Severe Weather Threat

Another storm system moving into the plains will put the state under another risk of severe weather tomorrow, June 2. As mid-level winds become westerly in nature, indicating more zonal flow; low-level winds will be backed to the southeast and even east during the afternoon hours. This shift in winds with height will allow for sufficient shear values throughout portions of NE/KS/IA/MO for supercells. Low-level shear becoming enhanced with the easterly surface winds over portions of Nebraska, Iowa, and potentially other areas, for a tornado threat during the evening hours.

At the surface, a warm front will likely be positioned across extreme southern South Dakota and Minnesota, and also over portions of central/western Nebraska. To the south of this feature, expect mainly clear skies for the afternoon hours will provide sufficient instability for severe weather as well. Thunderstorms are likely to initiated over Nebraska and South Dakota during the late afternoon hours, moving into areas of Iowa and Missouri during the evening and overnight. The initial storms are likely be remain fairly discrete, with the potential for all modes of severe weather. With time the storms should congeal into a potentially significant MCS capable of damaging winds and hail, with a brief tornado still remaining possible.

More details on the position of the warm front, how well the area south of the front can clear, and what the trigger for convection to begin will become clear during the day tomorrow. It is expected that the SPC will upgrade the risk area to a moderate, for at least the area that is forecasted to receive the significant MCS during the evening and early nighttime hours. Another update can be expected late tonight or early tomorrow with more details on the locals expecting the more significant severe weather.