04/13/2026
Thunderstorms are expected to develop across the region this afternoon into this evening. These storms will be capable of all modes of severe weather, including large to very large hail, damaging wind gusts, and a few tornadoes. Repeating storm activity across the same areas may also lead to a localized flash flooding threat, particularly across central Wisconsin. The severe risk will continue into the overnight as storms exit to the east.
TMING: Storms develop this afternoon either across western WI or portions of MN/IA. These storms will then tend to move east/northeastward through the evening and into the overnight. The greatest severe weather risk will be between 4-10pm, though any storm that occurs today/tonight may be strong to severe.
HAZARDS: Initial storm development will likely pose a main threat of large to very large hail (potentially up to 3” in diameter). However, any storms that can remain more discreate along/south of the warm front will quickly see an increase in the tornado risk late this afternoon through the evening hours. The greatest chance for a few tornadoes will be located across west-central WI. Storms are expected to eventually cluster in one or more bowing segments and/or lines, with the primary severe risk transitioning to damaging wind gusts of 50-65 mph. An embedded tornado or two may still occur. Heavy rainfall and frequent lightning are expected with all storms today. The greatest chance of any localized flash flooding will be across central WI.
CONFIDENCE: Confidence is now high in thunderstorm development this afternoon/evening. Confidence in the evolution of severe hazards is also on the higher side, though there remains some uncertainty regarding how expansive the overall tornado risk will be (conditional tornado risk).
FORECAST DISCUSSION: Going to keep this very brief as I am running behind… Forecast models continue to suggest a considerable severe weather episode for Wisconsin this afternoon into tonight. A slight shift to the south has occurred overnight in the overall severe risk, with the greatest probabilities now located firmly across central WI. The tornado risk remains conditional on whether storms can remain more discrete into the evening, specifically any storms in the open warm sector or latching onto the warm front. The NWS has issued a flood watch across portions of central WI to highlight the flash flooding risk, as some training/repeating of storm activity is likely.
Please have multiple ways to receive severe weather alerts today and take those alerts seriously! I will have infrequent updates throughout the day, but I should absolutely not be your primary source for weather alerts.
