Regional Impacts
Today
NB: Chance for an isolated thundershower.
LAB: Slight chance for an isolated thundershower.
NS/PEI/NB/NFLD: Nil.
Tonight
NB: Chance for isolated thundershowers.
NS/PEI/NFLD/LAB: Nil.
Tomorrow
NB: Likely chance for severe thunderstorms. Most significant hazards: a possible tornado; 1-2 cm hail.
NS/PEI/LAB: Likely chance for isolated thundershowers.
NFLD: Nil.
Convective Discussion
After an active upper trough moved through Atlantic Canada, today is expected to be relatively quiet as a ridging is in place over most of the Atlantic provinces. There is however a progressing frontal system moving through Quebec which is giving some short waves passing through Labrador today with enough jet support to have Effective shear values nearing 25KT which could support some isolated thunderstorms is they form. For New Brunswick, there is the chance that prefrontal thundershowers form over the extreme Northwestern sections of the province. But they are currently not expected to become severe.
Overnight with the approaching frontal system from Quebec there is the chance of isolated thundershowers off the southern Coast of New Brunswick and Nova Scotia which could drift inland over New Brunswick.
Tomorrow, the frontal wave is sweeping through the Maritimes giving a collection of ingredients for severe thunderstorms to have a chance at forming. As the cold front progresses through the Maritimes, effective shear values are expecting to be near 40KT along with having a classically curved hodograph and ample low-level helicity it is possible that a tornado or two could form tomorrow. Additionally, looking at soundings the risk for hail is likely to be near 1-2cm. It is worth noting that some sounding analogues do indicate over 2cm of hail, so it is something to keep in mind for tomorrow, but it does appear unlikely to have hail this significant.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
Forecaster: Lambert