Regional Impacts
Nova Scotia.. Slight Risk of thunderstorms today giving heavy downpours and strong winds.
New Brunswick.. Slight Risk of thunderstorms today giving heavy downpours and strong winds. Risk of Severe thunderstorms late tomorrow.
PEI… Low risk of thunderstorms.
Newfoundland.. Slight Risk of thunderstorms today giving heavy downpours and strong winds.
Labrador.. Slight Risk of thunderstorms today giving heavy downpours and strong winds.
Convective Discussion
Our generally unsettled air mass will remain unstable today, with CAPE values exceeding 1000 J/kg across much of the Atlantic Provinces. Moderate shear could be a factor in the Maritimes, with a slight chance that some thunderstorms become organized and possibly back-build.
Over Newfoundland, beneath the upper trough, storms are likely to remain fairly stationary, with little shear available for organization. One possible concern is the development of thunderstorms across northern regions, with new storms forming along a potential land-sea boundary. However, under these very low-shear conditions, it is challenging to determine where storm activity will become most dominant. Torrential downpours and strong wind gusts will be possible with these storms.
Tomorrow, we will see the return of much stronger dynamics as the upper-level jet and stronger shear come into play. The biggest issue will be the timing of cap erosion. Should strong cells move into northwestern New Brunswick tomorrow afternoon—likely later in the day—there is a good chance these storms will exhibit significant mid-level rotation. Damaging winds and even tornadic storms cannot be ruled out.
There remains some uncertainty, but Canada Day has the potential to be problematic from late tomorrow into the evening, especially across northwestern New Brunswick.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
Mel Lemmon