Day 1 Convective Outlook for Atlantic Canada Valid for June 1, 2018

 

Convective Discussion

 

A warm and increasingly humid air mass is approaching New Brunswick today ahead of a low pressure system over Labrador with a cold front extending into central Quebec. The atmosphere will be conducive for the development of thunderstorms in the afternoon given falling 500mb heights, increasing moisture in the low levels and high maximum temperatures. These ingredients along with the approaching cold front will help de-stabilize the air mass and initiate showers and thundershowers over northwestern New Brunswick beginning in the afternoon and spread southeastward into the evening. Due to the high precipital water content in this air mass and not much wind aloft, showers that develop will move slow and local heavy downpours are possible. The risk of thundershowers may continue into Nova Scotia overnight.

 

Regional Impacts

 

The main threat with the thundershowers will be locally heavy downpours (20-40mm possible).

 

 

Roberta McArthur

 

 

Day 2 Convective Outlook for Atlantic Canada Valid for June 1, 2018

 

Convective Discussion

 

A warm and humid air mass will approach New Brunswick on Friday ahead of a low pressure system moving eastward over Quebec. The atmosphere will be conducive for the development of thunderstorms in the afternoon given increasing moisture in the low levels, moderate low level wind shear and high maximum temperatures. These ingredients along with an approaching cold front will help de-stabilize the air mass and initiate afternoon showers and potential thundershowers over northwestern New Brunswick beginning in the afternoon and spread southeastward into the evening.

 

Regional Impacts

 

The main threat with the potential thundershowers will be local heavy downpours and some moderate gusts.

 

 

Roberta McArthur

 

 

Day 1 Convective Outlook for Atlantic Canada Valid for May 31, 2018

 

Convective Discussion

 

No convection expected in the Maritimes and Newfoundland today mainly due to a warm but dry airmass providing wide scale subsidence under a ridge of high pressure. Meanwhile, a warm front is beginning to slide further east into Labrador giving rain overnight to western Labrador. Convection may be enhanced overnight due to nocturnal cooling but at this time thunderstorms are not expected.

Regional Impacts

 

None

 

 

Roberta McArthur

 

Day 1 Convective Outlook for Atlantic Canada Valid May 30th, 2018

 

Convective Discussion

 

No convection expected in the Maritimes and Labrador today due to a warm, dry airmass providing wide scale subsidence under a ridge of high pressure. There are showers over eastern Newfoudland  as a low pressure system spins off the eastern coast of Newfoundland but the airmass remains to stable for thunderstorms to develop.

 

Regional Impacts

 

None

 

 

Roberta McArthur

 

Day 1 Convective Outlook for Atlantic Canada May 29, 2018

Convective Discussion

Very dry air mass with warm air aloft combined with subsidence due to approaching high pressure will likely result in no convective activity today for the Maritimes.

There are showers currently over NFLD but the air mass is too stable for any thundershowers to develop.

 

Regional Impacts

None

 

Barrie MacKinnon

Roberta McArthur