Environment Canada has issued a Snow Squall Watch for the Stratford area.
The weather agency says persistent snow squalls are expected to develop Wednesday and continue into Thursday morning.
Under the snow squall bands, visibilities will be significantly reduced due to the heavy snow combined with blowing snow, and snow will quickly accumulate.
Five to 10 centimetres is expected by Wednesday evening.
Wednesday night into Thursday morning the snow squalls may intensify locally and up to 15 centimetres is possible in the heaviest snow squalls.
Snow squalls cause weather conditions to vary considerably; changes from clear skies to heavy snow within just a few kilometres are common.
Travel may be hazardous due to sudden changes in the weather and officials say visibility may be suddenly reduced at times in heavy snow.
