Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

Today: none.

 

Tonight: none.

 

Monday: isolated embedded thundershowers possible for a portion of mainland Nova Scotia.

 

Convective Discussion

 

An upper level low pressure system will continue to churn southwest of NS today, and will gradually shift northeastward on Monday. There have been some isolated embedded and elevated thundershowers in the plume of moisture associated with the thermal thickness ridge ahead of the upper low which will likely continue today and tonight over marine waters south and west of NS. This same feature will give just a slight risk of a thundershower over portions of mainland Nova Scotia on Monday as the upper low gets closer to the province. With or without the thunder there will be localized heavy rainfall amounts for some regions of western mainland NS. OTWZ nil sig wx is expected in the region.

 

Thunderstorm Outlook for Sunday

 

Thunderstorm Outlook for Sunday night

 

Thunderstorm Outlook for Monday

 

Jeremy

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

Today

 

None.

 

Tonight and Sunday

 

Isolated elevated thundershowers for waters south of NS.

 

Convective Discussion

 

Isolated embedded thundershowers are possible for some waters south of NS tonight and most of Sunday in vicinity of an upper level low pressure system spinning southwest of the marine district. OTWZ nil sig wx expected.

 

Thunderstorm Outlook for Day 1

 

Thunderstorm Outlook for tonight

 

Thunderstorm Outlook for Sunday

 

Jeremy

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