Severe thunderstorms are possible Thursday across the Northern Plains. Strong to marginally severe thunderstorms are possible for the Intermountain West and Northern Rockies. Strong thunderstorms are possible across the Southeast.
Northern Plains: A series of upper level disturbances combined with a surface cold front moving eastward across the northern U.S. will generate thunderstorms across the region beginning Thursday afternoon and continuing into the overnight hours. Conditions will be favorable for severe thunderstorms, including supercells. Damaging winds, large hail, and a few tornadoes will be possible. Thunderstorms will likely evolve into a large complex by the late evening hours as they move eastward and may eventually lead to some areas of locally heavy rainfall as well.
Intermountain West & Northern Rockies: Further west, a stalling frontal boundary will be a focus for continued thunderstorm development across portions of the western U.S. on Thursday. Conditions will remain favorable for additional strong to marginally severe thunderstorms once again.
Southeast: An unstable air mass combined with deep moisture is expected to be in place across portions of the Southeast on Thursday, along and south of a weakening frontal boundary. This will lead to the development of afternoon/evening thunderstorms, with a few strong storms containing gusty winds and hail possible.