May 11, 2004

Manitoba Water Stewardship reports that flooding is unlikely across southern Manitoba as a result of the present storm system. This vigorous storm, originating in the Utah-Colorado area, is producing heavy snow and rain across southern areas of the province.

The storm had produced up to 25 cm of snow in some areas as of noon today and is expected to continue tomorrow. Precipitation in most areas will be mainly in the form of snow, which will easily soak into unfrozen soils.

There is some concern about localized flooding in areas closer to the U.S. and Ontario boundaries where thunderstorms are possible.

Southeast Manitoba:

• Localized flooding problems may develop in areas near the Ontario boundary from the Winnipeg River south to the U.S. boundary, but only if thunderstorms with heavy rain develop.

• This area of concern includes the Whitemouth River, Sprague Creek, Pine Creek and the Whiteshell area.

• Eastern tributaries of the Red River may experience some rises as most of these streams still have high subsoil moisture levels which will reduce soil absorption and increase run-off.

• Only minor rises are expected on the Assiniboine River, Pembina River, western tributaries of the Red River and points north of the Trans-Canada Highway.

Major Rivers:

• Flooding on the Winnipeg River cannot be ruled out as up to 100 mm of rain is predicted in Northwestern Ontario. Flooding on the Manitoba portion of the Winnipeg River would take nearly two weeks to develop.

• Only minor rises are expected on major rivers such as the Red River or the Assiniboine River.

The Hydrologic Forecast Centre will watch the weather and river conditions. A flash flood watch may be issued later today or tomorrow if it appears that rainfall amounts in southern Manitoba will exceed 60 mm over large areas.

Snowfall has been heavy in areas south of a line through Clear Lake and Arborg to the U.S. boundary. However the snow has tapered off north of the Trans-Canada Highway and little further precipitation is expected in these more northerly areas. Localized heavy rain and thunderstorms have been reported in the Killarney area and are expected to redevelop further east later today and tomorrow according to Environment Canada. Precipitation is expected to continue through most of tomorrow with total amounts of 40 mm and localized amounts of 70 mm predicted in areas closer to the U.S. boundary.

-30-