UPDATE: Environment Canada ended the rainfall warning at 3:09 am.
Southwestern Ontario is about to get hit with some very wet weather.
Environment Canada has issued a rainfall warning for the entire region. Forecasters say London, Middlesex County, Elgin County, and Oxford County could see up to 30mm of rain by Wednesday morning.
The rain is expected to start falling Tuesday evening and will fall onto frozen ground that won't be able to absorb it. The weather agency says it's also possible the region may see scattered thunderstorms.
Echoing a warning issued Monday by the Upper Thames River Conservation Authority, forecasters warn some low lying areas may see flooding.