May 8 Severe Weather Threat

Once again a weak low pressure system is centered just southeast of Sioux City, with a warm front extending eastward parallel to Highways 20 and 30. This warm front and low pressure system already has a few clusters of isolated thunderstorms just north of the boundary and near the center of low pressure. These storms should continue to evolve and potentially become better defined through the afternoon hours. Additional development is expected through the afternoon to the south of the warm front in the warm sector where temperatures and into the 70s and dew points in the 50s. Areas of surface based instability have developed and should support surface based supercells within the next few hours. Supercells do appear to be the best threat for areas along and south of the warm front; current meso-analysis indicates that an enhanced area of shear and instability exists for areas along and just north of I-80 in western Iowa.

Storms currently developing near the surface low along the Missouri River should continue to move eastward into the area of enhanced shear/instability. If these storms are able to stay discrete over the next few hours, severe thunderstorms capable of large hail and an isolated tornado or two may also be possible.

Although I will not be chasing today, my virtual target area would be along I-80 in western Iowa; likely near Guthrie Center. Additional updates during the afternoon are likely...