A low pressure system will track through the Great Lakes region Thursday evening, bringing rainfall of 10-15 mm to Southern Ontario. The system also has the potential for embedded thunderstorms which may result in localized areas receiving additional rainfall amounts of up to 25 mm.
A survey of the snow pack this morning showed that the remaining snow cover is largely confined to woodlots. Soils remain fairly saturated from last week’s rain and snowmelt.
Based on the current weather forecast, river levels are expected to reach or slightly exceed bankfull conditions with flooding limited to traditional flood prone areas. Municipal staff have been asked to monitor local problem areas and be prepared for the closures of low lying roads.
If thunderstorms do not materialize, river flows are expected to peak early Friday evening in headwater areas. Flows in larger watercourses are expected to remain high through early next week. It should be noted that if thunderstorms do occur more significant flooding can be expected, especially in flood prone areas. The thunderstorm potential is currently forecasted for the period from 2:00 am to 9:00 am on Saturday morning (March 21, 2020). River levels will respond quickly to any thunderstorm activity.
Residents are reminded to stay away from rivers, ditches, and streams. Flows will be very fast and very cold over the next several days.
Maitland Conservation staff will continue to carefully monitor the forecast and an update on watershed conditions will be provided if warranted. This message will remain in effect until 10:00 a.m. on Monday March 23, 2020.
Jeff Winzenried, Water Resources Technician
Jayne Thompson, Communications Coordinator
519-335-3557 ext. 226 Cell: 519-357-6670
Types of Flood Messages:
Watershed Conditions Statement – Water Safety – General watershed conditions are being assessed for high runoff potential that could lead to flooding, and to remind the public of general river safety issues.
Watershed Conditions Statement – Flood Outlook – Early notice of the potential for flooding based on weather forecasts calling for heavy rain, snow melt, high wind or other conditions that could lead to high runoff, cause ice jams, lakeshore flooding or erosion.
Flood Watch – Flooding is possible in specific watercourses or municipalities. Municipalities, emergency services and individual landowners in flood-prone areas should prepare.
Flood Warning – Flooding is imminent or already occurring in specific watercourses or municipalities. Municipalities and individuals should take action to deal with flood conditions. This may include road closures and evacuations.