Highlights:

• Special Weather Statement in effect
• Various forecasts calling for 10 to 25 mm of rain Monday night through Tuesday night.
• Ponding and localized flooding is possible
• Higher rainfall amounts would cause local watercourses to rise and some could spill their banks.
• Higher rainfall amounts could also cause breakup and movement of ice on the Thames River.

Message:

There is currently a Special Weather Statement in effect from Environment and Climate Change Canada calling for a “significant rainfall” with the possibility of 15 to 25 mm of rain. Various other forecasts suggest a range of 10 to 25 mm. Rainfall in the region could begin as early as overnight tonight and last through Tuesday night, with most of the rain falling during the day Tuesday. Temperatures are currently above freezing and aren’t predicted to drop back below freezing until overnight on Tuesday. The amount of rain in the forecasts is very similar to what was seen last week. The frozen ground conditions and the amount of water stored in the snowpack are also very similar. Water levels on the Thames River have now peaked throughout the watershed, with water levels in Chatham peaking overnight last night. However, water levels on the river are dropping slowly.

The watershed could see a very similar event to what occurred last week given the current ground conditions and weather forecasts. (Although the additional freezing rain and snow after the rain is not predicted this time.) The warm temperatures and rain will melt out most of the remaining snow in the west of the lower Thames watershed. The higher rainfall amounts could do the same in the east of the lower Thames watershed. Given the frozen ground conditions, this amount of rain in the forecast will likely cause ponding, standing water and localized flooding in low lying areas and areas of poor drainage. Smaller local watercourses will rise and some could spill their banks. Many of these smaller local watercourses are still filled with snow and ice which could cause blockages and add to drainage issues. With the amount of rain in the forecasts, the LTVCA is prepared to have to operate the McGregor Creek Diversion Channel again.

Along the lower Thames River, water levels are still up from last week’s rain and are falling slowly due to the ice on the river. Depending on the amount of rain received and how much water runs off into the river, it is possible that water levels will rise up again and to levels higher than the peaks last week’s rain caused. Most of the ice cover on the Thames River remained intact after last week’s rainfall event. However, if this new rain causes water levels to rise up higher than previous peaks, it is possible that the river ice could break up and being moving. If the ice begins to break up, the river will need to be watched closely for the possibility of ice jams.

People should take extra caution and avoid the river, ditches, and streams. The combination of slippery banks, broken or unstable ice and fast moving cold water can be dangerous. The ice on the river should no longer be considered safe. 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 as necessary.

This message will be in effect until February 23rd, 2022.

Message Contact: Jason Wintermute ([email protected])