Thunderstorm Outlook for Today
Isolated non-severe thunderstorms
Regional Impacts
Clusters of thunderstorms will likely develop over western and central Labrador.. producing heavy showers and some wind gusts to around 70 km/h.
Risk of a thunderstorm over northeastern Newfoundland.
Convective Discussion
At the surface this morning is a low pressure area over the south coast of NF with extensive cloud and rain associated with it. The frontal boundary is supported by a southwesterly upper jet crossing the Avalon. The YJT sounding is saturated but Satellite imagery is showing some breaks in the clouds along the south coast. MUCAPE values are indicative of a potential for convection over parts of the island. Some limited surface heating may help the development of Cu/Tcu, and with the frontal boundary / upper jet / some pva at 500mb.. there is a risk that these convective clouds could evolve into CB’s.
Another area of focus today will be south of Ungava bay with a cold front southwestward. Surface CAPE values could reach 500 J/Kg ahead of this feature during the afternoon, modified LaGrande sounding indicates the potential for heavier showers and wind guts between 30-40kt.
Thunderstorm Outlook for Friday
A new low pressure will emerge from the northern Quebec frontal boundary and become established over Labrador Friday. A cold frontal band will stretch southwestward from the low and swing across the Maritimes. There is a potential for mixed-layer CAPE values of more than 500J/Kg, Lifted indices of -4, and deep layer shear of 30+Kt, all of which could lead to some bowing lines over central and northern NB.
