Day 1 Convective Outlook for Atlantic Canada Valid August 30, 2019

Convective Discussion

A cold front will approach western Labrador today. There is a slight risk of thundershowers late this afternoon.

Regional Impacts

Maritimes…

None.

Newfoundland and Labrador…

Risk of thundershowers for western Labrador.

Andy Firth

Convective Outlook Valid for August 27 2019

Convective Discussion

 

Isolated non-severe elevated CBs are expected near a surface low located southeast of Cape Breton which is moving slowly northeastward. These CBs will give embedded heavy downpours. Another area of non-severe elevated CBs is expected in the warm sector of the frontal wave over the southern Grand Banks, mainly near or just east of the cold front.

 

 

Regional Impacts

 

Nova Scotia: non-severe embedded thunderstorm for eastern parts of the province. Local heavy showers and some wind gusts.

 

Newfoundland/Labrador/Prince Edward Island/ New Brunswick: none.

 

Grand Banks: embedded convection east of the cold front of the low, weakening to the north over colder water.

 

 

 

 

 

 

Spencer Clements

Convective Outlook Valid for August 26 2019

Convective Discussion

Nothing expected for the Maritimes nor Newfoundland and Labrador land areas.

Basically, there is a large and deep ridge over Atlantic Canada, with a strong subsidence inversion pushing well south over the Scotian Shelf and the Grand Banks. There are other inhibiting factors, including low moisture and very low shear over most regions, but the inversion is the real killer. On Tuesday there is a slight chance of convection along southernmost areas of Newfoundland, and a lesser chance for Cape Breton.

For the marine areas to the south, there is a chance of convection, due to a small low moving up slowly  from south of the Scotian Shelf towards southwestern Newfoundland. Currently there is some convection mainly east and south of the low, with some surface based convection near and south of the warm front. As the low moves north over colder water, this will diminish, and there will be occasional embedded convection as it moves up tonight, again near and south of the warm front.

Regional Impacts

Atlantic Provinces: none today or tonight.

Southeastern offshore waters: non-severe thunderstorms over southernmost waters slowly moving north and weakening, mainly for Laurentian Fan and the southwestern Grand Banks. For southernmost waters of Laurentian Fan the Southwestern Grand Banks gusty winds are possible with CAPEs near 500 J/kg for southernmost Laurentian Fan and somewhat higher for the southern half of the Southwestern Grand Banks where it ranges from 500 to 1000+ J/kg.  Otherwise local downpours are fairly likely, with precipitable water near 50 mm in the south. Again. Convection will become embedded and weaken as the low moves north.

Doug Mercer

Convective Outlook Valid for August 25, 2019

Convective Discussion.

 

No activity expected in the region today.

 

Regional Impacts.

 

Nil.

 

 

Jeremy

Convective Outlook Valid for August 24, 2019

Convective Discussion.

 

Only some scattered cells across the southern Grand Banks and slope waters south of NS today in association with a trough of low pressure. Quiet weather elsewhere.

 

Regional Impacts.

 

NS/NB/PEI/Newfoundland/Labrador: nil