Atlantic Canada Weather Blog: Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

Today:

Labrador: Non-severe risk of a thundershower in south-central Labrador.

Maritimes and Newfoundland: Nil

Tuesday and Tuesday night:

Maritimes: Risk of embedded TS with rainfall of 10 to 20 mm.

Convective Discussion

Slight risk of a thundershower today along a trough extending from central Quebec southeastward across Labrador that will move southeast and weaken by tonight. Goose Bay sounding shows a cap between 700 and 500 mb that is not likely to be breached, so mainly expecting on TCUs but the cap may be broken south of the public regions. Upper smoke from fires over central and western Canada continues to linger across Atlantic Canada, also adding to the unlikelihood of exceeding the necessary surface heating.

Tomorrow, a trough associated with a low pressure system over James Bay will bring a broad destabilization with cooling aloft throughout the day. There will likely be enough lift near 850 mb from a 35 KT LLJ to generate embedded thunderstorms across western New Brunswick and Nova Scotia by early evening and into the overnight. Moderate to heavy rain in possible across the Maritimes as higher precipitable water of 30 to 40 mm comes in from the Gulf Stream.

The trough moves into Newfoundland on Wednesday and behind and south of the low as if tracks over northern Quebec will enable pop-up convection over western Labrador.

Thunderstorm Outlook for TODAY