Regional Impacts
Today:
NB/NS/PEI/NL: Risk of thunderstorms giving strong wind gusts, small hail and brief heavy downpours.
LAB: Risk of thunderstorms giving small hail.
Tomorrow
NB/NS/PEI/NL: Risk of a thundershower giving strong winds gusts and small hail.
LAB: Risk of a thundershower giving small hail.
Convective Discussion
An upper low over Labrador will become stacked today while a cold front continues across southeastern Labrador, Newfoundland and exits south of Nova Scotia this morning. While high level smoke prevented much of the anticipated convection yesterday, convection has been able to fire across southeastern New Brunswick, PEI and Newfoundland this morning where the smoke has cleared. Elevated convection across Newfoundland and the Maritimes marine waters south of Nova Scotia is also on the go this morning with the help of a 45kt low to mid level jet and a favourable upper jet. With dewpoints in the mid to high teens and precipitable water of 30-35, there is the risk of heavy downpours and possible small hail. East of the low, sufficient lift will aid in thunderstorms continuing across eastern Newfoundland and southeastern Labrador. Mixed CAPE of upwards of 750 J/kg and effective shear of 20 to 30 kt will allow convection to sustain.
Daytime heating with clearing skies and cooler air aloft will aid in the potential for convection continuing across eastern Nova Scotia, the southern Gulf of St. Lawrence and into central Newfoundland by the afternoon. Mixed CAPE may reach upwards of 1500 J/kg and with effective shear of 40 kt, cells that develop may organize into lines, with a small risk a supercell with sufficient low level helicity this morning. The drier air aloft entering from New Brunswick could lead to brief strong wind gusts in pop up convection across northern New Brunswick later this afternoon.
For tomorrow, a short wave trough from Quebec will track into New Brunswick and across the Maritimes in the afternoon. With relatively dry dew points still in the area under a west-northwest flow and reduced CAPE (500J/kg), the main threats will whatever develops will be brief strong wind gusts and small hail.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
