Flash flood warnings strike north-east US amid wildfire smoke from Canada

Poor air quality from wildfires continues to plague New York City as several neighborhoods hit by thunderstorms

Saturday is delivering a double dose of dangerous weather across the north-eastern US, with smoky skies from Canadian wildfires giving way to severe thunderstorms that have already triggered a flash flood warning as torrential rain pounds parts of the region.

After a brief break on Friday, smoke from the wildfires moved back into New York City and surrounding communities on Saturday, sending air quality back into unhealthy levels.