Convective Discussion
A broad upper low over Newfoundland and eastern Labrador will slowly drift to the northeast today. A more concentrated area of convection this morning over the southeastern Grand Banks will continue off to the north and east this afternoon. With some partial clearing this morning over central and eastern Newfoundland and Labrador, convective temperatures are expected to be reached along with a bit of cooling aloft which will further destabilize the atmosphere and help to generate some convection this afternoon. CAPE values in to 200-500 J/kg range along with some weak to moderate shear and sufficient low level moisture will help to sustain convection. With freezing levels below 10,000ft, some small hail along with locally heavy rainfall is not out of the question.
Meanwhile, a more potent low pressure system currently over James Bay will be advancing eastward over northern Quebec today with a trough of low pressure extending southward. A warm front will begin to affect parts of western Labrador this evening and overnight with some embedded thundershowers along it. Some embedded thundershowers are also possible early tomorrow morning for western Labrador with a very slight risk over western New Brunswick as the trough of low pressure associated with the low pressure system continues to advance eastward.
Regional Impacts
Labrador…
Locally heavy downpours, small hail and brief strong wind gusts are possible this afternoon over parts of central and eastern Labrador.
Newfoundland…
Locally heavy downpours, small hail and brief strong wind gusts are possible this afternoon over parts of central and southeastern Newfoundland.
Maritimes…
No convective weather expected today. However, a very slight risk of an embedded thundershower is possible early tomorrow morning over western New Brunswick with locally heavy downpours.
Roberta McArthur
