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Thursday, May 31, 2018

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

 

Wednesday, May 30, 2018

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

 

Tuesday, May 29, 2018

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

 

Monday, May 28, 2018

Day 1 Convective Outlook for Atlantic Canada May 28, 2018

Convective Discussion

Risk of non-severe thundershowers tonight over New Brunswick as a cold front sweeps across the province.  If any thundershowers develop, they should begin near midnight over northwestern New Brunswick then track southeastward with the front.  Stability is quite low so thundershowers are expected to remain below warning criteria.  Nocturnal cooling could help with the development of thundershowers but even then should not reach warning criteria.

Regional Impacts

Localised heavy short lived showers with up to 10 mm possible,  small chance of hail below 2 cm and wind gusts of up to 40 km/h.  



Barrie MacKinnon


Thursday, May 17, 2018

Changes to the Convective outlook



For this convective season we will be moving to the Ninjo depiction of the convective outlook and away from the AMX version which we have been using. The color scheme will be very similar to what we used last year however new Ninjo version has a much cleaner look. One main difference will be that the convective discussion will be in the body of the email below the convective outlook image. In addition we will try to break our discussion into two sections with a Technical synopsis and and Regional Impacts, as required. Below is an example the what the new outlook will look like as well as one from last year for comparison. In general this should provide some consistency with Quebec region, however our regional SOP’s will vary the our images may not match up everytime. For the Atlantic region the color breakdown will generally be as follows.


GRAY - Risk of Thunderstorms: Thunderstorms that develop in this area will generally be less organized and will not likely meet warning criteria. Severe Thunderstorm Watches will not likely be required.

YELLOW - Slight Risk of Severe Thunderstorms: There is a low probability that weakly organized thunderstorms will develop, these thunderstorms may reach warning criteria. Severe Thunderstorm Watches may be required

ORANGE - Moderate Risk of Severe Thunderstorms: There is a moderate probability that organized thunderstorms will develop, thunderstorms are likely to reach warning criteria. Severe Thunderstorm Watches will likely be issued.

RED - High Risk of Severe Thunderstorms: There is a high probability that well organized thunderstorms will develop, these thunderstorms are likely to meet or exceed warning criteria. Severe Thunderstorms Watches will be issued.


*Not the actual depiction for this Date

Technical Synopsis……


Regional Impacts……



Old Convective Outlook


Tuesday, May 15, 2018

Convective Outlook for May 15th, 2018


There is a slight risk of thunderstorms across southwest Nova Scotia later this afternoon and this evening. This will be mainly in the form of elevated convection and even though there are strong winds aloft there is very little wind shear through the convective column. There is a slight chance that some stronger gusts could reach the surface but it is unlikely that they will approach warning criteria.