Severe Weather Outbreak

The state of Iowa is looking at three straight days of potentially significant severe weather. Today, or more likely, tonight will see a large complex of storms move into southwestern Iowa with the potential for both large hail and significant damaging winds. Storms today should fire across central Nebraska and Kansas, congealing into a MCS during the evening hours as it nears the Iowa and Nebraska borders. The extreme southwestern counties in the state may have a chance at an isolated tornado is storms can stay discrete for a longer period of time. The main threat with these storms should be damaging winds and large hail, with the best threat over southwest Iowa. The remainder of the state may still see thunderstorms during the overnight hours, with the potential for severe storms throughout. More updates on this threat may be posted during the evening or early overnight as the system is able to become better defined.

Tomorrow (Thursday) will see the northwest half of the state under the potential for significant severe weather, including very large hail, damaging winds, and tornadoes. A warm front to the north of the state, across southern Minnesota, with low pressure system in eastern South Dakota. A dryline and cold front will also be positioned from extreme eastern South Dakota through eastern Nebraska and then into central Kansas, Oklahoma, and even Texas. Although storms may be ongoing in the morning hours across portions of SD/NE/MN/IA, they are expected to clear off by the afternoon hours. Given clearing skies, strong instability should be present across the entire warm sector (south of warm front and east of dryline/cold front). The combination of strong instability and lift with associated fronts should allow storm development during the afternoon hours, with other storms developing further south along the dryline being more discrete due to a strong cap.

The storms expected across Iowa are likely to be supercellular, with very large hail and tornadoes being the main threats given strong shear at both low and mid-levels. Eventually the storms may congeal into another complex of storms, however this is not likely until they reach the eastern half of the state. Initial storms are being said to have the potential of long-lived, strong tornadoes. Thus, would definitely keep an eye and ear to the weather for tomorrow across parts of Iowa and adjacent areas.

Just a brief mention for Friday, as mainly a cold front passage over eastern Iowa will likely be capable of producing severe weather during the afternoon and evening hours. Although all modes of severe weather seem likely, the best threat will probably be large hail and especially damaging winds. More on this threat will be available as it nears...