Severe thunderstorm and flooding risk for Waterloo region

Submerged walking path at Schneider Park along the Grand River in Kitchener. (Dan Lauckner/CTV News Kitchener)

Environment Canada is warning that Wednesday may be a messy one.

A low pressure system, moving through the northern United States, may pick up power as it passes over the Great Lakes, bringing a risk of severe thunderstorms matched with heavy rainfall and strong winds.

Satellite radar shows rain beginning early Wednesday morning.

Central and southern Ontario then see an increased risk of isolated yet severe thunderstorms developing just after sunrise. The risk of severe thunderstorms continues throughout day.

Rainfall amounts of 20 to 40 millimetres are possible within a 24 hour period.

With the recent snow melt, many waterways are already at a high level and the risk of flooding is expected to increase.

If severe thunderstorms develop, gusty winds upwards of 70-90 km/h are possible. Loose objects may be easily tossed by the wind and power outages are possible. Hail of two centimetres in diameter is also possible.

The first noticeable humidex of the year may arrive Wednesday as well.

Temperatures will be well above normal with a daytime high of 20 degrees Celsius is expected, and with the humidex, will feel more like 25 degrees Celsius outside.

A high humidex reading can encourage severe thunderstorms.

The public is being reminded that thunderstorms, though beautiful, can be very dangerous.

As the saying goes, “when thunder roars, head indoors.”