GRCA Weather Alert:Threats Of Urban Flooding, Dangerous Conditions
Watershed Conditions Could Turn To Flooding
A weather system will move into the watershed on Thursday bringing warmer temperatures and rain. The current weather forecast indicates the warming trend associated with this system will be relatively short lived. Air temperatures are expected to rise above freezing by noon today; reaching approximately 7 degrees by early Friday morning, before a rapid cooling trend returns late Friday morning. Much colder temperatures are forecast through the weekend and into next week. Weather forecasts are anticipating approximately 30 mm of rain will accompany this event.
The limited duration of the forecast warming trend is not expected to cause significant melting of the snow pack. Much of the rainfall accompanying this event is expected to be absorbed by snow already on the ground. No major runoff is anticipated into the larger rivers in the watershed and ice in the larger rivers is expected to remain intact.
In urban areas, the potential for street flooding exists where catch basins are covered with snow and ice. Runoff is expected from urban areas into urban streams. Fallen tree debris along urban watercourses from the December ice storm poses a risk for debris jams. Municipal public works staff should keep a close watch along urban water course due to this potential risk.
Banks adjacent to rivers and creeks are very slippery at this time and when combined with forecast weather conditions, pose a serious hazard. Parents are encouraged to keep their children and pets away from all watercourses and off frozen water bodies which may be weakened as a result of the warming trend.