Downpours and thunderstorms will be moving from west to east across the state during the afternoon and evening.
Yesterday, the GTHA and other parts of southern Ontario were under a severe thunderstorm watch for most of the afternoon.
Those living in the impacted areas are urged to listen for updated forecasts and for possible Red Flag warnings.
National Grid reported almost 650 customers in Horicon, Chester, Schroon and North Hudson who lost power as of late afternoon, with restoration expected by early evening.
Starting in the early afternoon, some showers will start to pop up in the mountains and foothills; some thunderstorms could develop as well. Severe weather has been reported by spotters or indicated by radar.
After a storm lit up the sky Tuesday night and had lakeside residents bracing for damaging winds, another storm is unfortunately in the works. Move indoors immediately. Lightning is one of nature's leading killers.
Environment Canada has issued a severe thunderstorm watch for York and Durham regions.
Albertans can monitor weather on the Environment Canada website.
Eleven killed in Moscow storm
Hurricane of an unexpected severity has hit the Russian capital Moscow , with wind speed reaching 28 meters (92 fee) per second. Moscow's Domodedovo and Sheremetyevo airports have cancelled 13 flights and delayed 33 others due to the bad weather.