Regional Impacts
Today
NL/NS/PEI: isolated thundershowers giving locally heavy downpours.
Labrador: isolated to scattered thunderstorms possibly giving strong winds and small hail in the west.
NB: scattered thunderstorms possibly giving strong winds, hail and heavy rainfall.
Tonight
NL: isolated thundershowers giving locally heavy downpours
Wednesday
NL: isolated thundershowers.
Convective Discussion
None of the upstream TEPHIs are going to give the air mass moving into western NB any justice since the prime location is east of Maniwaki and north of Grey ME. But a fairly sharp and digging upper trough (and associated surface front) is evident in WV imagery this morning over Quebec and is already initiating some storms. The 12Z KCAR profile shows about 40 knots of westerly shear but is moist given the precipitation at the time of the launch. Things dry rapidly in the mid-levels not far upstream and, combined with MLCAPE up around 1000 J/Kg will generate some strong to possibly severe cells this afternoon and into the evening. Freezing levels are pretty high but will be lowering and since the CAPE is fairly “fat” some of the stronger updrafts could support some 1-2 cm hail. PWATs are high with ample low level moisture and TDs around 20 will give a threat to torrential rainfall as well. A thickness ridge currently moving across the MRTMS will enter NL this afternoon with perhaps an isolated embedded thundershower associated with it. There could be an isolated strong to possibly severe cell that may impact the Churchill Falls and Lab West/Wabush areas this afternoon giving strong winds and small hail. There is already convection upstream over Quebec so will also have to keep an eye on things up in the Big Land.
Thunderstorm Outlook for Day 1
Thunderstorm Outlook for Day 1 night/Day 2 morning
Thunderstorm Outlook for Day 2 afternoon
Jeremy