Convective Discussion
Near severe thundershowers possible for northern New Brunswick, with non-severe thundershowers possible for much of the Maritimes. Thundershowers possible for western Labrador and the Maritimes.
Maritimes: These will be mostly air mass driven by daytime heating up to the low thirties and dew points near 15-20 C . A deep ridge will move though New Brunswick this afternoon and over eastern Nova Scotia by this evening, having generally sunny conditions. CAPEs near or possibly exceeding 500 J/kg range are reasonable for the Maritimes provinces, with New Brunswick possibly in the 500-1000 J/kg range, and possibly higher central and north. The highest risk are for heavy downpours and high wind gusts. The main factors against these cells developing is a lack of moisture aloft, as well as a lack of upper support. 0-6 km shear is near 30 kts, and will diminish a bit this afternoon. Freezing levels near 13 to 15 thousand feet make significant hail unlikely.
Labrador: For western Labrador there are two factors that may spawn some weak cells this afternoon, that may become healthier into early this evening. . Near or just east of Churchill falls there is a north-south trough with some sunny breaks to the west. Farther west there is a weak diffluent upper jet approaching from Quebec. These, combined with daytime heating may produce some cells with CAPEs up to 500 J/kg, with PWAT near 33 mm, and dew points near 14 C in the west. Wind shear is near 25 kts and will increase from the west into this evening to near 35-40 kts.
Regional Impacts
New Brunswick: : Near severe thundershowers possible this afternoon into this evening with heavy downpours and gusty winds possible. Highest risk for severe in the north this afternoon.
Nova Scotia: Non-severe thundershowers possible this afternoon into this evening with heavy downpours and gusty winds possible.
Prince Edward Island: Non-severe thundershowers possible this afternoon with gusty winds and occasional heavy downpours.
Labrador: Non-severe thundershowers giving occasional downpours. A slight chance for small hail.
Newfoundland: None
Doug Mercer