Regional Impacts
Today:
LAB: Risk of thunderstorms late this afternoon with locally heavy downpours and strong wind gusts.
Maritimes/NL: None
Tonight:
LAB/NB: Risk near-severe embedded thunderstorms this evening giving locally heavy downpours and strong wing gusts.
PEI/NS/NL: None
Tomorrow:
LAB: Risk of near-severe thunderstorms with heavy downpours, small hail and strong wind gusts.
NB: Risk of a thunderstorms giving locally heavy downpours and strong wind gusts.
PEI /NS /NL: None
Convective Discussion
A low pressure system over James Bay this morning has a trailing cold front stretching from central Quebec into the eastern USA. Thunderstorms along and ahead of the front may reach western Labrador and northwestern New Brunswick by early evening with the threat continuing into the evening. This front will continue to stream in precipitable water into the 40-50 mm range even as far as northern Labrador over the next few days. However, some smoke notes aloft over the region may work to inhibit full daytime heating potential. The highest risk of severe thunderstorms remains over southern to central Quebec where with cooler air aloft, and a strong 850mb jet. Regardless, heavy downpours and strong wind gusts may continue into the overnight for western New Brunswick and western to central Labrador.
Tomorrow, the front will continue to track eastward further north over Labrador. With CAPE potentially reaching 1000 and moderate effective shear reaching 35-40KT, lines may organize into lines in the afternoon ahead of the cold front over central and eastern Labrador. Behind the front, a shortwave is expected to quickly track across central Quebec and into western Labrador by the evening. With this, there could be further multicell convection with strong wind gusts being the main threat with a drier air mass.
Meanwhile further south, a slow moving low pressure system and ridge over the southern marine waters will keep the threat of convection mainly over north and western New Brunswick. Locally heavy rain and strong wind gusts would be the main threat with convection that can continue from northern Maine.
Thunderstorm Outlook for TODAY
Thunderstorm Outlook for TONIGHT
Thunderstorm Outlook for TOMORROW
Roberta McArthur