Thunderstorm Outlook for Day 1
Regional Impacts
New Brunswick and western Nova Scotia: Depending on cloudiness, possibility of thunderstorms east and severe thunderstorms west, with heavy downpours the greatest threat, followed by gusty winds.
Northern Newfoundland and southeastern Labrador: chance for non severe thunderstorms,
Convective Discussion
The synoptic situation is similar to yesterday, with a low near Hudson Bay and a second over the Labrador Sea, with an extended east-west trough between them and over Labrador. This also produces slight ridging over Quebec and New England. For Newfoundland and Labrador there is some support for non-severe convection near the Strait of Belle Isle. Some weak PVA from a jet right exit, combined with daytime heating may give a few cells. PWAT is only about 20 mm., but CAPEs in excess of 200 J/kg with a slight chance of 500 J/kg are possible. Gusty winds and brief heavy showers are the main issues, with a slight chance for hail with YYR having freezing levels below 8000 ft.
For the Maritimes things are trickier. Cloudiness will be the key. There’s some upper support from a 500 mb jet near southwestern New Brunswick with some associated lift, with plenty of moisture below 700 mb. PWATs range from 40-60 mm, with surface dewpoints near 20 C, and 850 dewpoints up to 15 C , with a moist tongue poking into southern New Brunswick. If things clear, CAPEs of up to 1000 J/kg or maybe higher are possible. Freezing levels near 15,0000 ft suggest large hail is unlikely. Very heavy rainfall is the largest risk, followed by gusty winds that may reach warning level, and finally some small hail. For the rest of New Brunswick and parts of Nova Scotia, the impacts will be somewhat weaker, but rainfall followed by winds as the main risks.
Thunderstorm Outlook for Day 2
