The increase in heavy precipitation events is associated with an increase in water vapor, and the latter has been attributed to human - induced warming. (climatecommunication.org)
It has been noted that an increase (or decrease) in heavy precipitation events may not necessarily translate into annual peak (or low) river levels. (ipcc.ch)
Overall, it is likely that there has been a 2 to 4 % increase in the number of heavy precipitation events when averaged across the mid - and high latitudes. (ipcc.ch)