Strong to severe thunderstorms are possible Tuesday across the Upper Midwest to Central Plains. Strong thunderstorms are possible for portions of the Northeast. Heavy rain is likely across the Upper Midwest and Montana.

Upper Midwest to Central Plains: A cold front will continue moving eastward on Tuesday. Increasing low level moisture ahead of the front will help fuel instability across the region. Thunderstorms, potentially oriented in a strong line, will likely be ongoing early in the morning. These storms should weaken some during the morning hours but may intensify again by the afternoon and evening as they push eastward. Strong to severe thunderstorms containing gusty winds and hail will be possible.

Northeast: An upper level disturbance is forecast to move southward out of Quebec on Tuesday. By the afternoon hours, instability should be sufficient to allow for the development of thunderstorms. Strong thunderstorms containing gusty winds and hail will be possible before weakening near or after sunset.

Upper Midwest:In addition to the severe threat mentioned above, there will be a heavy rain threat across portions of Iowa, southeast Minnesota, northwest Illinois, and Wisconsin, especially during the evening and overnight hours as thunderstorm coverage increases ahead of an approaching cold front. Rainfall amounts of 1-3 inches, isolated 4+ inches, will be possible and could lead to an increased flooding threat across the region.

Montana:A surface low pressure area will continue tracking to the east-northeast on Tuesday, with showers and thunderstorms on the backside of the low spreading into northeast Montana. There will be a threat of heavy rainfall in this region with 1-3 inches, isolated 5+ inches, possible.