The St. Clair Region Conservation Authority has issued a flood watch as 10 to 20 millimetres of rainfall is expected.
The conservation authority said a Colorado low will make its way to Ontario between Thursday evening and Friday morning.
The rainfall and above-freezing temperatures are expected to speed up the snowmelt process, and elevate water levels. As a result, there could be minor flooding in natural floodplain areas, parks, and fields.
"A snow survey conducted earlier this week on March 14th found the remaining snowpack to be heavy, with a snow-water equivalent (SWE) of 60 mm near Warwick and over 30 mm SWE near Strathroy," read a media release from the conservation authority. "Locations near Petrolia, Alvinston and Wallaceburg were found to have reduced snowpacks, however forested and shaded locations continue to hold more snow and therefore a higher SWE."
Conservation officials are reminding residents to avoid water courses and flooded areas due to safety concerns.
The flood watch will remain in effect until Sunday.
