Regional Impacts
Today: Chance of organized thunderstorms over Cape Breton, Newfoundland and parts of Labrador today. Main hazard is very heavy downpours.
Tonight: Slight risk of an isolated thundershower over eastern Newfoundland.
Tomorrow: Some isolated thunderstorms possible over extreme southwestern Labrador.
Convective Discussion…
A low pressure system with a trailing cold front will be the driver for some organized thunderstorms today across Newfoundland and parts of southeastern Labrador. The cold front prompted severe thunderstorm watches and warnings across eastern Canada and the western Maritimes yesterday, with some organized convection persisting overnight and into this morning. The front will continue to move east today, with a strong stream of moisture being advected in over Newfoundland out ahead of it. The 12Z Stephenville sounding indicates 39 mm of precipitable water and 35 knots of bulk shear, however some warm air evident around 700 mb and weak MUCAPE may inhibit convection from becoming too organized especially given the amount of cloud cover ahead of the cold front. Given adequate clearing though, surface temperatures could rise into the high twenties which could be enough to overcome the warm air aloft and provide just enough energy for some marginally severe storms to develop. Given the high moisture but lack of steep lapse rates, the main threat with any thunderstorms today will be torrential rainfall in the 30 to 50 mm range.
The cold front will quickly move east across Newfoundland this evening, with some isolated thundershowers possible over eastern Newfoundland overnight.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
Forecaster: Copp