Regional Impacts
Today
NL/NS/NB/PEI/LAB: None
Southeastern Marine waters: Lightning and reduced visibility in heavy downpours.
Tonight
NL/NS/NB/PEI/LAB: None
Southeastern Marine waters: Lightning and reduced visibility in heavy downpours.
Friday
None
Convective Discussion
The UA at YYT this morning revealed the same tropical air mass that was in place across the Maritimes yesterday, with PWATs near 50mm. Instability exists aloft at ~850 mb but MUCAPE is limited (~150 J/Kg or less) due to some thermal ridging at the 500mb pressure level. This is also noted through the limited delta T between the 700 and 500mb levels of ~11-12 C, indicative of very little mid level instability. For this reason the no lightning is expected of land areas of eastern NL, however across the marine areas to the south and east of the Avalon higher MUCAPEs upwards of 500 J/Kg exist, and this should allow sufficient buoyancy and charge separation to produce isolated to scattered lightning today and tonight. Primary hazard for these mariners will be sharply reduced visibility in downpours.
By Friday this air mass is expected to move well to the east of the region and associated marine waters, with a much drier and stable air mass in its wake. Stable conditions across Atlantic Canada are expected to last through Saturday at this time with no thunderstorms activity.
Thunderstorm outlook for today:
Thunderstorm outlook for tonight:
Thunderstorm outlook for Friday:
Allen