Environment Canada says conditions are favourable for the development of dangerous thunderstorms.
A severe thunderstorm watch has been issued across Renfrew County and parts of the Ottawa Valley.
The main hazards include wind gusts up to 90-kilometers an hour, nickle size hail and heavy downpours.
Environment Canada says the thunderstorms could hit this afternoon and into the evening ahead of a cold front tracking through the area.
(written by: Rudy Kadlec)