Regional Impacts
Today
NS/PEI/NB: Likely for scattered thunderstorms. Hazards: 50-70 km/h wind gusts; 0-1 cm hail; 20-40 mm rainfall.
NFLD: Chance for isolated thundershower(s). Hazards: 15-25 km/h wind gusts.
LAB: Slight chance for isolated thundershower(s).
Tonight
NB/NS/PEI/NL/LAB: No thunderstorm risk expected.
Tomorrow
NB: Chance for isolated thunderstorm(s) over Northwestern NB.
NS/PEI/NFLD/LAB: Nil.
Convective Discussion
Today's surface analysis shows that there is predominantly an upper trough over the Maritimes which will act as a trigger for convection today. The most significant hazard is expected to be rainfall rates approaching 40mm/hr. This is largely due to the high PWAT's near 35mm still in play over most of the Atlantic Provinces. For Newfoundland and Labrador, there remains the same synoptic setup however there is expected to be a degradation in both trough strength and PWAT's over the island of Newfoundland. Over the Maritimes, specifically in the regions under the “B” location can see CAPE values nearing 1200 J/Kg meanwhile in Newfoundland, specifically in the southwest can also see CAPE values nearing 1000 J/Kg. Within this trough on the Eastern side of the trough there is jet support at the 500mb level nearing 40Kt and at the 250mb there is a stronger jet nearing 100Kt. On the western side of the trough there is a similar jet support at the 500mb level though at the 250mb level the jet drops down to a modest 60Kt.
As the trough passes through tonight, slight ridging is expected to build in, this combined with a fast approaching nighttime there is no convection anticipated over the Atlantic provinces.
An approaching cold front that is currently over Lake Superior, is expected to start impacting Northwest New Brunswick late in the day on Thursday. There is some uncertainty with the timing currently, but previous outlooks have indicated that there is a potential for strong winds and hail with this front. The area in Grey is given this as the timing uncertainty would cause a large variance in what is and is not possible during the designated timeframes.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
Forecaster: Lambert