Our cousins in Winnipeg are dealing with the celestial overflow that triggered flash flooding. The Weather Network attributed it to the, by now standard, slow-moving rainstorm that hit the city and lingered long enough to deliver more than 75 mm. or 3" of rain in about 90-minutes.
It's been a common story this summer. Heavy rainstorms that used to move steadily eastward, spreading rainfall across wide areas, now loiter. When these storms park over one area they deliver amounts of rainfall that quickly overwhelm first storm sewers and then other infrastructure such as roads.
In the States, flash flooding has hit Chicago and parts of Arizona.