Regional Impacts
Today
NB/NS/PEI: Risk of thundershowers, possibly near severe into this evening with gusty winds and locally heavy downpours.
NFLD: Risk of thundershowers this afternoon and evening with locally heavy downpours.
LAB: None.
Tonight
NFLD: Chance of an isolated thundershower overnight and early in the morning with locally heavy downpours.
NS/NB/PEI/LAB: None.
Tomorrow
NB/NS/PEI/NFLD/LAB: None.
Convective Discussion
A shortwave is moving into the Gaspe Peninsula this morning and will be the main trigger for convection today across the Maritimes, Gulf of St. Lawrence, and Newfoundland. Scattered showers across northern New Brunswick will continue this afternoon across PEI, reaching northern Nova Scotia by the evening. MLCAPE values out ahead of the system are expected to rise to 500 to 750 J/kg, with the highest SBCAPE potentially reaching 1200 J/kg expected over southeastern NB, PEI, and north and eastern NS. Although there are fairly weak lapse rates with temperatures warmer at 500 mb, there is still appreciable precipitable water in the mid 30s, drier air between 700 and 500 mb, and effective shear of 40 to 50kt. There is a risk of thunderstorms reaching severe limits and a non zero risk of an isolated supercell this afternoon mainly over the aforementioned areas. Surface-based thundershowers may also develop over central Newfoundland this afternoon.
A risk of thundershowers exists overnight with the shortwave as it tracks east of Cape Breton towards eastern Newfoundland by the morning.
For tomorrow, the shortwave is expected to weaken as it moves east of Newfoundland but there may still be a risk of a thundershower in the early afternoon. A ridge of high pressure will set up over the region on Sunday, leading to a quiet couple of days to begin next week.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
