Flood forecasters in our province are tracking another weather system this weekend which could raise river levels again.
Manitoba Transportation and Infrastructure's Hydrologic Forecast Centre is monitoring a potentially significant precipitation system that could bring 40 to 80 millimetres (mm) of precipitation over the upcoming weekend. The precipitation system may fall as a rain and snow mix bringing up to 30 centimetres (cm) of snow and the remainder (up to 50 mm) as rain in the central and southern Manitoba basins.
Weather models do not fully agree on the exact location, amount and timing of the precipitation system. However, confidence is high that most central and southern Manitoba basins, including the United States portions of the Red, Souris, Pembina and Roseau river basins, could receive 40 to 50 mm of precipitation with localized areas receiving up to 80 mm by April 24.
Daily average temperatures are forecast to remain above zero until early next week for most parts of southern and central Manitoba.
These forecast temperatures along with forecast precipitation will create runoff in the coming days and levels will start rising on most southern and central basins. Overland flooding could occur in areas where the highest-intensity rainfall occurs. Peak flows on the Red and Assiniboine rivers and tributaries are not expected to arrive until late April to early May.
Fisaha Unduche is Executive Director, Hydrologic Forecasting and Water Management with Manitoba Transportation and Infrastructure. He says if the precipitation falls as is being forecast, it will make this the second wettest April for the Red River Valley since 1950, exceeded only by April, 1986.
"These forecasted temperatures along with the forecasted precipitation event could create snow melt and some surface runoff and because of that we might start to see overland flooding occurring in some portions of the southern Manitoba basins, depending on how intense the rain comes," he says. "The most likely areas that could get overland flooding are areas in southwest part of Manitoba based on today's forecast."
The Red River is expected to crest between April 30th and May 7th. There is a moderate to major flood risk for the Red River, with a moderate flood risk for eastern regions, including the Roseau and Rat rivers.
Since Tuesday, the Red River has gone down two inches at Emerson to 774.25 feet, two inches at Morris to 760.74 feet, two inches at Ste. Agathe to 753.64 feet and three inches at St. Adolphe to 750.62 feet. Since Tuesday, the Roseau River has gone up one inch at Gardenton to 964.29 feet, less than one inch at Stuartburn to 948.55 feet and dropped one inch at Dominion City (PR 200) to 771.88 feet. Meanwhile, since Tuesday, the Rat River at Otterburne has dropped less than an inch to 763.08 feet.