The Manitoba Hydrologic Forecast Centre has issued an Overland Flood Warning for all of Southern Manitoba ahead of a moisture-laden system which could drop substantial rainfall across the region beginning late Monday night through Tuesday night.
The warning will be in place until Wednesday, according to the Province.
New weather system could bring 25-150 mm of rain over the next 48h to all areas south of #MBHwy16 & #MBHwy1. Overland Flood Warning is issued in these areas as higher amounts of rain could create localized overland flooding. https://t.co/U74aBgoSix pic.twitter.com/mEtKk4ZsNZ— Manitoba Government (@MBGov) July 18, 2022
"An upper level low pressure system, which moved out of the Rockies earlier today, is moving across the southern Prairies over the next twenty-four hours, and will produce this potentially substantial rainfall event," explained CMOS Accredited Weathercaster Chris Sumner. "It's been very difficult for forecasters to pin down just how much rain there could be, for a number of reasons, including the likelihood of embedded thunderstorms leading to locally higher totals in areas which see them. How fast and how hard the rain comes down, and where, will play a major role in whether overland flooding develops."
Environment Canada is currently projecting rainfall totals of 20 to 30mm, possibly up to 50mm in thunderstorms, in most regions of Southwestern Manitoba, the Red River Valley and Southeastern regions.
"As this system moves in, it also may trigger severe thunderstorm activity late Monday night, into the overnight hours and early Tuesday morning," noted Sumner. "At this point, heavy rain, very strong winds and potentially hail would be the primary threats if storms develop."