Convective Discussion.
A frontal wave currently over the lower St Lawrence will continue to move eastward today under a very strong upper level wind flow. The surface cold front has moved south of the St Lawrence river this morning and dry/stable air is now found west of it. The low cloud continue to dissipate over the Maritimes as the cold front approaches. Ahead of the front, the air mass remains marginally unstable and with the some limited daytime heating of the surface scattered thunderstorms will develop once a warm layer in the low to mid levels becomes eroded. Current radar indicates early development over the mountains of the Eastern Townships and Maine Highlands. These storms will propagate eastward as the front pushes through NB later in the day.
Regional Impacts.
Newfoundland&Labrador: Isolated non-severe thunderstorms.
Nova Scotia: Risk of a thunderstorm over central, northern and eastern regions.
New Brunswick: Scattered thunderstorms developing west of the region moving east. The main threat is very high wind gusts.
Prince Edward Island: Risk of thunderstorms late today.
Jean-Marc