Message: Possible thunderstorms may cause flash flooding and pooling on roads
Thunderstorm activity this afternoon brought varying amounts of rainfall to the watershed, with approximately 80 mm in Sarnia and 55 mm in Warwick.
Environment and Climate Change Canada is forecasting the potential for further thunderstorm activity overnight into mid-day tomorrow, which could bring an additional 30 to 50 mm of rain with a peak rainfall intensity of up to 50 mm/hr. High amounts of rainfall in a short period of time can lead to increased runoff and flash flooding, particularly in urban areas. Local rainfall amounts could be higher due to the isolated nature of thunderstorms.
Water levels and flows are anticipated to increase and may elevate into natural floodplain areas should the watershed receive the upper end of the rainfall amounts. Low-lying areas and roads prone to flooding may become impacted, and ponding may occur in saturated and/or slow-to-drain soils.
Individuals are reminded to avoid watercourses and flooded areas due to dangerous conditions, slippery banks and swift moving water. Children and pets should be kept away from the water.
The Conservation Authority continues to monitor watershed conditions and will issue advisories to municipalities and media should flood issues arise. Municipal emergency response staff and road superintendents should monitor local conditions closely.
This message will remain in effect until 4 p.m. on July 17th, 2025, unless otherwise updated.
