On the question of "Are Storms Bigger and More Frequent Due To Climate Change?" - the CBC Ombudsman has recently consulted Environment and Climate Change Canada (ECCC) in response to complaints on reporting inaccuracy and ECCC indicated: “For Canada as a whole, observational evidence of changes in extreme precipitation is lacking.”
ECCC has confirmed the observation that extreme precipitation has not changed in across Canada in its recent Canada's Changing Climate Report which states: "For Canada as a whole, there is a lack of observational evidence of changes in daily and short-duration extreme precipitation.", and "There do not appear to be detectable trends in short-duration extreme precipitation trends in Canada as a whole based on available stations data."
CBC has corrected their coverage on this ECCC report in this article saying "Correction - An earlier version of this story said that more intense rainfall contributes to increased urban flooding. In fact, while the report states that precipitation is higher overall, it did not find that episodes of short-duration extreme rainfall have increased or establish a connection between these and increased or exacerbated flooding."
Our review of the most current Engineering Climate Datasets (Version 3.0) shows that in southern Ontario, design rainfall intensities continue to decrease since 1990 - see review of IDF trends long term climate stations. Overall, frequent storm intensities (i.e., 2 Year storms) and infrequent storm intensities (i.e., 100 Year storms) have decreased in intensity - frequent storms, those we have observed the most and have the most confidence in trends, have decreased the most.