Ping-pong ball-sized hail could be coming our way, according to Environment Canada. You may have heard some thunder rumbles roar through the region Monday evening. The national weather centre has issued yellow thunderstorm warnings for much of the region including Newmarket, Orillia, Washago and Muskoka. Meteorologists are tracking a storm that could bring strong winds and quarter- to Loonie- to ping-pong-ball-sized hail along with heavy rain. Environment Canada warns to take cover if a thunderstorm approaches and to protect yourself from flying debris when outside.