Regional Impacts
Today
NS: Chance for embedded thundershowers across Cape Breton early this afternoon and isolated thundershowers in northern Nova Scotia this afternoon with brief wind gusts and a risk of small hail.
NB: Chance of isolated thundershowers in the southeast in the afternoon with a risk of brief wind gusts and small hail.
NFLD: Chance for elevated thundershowers.
PEI/Lab: None.
Tonight
Isolated embedded thundershowers over the Grand Banks and southern NL
NS/NB/PEI/LAB : None
Tomorrow
NB/NS: Isolated to scattered thundershowers giving brief strong wind gusts and small hail.
NL: Isolated embedded thundershowers over the Avalon Peninsula.
LAB/PEI: None
Convective Discussion
Today, a frontal system currently across the Gulf of St. Lawrence will slowly progress eastward and begin to slow down over Cape Breton and Southern Newfoundland tonight. The risk of embedded convection continues along the trough today and tonight. In behind the frontal system, clearing of the cloud with still moderate dew points will aid in increasing instability in the afternoon. There is a narrow corridor of Mixed CAPE nearing 500 J/Kg with effective shear of 20 to 30Kt due to an 850 mb LLJ giving rise to the possibility of some organized thundershowers from Southeast New Brunswick into central Nova Scotia late afternoon and early evening. Brief strong wind gusts and small hail less than 1 cm are expected.
Tomorrow, a weak ridge over the Maritimes will erode, and with the aid of increasing moisture and convective temperatures along with an approaching jet streak from the west and sea breeze convergence, isolated to scattered showers with a risk of thundershowers will develop in the afternoon. The highest risk of storms is over central and northern New Brunswick, where freezing levels are fairly low and MUCAPE values are expected to reach 1500 J/kg. Shear is only light to moderate at or below 20kt, so expecting more pulse like storms with brief wind gusts, heavy rain and small hail of 1-2cm. Seabreeze convergence may also aid in a brief showers in the spine of NS, PEI and southern NB.
The risk of embedded thundershowers continues along the trough across the Avalon southeastward towards the Grand Banks as well tomorrow as the trough slowly pulls away to the southeast.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
Forecaster: McArthur