Regional Impacts
Maritimes: Scattered thunderstorms today, with some discrete cells possibly reaching severe limits for moderate hail, and rain. (Funnel clouds are possible).
NL: Embedded thundershowers within a greater area of showers/rain.
Convective Discussion
Dynamics at play over Newfoundland today include a trough line generating instability over the island. Precip is likely to be in the rates of 5-10mm, and these cells are moving quite quickly to the north. Winds gusts locally may reach near 60 to 70 km/h. Both CAPE and Shear are much more favourable for thunderstorm development over portions of the Maritimes. In SW NS, ML CAPE of 500-800 is present, and convective trigger temps will easily be surpassed with the cloud holes that are developing this morning. In central and SE NB, MLCAPE is 760-1000 J/kg, with Effective Shear of 25-30kts in the lower levels. Lapse rates of -6 were analyzed this morning, as the upper low feature continues to destabilize this air mass. SFC dew points of 12-16 are observed as the morning fog burns off. This upper trof is very important to watch as it sweeps through the AOR this afternoon. Helicity values (similar to those near Hants county yesterday) will be present near Moncton and Shediac late this afternoon. As such, there is a *non-zero chance of a funnel cloud or non-supercell tornado* in this area. However – the chance is very low, and it is not included on the graphical depiction because of the low likelihood and low severity. Watches will be used to alert the public if required. Another advancing trough will bring a line of convection up from the south Saturday evening, over the marine areas and affecting NS’s south and Acadian shores.
Thunderstorm Outlook for TODAY
Thunderstorm Outlook for TONIGHT
Thunderstorm Outlook for SATURDAY
Forecaster: J. TIRONE/ASPC