reach the 80’s in many areas with dew points reaching the 60 degree mark or higher. You can see in the graphic to the left a good portion of eastern Iowa is currently under a moderate risk for severe weather on Sunday. The Storm Prediction Center is already preparing to upgrade parts of this area to a high risk as the exact track of the storm becomes more clear.
Here’s how things should break down on Sunday. We anticipate storms will hold off until approximately 3pm. By that time, the cap should erode to a point that thunderstorms will develop along a secondary frontal boundary that could set up shop in northeast Iowa. Thunderstorm development will be rapid and intense. Supercells will take just minutes to form, capable of producing very strong winds, up to baseball size hail and of course tornadoes. In fact with the conditions in place tomorrow, the SPC is warning of the possibility of strong, violent, long-track tornadoes.
What is more troubling is with a dry line sweeping through the rest of the state, this threat of violent severe weather will continue for several hours into the evening. I cannot stress enough that this is a PARTICULARLY DANGEROUS SITUATION and it’s imperative that you keep up to date with the latest weather information on Sunday no matter what your plans are. In the graphic to the right you can see the overall probabilities for severe weather are extremely high for Sunday. Tomorrow morning we will get a better definition of the specific threats facing Iowa. We will of course bring that to you as soon as we can.
Our chase team plans to deploy to northern Iowa by early afternoon tomorrow. These will be difficult storms to track as movement is expected to be in the 45-55mph range. The largest of supercells however should slow to a point where they could be easier to track down, but either way it will be a very difficult day of chasing. We plan to launch live coverage right here tomorrow afternoon. We’ll do out best to provide live video from the field but if it doesn’t work please bear with us as we try to maintain the live chat. If things get hairy out there we’ll do our best to keep everything up and running. Above all, stay tuned and stay safe this weekend!