This morning, a batch of showers and thunderstorms are giving parts of Iowa a preview of what’s to come later this afternoon. A strong cold front will push through the state. Behind this front is cooler and drier air. This interaction is expected to serve as the focal point for explosive thunderstorm development later today.
As you can see in the graphic to the left, much of the state falls under a slight risk for severe weather. A cap is expected to prevent storms from developing for much of the day. This morning, some showers and thunderstorms are rolling across portions of eastern Iowa. At this time I don’t believe these storms pose much of a problem for another round later today as there is plenty of time and energy to recharge the atmosphere for the main event.
One the cap erodes sometime after 3pm, thunderstorms should quickly develop and turn severe. Current indications are that shear values over Iowa will primarily be unidirectional, keeping the tornado threat low. The primary threats are for large and and widespread strong, damaging winds. These storms will also pack a very wet punch. With so much moisture in the air, heavy rain in excess of 1-3” is possible in local areas, especially if some storms begin to stall out later tonight.
That’s what we’re expecting from this cold front. Eventually the boundary will stall out, perhaps somewhere over southern Iowa or northern Missouri. With the boundary lingering in the area, additional chances for severe weather exist for Thursday and Friday. We’ll have more on tomorrow’s threat later this afternoon but for now I just want to focus on today’s threat. We’ll have an update on what this threat means for Iowa later today and, if needed, we’ll launch our live coverage of the storms later today.