This video is looking up into thunderstorms forming over Black Hawk County, Iowa on Saturday afternoon, July 23, 2016. Numerous small cells were congealing into a thunderstorm complex on a very warm and humid afternoon. This is the beginning of what turned into a severe thunderstorm complex that moved eastward to the Dubuque, Iowa area into northern Illinois. Cumulus clouds grew into cumulus congestus and cumulonimbus during a 45 minute period. Only a few brief downpours occurred here but nearly continuous thunder was heard to the east and southeast. The National Weather Service issued numerous severe weather warnings from Waterloo east along and near Highway 20 through the Dubuque area.
The Weather Briefing Blog