After a hot and humid day Friday, relief will not come until a cold front moves through the state Saturday evening. As this cold front moves through the state, severe weather will be possible across the state. However, there remains some question to just how severe storms will be Saturday afternoon or even if they will even form.
This uncertainty exists because there remains many questions around how things will evolve tonight. This afternoon, severe storms are forming across the eastern Dakotas and western Minnesota. These storms appear to form into a MCS, and will push to the southeast this evening after midnight across northeast Iowa. This will increase cloud cover across the state this evening.
It does appear that storms will dissipate across northeast Iowa by sunrise Saturday. This would then allow the atmosphere to bounce back and become unstable by Saturday afternoon. The only issue that could arise is the atmosphere remains capped, and would hold down the storm potential.
The National Weather Service in Des Moines has quoted it the best. “We are left with an all or nothing forecast for thunderstorms Saturday afternoon and evening, likely boom or bust as we will either stay capped and see sunny skies or break the cap and have multiple severe thunderstorms.” They go on to say that they believe that “it seems more likely than not that the cap will break and thunderstorms will develop.”
Because of the rich atmospheric dynamics, it does appear likely that severe storms will develop along the cold front tomorrow afternoon. The best potential appears to be across northeast Iowa, north of interstate 80 and east of interstate 35. We will have multiple chase teams out tomorrow if things appear to materialize after looking over the morning data, and will be streaming live. Continue to check back here for all the very latest updates.