Convective Discussion
Atlantic Canada is mainly under the influence of a ridge of high pressure today which will suppress convection over the Maritimes. Sea breeze convergence will provide some lift and isolated showers are possible for Newfoundland this afternoon and evening. There is a weak upper level trough over North Shore Quebec moving eastward towards southern Labrador today which will provide further instability with some cooling aloft. In addition, some coastal convergence and upslope flow will help to produce some isolated thundershowers this afternoon over central and southeastern Labrador. Given only weak shear, locally heavy downpours will be the main threat. With CAPE values of around 250 J/kg and freezing levels near 8,000ft in the area, there is also a slight risk of small hail.
Regional Impacts
Labrador
South central and eastern Labrador – Risk of thunderstorms with heavy downpours and a slight risk for small hail.
Maritimes and Newfoundland
None expected
Roberta McArthur