Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

Today:

NB: Chance of thunderstorms giving locally heavy rain and strong wind gusts.

NL: Slight risk on a thundershower over the northern Peninsula

NS/PEI/Labrador: None.

Tonight:

NB/Gulf waters: Chance of embedded thunderstorms.

NS/PEI/NL/Labrador: None.

 

Tomorrow:

None.

Convective Discussion

A deep upper trough over central Quebec with a surface low pressure system currently over northwestern New Brunswick with track eastward today across the northern Gulf of St. Lawrence and into the Labrador Sea tomorrow. Embedded thunderstorms have moved across northwestern New Brunswick this morning ahead of the low, and further convection may fire along the cold front, which will move across New Brunswick this afternoon and evening. Meanwhile, along the warm front there has been isolated strikes across northern Newfoundland and the risk will continue into the early afternoon. The air mass in the warm sector is quite humid with dew points exceeding 20C. With a stalled ridge across northern Quebec into Labrador, ahead of the low, rainfall amounts are expected to reach upwards of 70 mm.

Along the cold front, thunderstorms will trigger this afternoon into the evening across New Brunswick into the Gulf waters with heavy rainfall being the biggest threat with precipitable water reaching 45 mm. Mixed CAPE values across northern New Brunswick may reach 500 J/kg if we get some clearing, and with effective shear of 30 to 40 kt, some organization is possible into line segments capable of producing strong wind gusts.  Storms will move fairly quickly towards the northeast under a 40 kt 700 mb flow.  Some overnight convection may hold across eastern New Brunswick and over the Gulf before the threat weakens overnight and into tomorrow.

Tomorrow the low continues eastward into the Labrador Sea and a ridge moves into the Maritimes with no thunderstorms are expected at this time.   

Thunderstorm Outlook for TODAY

Thunderstorm Outlook for TONIGHT

Thunderstorm Outlook for TOMORROW

 

 

Roberta McArthur

 

 

 

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts…

 

Today

NB: Chance of non-severe thunderstorms.

Labrador: Chance of embedded thunderstorms.

NS/PEI/NL: None.

 

Tonight

NB/NS/PEI/NL/Labrador:  None.

 

Thursday

NB: Chance of non-severe thunderstorms.

NS/PEI/NL/Labrador: None.

 

Convective Discussion

A low pressure system will move across northern Labrador today. A frontal boundary will extend southwest from the low into the St. Lawrence River Valley. Isolated thundershowers will be possible along this boundary this afternoon over northwestern New Brunswick. Limited CAPE should keep anything from getting too organized. Over Labrador some embedded thundershowers are possible today. On Thursday, a low pressure system will track from the Great Lakes toward the St. Lawrence Valley. Severe weather is likely over portions of New England and southern Quebec however once again limited CAPE should keep it to just a risk of thundershowers over northwestern New Brunswick on Thursday. Increasing precipitatal water values may allow for periods of heavy rain for northwestern New Brunswick Thursday afternoon and into the evening.  

Thunderstorm Outlook for Today

Thunderstorm Outlook for Tonight

Thunderstorm Outlook for Tomorrow

 

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts…

 

Today

NL: Chance of non-severe thunderstorms.

NB/NS/PEI/Labrador: None.

 

Tonight

NB/NS/PEI/NL/Labrador:  None.

 

Wednesday

NB: Chance of non-severe thunderstorms.

Labrador: Chance of embedded thunderstorms.

NS/PEI/NL: None.

 

Convective Discussion

A trough will track across Newfoundland later today. Isolated thundershowers are possible ahead and near the trough over northeast Newfoundland this afternoon. Limited CAPE will keep anything from getting too organized. On Wednesday, a low pressure system will move into Labrador, with a frontal boundary extending from the low back into the St. Lawrence River Valley. Isolated thundershowers will be possible along this boundary Wednesday afternoon over extreme northwestern New Brunswick. Limited CAPE should keep anything from getting too organized. Over Labrador some embedded thundershowers are expected on Wednesday.

 

Thunderstorm Outlook for Today

Thunderstorm Outlook for Tonight

Thunderstorm Outlook for Tomorrow

Convective Outlook Valid for Today, Tonight and Tomorrow

For June 15^th, 2025

 

Regional Impacts

 

Today: Some scattered thunderstorms possible in southeast Labrador today, main threat is strong wind gusts. Isolated chance of a thundershower over north-central Newfoundland and west-central New Brunswick this afternoon.

 

Tonight: No thunderstorms expected.

 

Tomorrow: No thunderstorms expected.

 

Tuesday: Slight risk of a thundershower over north-central Newfoundland on Monday afternoon.

 

Convective Discussion...

 

A few areas of interest are at play today, with the most prominent being southeast Labrador. Here, scattered thunderstorms are expected to develop in the warm sector this afternoon ahead of an approaching cold front moving through the region. Modest mixed-layer CAPE and effective shear will aid in the organization of some of these thunderstorms, however a lack of surface moisture and very dry low-levels will likely keep storms fairly elevated. Strong dynamics over the region may be enough to support an isolated supercell given enough CAPE, though this risk is low. As such, strong winds are the main hazard with these storms, with gusts of 70 to 80 km/h possible. Small hail and some locally heavy downpours are also possible.

 

In addition, a few isolated thundershowers are possible in west-central New Brunswick and north-central Labrador this afternoon under a diverging 500 mb jet with some embedded pockets of weak vorticity. Low CAPE and minimal shear will keep these storms from becoming organized and are not likely to be very long-lived, however some locally heavy downpours will be possible.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

 

Thunderstorm Outlook for Tuesday

 

Forecaster: Copp

 

Convective Outlook Valid for Today, Tonight and Tomorrow

Today: Isolated non-severe thundershowers possible over central Nova Scotia and south-central Labrador this afternoon. Main threat is brief heavy downpours, with no significant accumulations.

Tonight: No thunderstorms expected.

Tomorrow: Isolated risk of a thundershower along a cold front extending from Labrador to New Brunswick tomorrow afternoon.

Monday: No thunderstorms expected.

Convective Discussion...

A fairly quiet day is expected today, with a few areas that may see a couple lightning strikes this afternoon. First, a weak shortwave moving across New Brunswick this morning will pass over PEI this afternoon, triggering some showers along the Cobequids in central Nova Scotia. Higher dewpoints and a slight upslope enhancement are expected to aid in convection here today. These showers will have a slight chance to produce a lightning strike or two as they move east, however very little shear and minimal CAPE will likely inhibit the lifespan of these cells.

A second weak shortwave moving southeast along the Labrador coast is producing some scattered showers today across south-central Labrador. Some stronger low and mid-level jets over this region highlight the risk for some of these showers to produce some lightning strikes early this afternoon, though this risk remains low.

Tomorrow, a weakening cold front moving across Atlantic Canada may trigger some thundershowers in parts of New Brunswick and Labrador, but at this time the risk is low.

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

 

Thunderstorm Outlook for Monday

 

Forecaster: Copp