Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

Today

NB: Isolated non-severe thundershowers possible

NS: Isolated thunderstorms possible over southwestern sections of province – biggest hazard is wind gusts 60-75 km/h near a storm cell

 

Tonight

Atlantic Canada: None forecast

 

Saturday

Atlantic Canada: None expected

 

 

Convective Discussion

 

Embedded thundershowers are on the go this morning/early aft on the Bay of Chaleur coastline. Additionally, as the frontal feature leaves the St Lawrence river valley, a few cells are firing up outside of the greater cloud shield near the Maine border. These cells lack formal dynamics necessary for any significant development. 5-15mm of rain can be expected, locally. NS is a bit more interesting as a few more factors are at play this afternoon. Firstly, there is a lot of wildfire smoke in the mid-levels of the atmosphere. If this can be overcome, there is 300 J/kg of well mixed CAPE available from the Sackville area down to Yarmouth. Nothing will last very long near the coasts as water is still very cold this time of year. Storms today will be very high based, as the boundary layer remains unseasonably dry – albeit dew points are climbing since yesterday (now near 12-14). Shear is another limiting factor. There is very little shear. Anything triggered from this backdoor cold front will only transit along the front, and not for very long. Biggest hazards today are gusty winds (sub-warning) near a storm, small hail(less than 1cm) and lightning. Synoptic rain is on the way for the Maritimes this weekend and shuts of any further TS risk. Newfoundland’s weather remains dominated by a large re-circulating cloud shield.

 

 

Thunderstorm Outlook for TODAY

 

Thunderstorm Outlook for TONIGHT

 

Thunderstorm Outlook for SATURDAY

 

Forecaster: TIRONE

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

Today

NB: isolated thunderstorms.. potential for small hail and gusty winds

NS/PEI/NL&Lab: None

 

Tonight

NB#NS/PEI/NL&Lab: None

 

Friday

NB/PEI/NL&Lab: None

NS: slight risk of a thunderstorm westernmost regions  

 

Convective Discussion

The heat continues to build this morning, and as of this hour several stations in NB are reporting temperatures above 30 degrees. The ridge of high pressure over the region will begin to weaken signaling a threat for thunderstorm activity. The environment is charged with large amounts of CAPE in the mid and upper levels, mean layer CAPE in excess of 1000 J/kg. Convective trigger temperature runs between 32 to 35 degrees, and the upper range makes a significant difference on the outcome of the instability. The missing ingredient is moisture, however Td’s have been slowly increasing and current values range from 12 to 16 in NB, 10 to 12 in NS, and below 10 in NF. Given the amount of instability and lifting convective initiation will likely occur over the hills of northern and central NB, and then further south during the late afternoon. The towering clouds could evolve into CB’s with tops almost reaching the tropopause with sits at about 12km this morning. Deep layer shear values are 10-15kt limiting the possibility of any storm that forms of becoming severe. The main threat with these storms will be small hair and strong wind gusts.

 

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Friday

Convective Outlook Valid for Today and Tomorrow

Regional Impacts:

 

Today

Labrador: an isolated thunderstorm (brief heavy shower and gust 60km/h) in the Churchill Valley-Goose Bay-Eagle River areas

NB/NS/PEI/NL: None

 

Tonight

Labrador: convection slowly dissipating

NS/NB/PEI/NL: None

 

Wednesday

NS/PEI/NL: None

NB: slight risk of a thunderstorm  

 

Convective Discussion

A surface frontal band extends from the north Labrador coast to James Bay and then northern Ontario this morning. Mid-level convection embedded in the cloud produced some lightning activity last night. This feature will be advancing over the Atlantic provinces during the next couple of days producing a slight risk of thunderstorm over the region.

The main threat today lies across central Labrador.. upper air sounding from Goose Bay indicates plenty of instability and the surface moisture has been increasing since sunrise. Surface T/Td combination of 28/14 (MLCAPE 400 LI -3) is enough to trigger the odd high base pulse thunderstorm which could give a brief heavier shower and gust to 60 km/h. Upper support for this activity is not very good so any storm that forms will not last very long.

 

 

Thunderstorm Outlook for today

 

 

Thunderstorm outlook for tonight:

 

 

Thunderstorm Outlook for Thursday

Convective Outlook Valid for Today and Tomorrow

Regional Impacts:

 

Today

NB/NS/PEI/NL/Labrador: None

 

Tonight

NS/NB/PEI/NL/Labrador: None

 

Wednesday

NB/NS/PEI/NL: None

Labrador: A chance of thundershowers  

 

Convective Discussion:

 

A ridge of high pressure will continue to move south of Nova Scotia today and Wednesday. For Labrador on Wednesday, a frontal trough will move across the region giving a risk of non-severe convective showers.

 

Thunderstorm outlook for today:

 

Thunderstorm outlook for tonight:

 

Thunderstorm outlook for Wednesday:

 

Convective Outlook Valid for Today and Tomorrow

Regional Impacts:

 

Today

NB/NS/PEI/NL/Labrador: None

 

Tonight

NS/NB/PEI/NL/Labrador: None

 

Tuesday

NB/NS/PEI/NL/Labrador: None

 

Convective Discussion:

 

A ridge of high pressure will move into the region as a weakening low departs Newfoundland.  Stable and dry artic air associated with the ridge will inhibit any potential convection. Non convective showers are expected over Labrador on Tuesday associated with a warm front.

Thunderstorm outlook for today:

 

Thunderstorm outlook for tonight:

 

 

Thunderstorm outlook for Tuesday: