Good afternoon everyone! We currently (as of 4:05pm CDT) have a decaying Mesoscale Convective System (MCS) quickly progressing eastward across southeastern MN with some broken development occurring recently along its southern periphery in northern IA. A smaller complex of storms is following behind this MCS in southwestern MN. These storms will continue to push eastward through the remainder of the afternoon and evening hours.
Given steep lapse rates and modest instability in southern MN/northern IA, some of these storms in association with this complex may become strong with hail and damaging winds not off the table. A few warnings have been issued along this complex over the last couple of hours, so the threat remains. An additional complex of storms later tonight will also bring the threat for gusty winds and some hail in similar locations.
Multiple rounds of storms are expected in the region over the coming days, with the southern third of MN into northern IA the prime spot for heavy rains and localized flash flooding.
Here’s a brief synopsis of what to expect with the additional storms expected to fire into tonight: These storms will ignite in a similar location to the storms that are tracking through the area currently. This round of heavy storms is expected to develop ~10pm CDT first in southwestern MN before additional development along its eastern periphery occurs further east across the southern third of MN, progressing southeastward into northern IA overnight and a good majority of eastern/southern IA Tuesday morning.
Simulated radar through 7am CDT Tuesday: The complex of showers and storms across southern MN into far northern IA will progress eastward through the evening hours, mostly exiting the area by 10pm CDT. This is also about the time previously discussed when new development over the southern third of MN is to take place, diving into IA overnight into Tuesday morning. As noted, some portions of this complex of storms may become strong with damaging winds and large hail the main threats. A few pop-up showers and storms may develop to the south of these complexes over IA before these main features progress through.
What can be described as our third wave of showers and storms across the region will impact western MN into IA starting mid Tuesday morning, especially over far southwestern MN into western IA where better forcing will remain. These storms will also follow in a similar direction to the previous waves, along the northern periphery of an upper-level ridge further south. While there is energy in west-central MN during this time, coverage of showers and perhaps a couple storms will be limited.
Simulated radar from 7am CDT Tuesday through 7pm CDT Tuesday: The wave of strong storms overnight tonight will continues its dive southeastward across IA through the morning hours with development possible along its western periphery in western IA. These storms will either slowly fade or exit the region with our next pulse of energy providing heavy shower and storm risks to southwestern MN and western IA from mid-morning Tuesday through the end of this loop. This strong complex will likely fade through the late afternoon and evening hours across IA. Spotty hail and damaging winds are also possible with this feature.
More energy will funnel into the southern third of MN into northern IA during the evening and overnight hours Tuesday into Wednesday. This wave may prove to be more intense with heavy doses of rain and some strong storms in these areas. Some energy further north could bring shower and storm risks to central MN.
Simulated radar from 7pm CDT Tuesday through 7am CDT Wednesday: Widespread, heavy showers and storms will ignite across the southern third of MN into northern IA during the evening and overnight hours, slowly progressing southward into central IA by 7am CDT Wednesday. This will likely be a very heavy complex of storms and flash flooding will be on the table. Scattered showers and storms are possible further north in central MN during the overnight hours.
Here’s a look at total rainfall through 7am CDT Wednesday: Very heavy rains are likely from multiple rounds of storms over the southern third of MN into a large portion of IA. Localized flash flooding is possible.
If you have any questions do not hesitate to reach out! Have a great evening!