Regional Impacts
Today
NB/PEI: Slight chance for isolated thunderstorm(s). Hazards: 70 km/h wind gusts; 0-1 cm hail; 15-25 mm rainfall.
LAB: Slight chance for isolated thundershower(s).
NS/NFLD: Nil.
Tonight
PEI/NS/NFLD: Chance for isolated thundershower(s). Hazards: 70 km/h wind gusts; 15-25 mm rainfall.
NB/LAB: Nil.
Tomorrow
NFLD: Slight chance for isolated thundershower(s).
NS/PEI/NB/LAB: Nil.
Convective Discussion
Looking at today's surface analysis, there is a low off the coast of Labrador along with a cold upper low over Northern Quebec into Labrador. Additionally with this setup we have two significantly strong curved jets, a 55KT jet at 500mb and a 95KT jet over northern New Brunswick. As the cold upper low progresses to the south with these jets, we can expect to see some isolated thunderstorms in New Brunswick, western PEI, and Southeastern Labrador. Looking at Surface based CAPE, we are seeing CAPE values remain mainly around 700 J/Kg with some isolated areas over NB and PEI reaching 1,000 J/Kg, over these areas we do have Effective Shear reaching 30 to 35Kt over most of NB and PEI.
With the progression of this system sweeping through the Maritimes and Newfoundland there is guidance to suggest that overnight thundershowers are possible over eastern PEI, Nova Scotia, and Eastern Newfoundland. It is worth noting that in this outlook we have a region "B" this is to denote the possibility of waterspouts. As the system moves over Nova Scotia, guidance is suggesting that it could develop into a squall line which if that occurs there is a possibility that waterspouts could develop. Overnight Most Unstable CAPE (MUCAPE) values are expected to stay within the range of 500 J/Kg, except over warm waters where they could approach the 1,000 J/Kg mark. Additionally shear values are still expected to remain near 30Kt over warm waters but reduce down to 20Kt over land.
Tomorrow will begin a relatively quiet period as this system should depart eastern Newfoundland early into the valid period of the outlook. Once this system had departed a ridge is expected to develop over most of Atlantic Canada.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
Forecaster: Lambert