Highlights:

• A Special Weather Statement has been issued by Environment Canada due to significant rain in the forecast.
• Forecasts of 30-50 mm of rain, Wednesday into Thursday, with higher amounts possible from thunderstorms
• Areas of ponding, standing water and localized flooding expected around the region.
• Watercourses expected to rise and some could spill their banks into adjacent low-lying areas.
• Thames River will likely rise and flood the low-lying river flats from Delaware down to Chatham.
• In Chatham, flooding of the sidewalk along the river in the downtown is expected.

Message:

A Special Weather Statement has been issued by Environment Canada due to significant rain in the forecast. Another low-pressure system is expected to move into southwestern Ontario tomorrow (Wednesday) morning bringing rain, heavy at times, and thunderstorms. Currently, the Special Weather Statement is calling for 30 to 50 mm of rain for Wednesday and early Thursday, with locally higher amounts possible due to thunderstorms. It also notes that Rainfall Warnings may be required for some areas as the event draws nearer. Some weather forecasts are suggesting even higher rainfall amounts. The possible thunderstorm activity creates uncertainty in the forecasted amounts of rain. Forecasts for the weekend are calling for additional rain late Friday and Saturday. The ground is still wet from the rains last weekend and has little ability to absorb more water.

Even the lower amounts of rain in the forecasts would cause ponding, standing water and localized flooding. Smaller watercourses that drain into the Thames River, or to the lakes, should be expected to rise and some could spill their banks into adjacent low-lying areas. The LTVCA expects to have to operate the McGregor Creek Diversion Channel, which is designed to protect the south end of the city of Chatham from flooding on McGregor Creek. With additional rain in the forecasts for the weekend, water levels could rise again, and water levels should be expected to remain high into early next week.

The Thames River will also rise in response to the rain. The river is still running higher than usual from the rain last weekend. With the additional rain predicted for tomorrow, the river will rise even further. In Chatham, the river is expected to rise and flood the sidewalk along the river in the downtown. Based on the forecasts, it is also likely that the river will rise and flood of the low-lying river flats adjacent to the river from Delaware down to Chatham. Once the rain has fallen, if required, this message may be updated with additional details on any flooding that may occur from the Thames River. Water levels on the river should be expected to remain high into next week as water from the upper Thames River watershed works its way downstream.

People should take extra caution and avoid the river, ditches, and streams. The combination of slippery banks and fast-moving cold water can be dangerous. Standing water can also present its own unseen hazards. Children and pets and livestock should be kept away from the water.

Officials will continue to monitor the situation and update this advisory if necessary.

This message will be in effect until April 8th, 2025.

Contact: Jason Wintermute ([email protected])