Regional Impacts
NS/NB… Scattered thunderstorms possible today. Main hazard is torrential downpours of 25 to 50 mm/h.
PEI… Isolated embedded thunderstorms possible this afternoon. Main hazard is locally heavy downpours of 15 to 25 mm/h.
NL… None
Convective Discussion…
A strong moisture plume from the remnants of Hurricane Beryl will move across the Maritimes today, bringing the risk for some scattered thunderstorms to parts of Nova Scotia and New Brunswick. A few thunderstorms have already developed in Maine this morning and have moved across the international border into New Brunswick. Watches have been issued for southern New Brunswick, and will likely be expanded into Nova Scotia this afternoon. This risk for severe storms will continue into this afternoon, especially along the Bay of Fundy, where good low level moisture flow will help fuel storms that fire along the 500 mb jet as it slowly moves east. One of the big challenges today however will be achieving sufficient instability. Models have backed off on MLCAPE values, likely due to increased cloud cover over the southern Maritimes, as well as the stalling of the thermal trough over New England. This should keep the risk for severe weather over and around the Bay of Fundy, though given sufficient clearing, there is a slight risk that some severe storms could fire in southwestern Nova Scotia. Dynamics will not be an issue today, with bulk shear values of 45 to 50+ kts. PWAT values have been observed to be between 50 to 60 mm based on the 12Z Yarmouth and Gray soundings. As such, the main hazard with any storms today are torrential downpours of 25 to 50 mm.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
Copp