Regional Impacts
TODAY
NS+NB+PEI: Widespread thunderstorms and synoptic rain is advancing from west to east early in the day as forecast. Hazards – lightning, and heavy rain has been observed. A local rainfall warning and SWS remain in effect at this time.
Annapolis Valley of NS: Repeated rounds of convection continuing this afternoon. Hazards – torrential rain possible. Watches may be required if atmosphere destabilizes further.
TOMORROW
Gulf waters and Nfld: Thunderstorms with high mid-level moisture leading to persistent heavy rain. Hazards – heavy rain.
Convective Discussion
Ongoing convective rain is spreading across the Maritimes as the trof moves east. The jet axis placement is a very important feature today. Heaviest rain is falling just north of it. And a second round of convection is forecast to develop south of it. This axis at 10am lies across the Bay of Fundy. Rain in NB will end from west to east this afternoon. Rain in PEI will continue for much of today. Northern and central NB will see convection bubble up again under a partial clearing this afternoon. LL helicity in the Keji area of NS will play into the strength of possible squall line this afternoon that the HRRR depicts, if it can hold together. LL moisture is ambient, and mid-level moisture is also over 40. These dynamics drift over Gulf of St Lawrence waters tonight and into Nfld tomorrow morning. Heavy rain is the expected hazard on day 2. Isolated waterspout formation across eastern maritime marine areas is also likely this evening and tonight. A watch may be issued this afternoon for marine interests.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for SATURDAY
Forecaster: TIRONE