Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

Today:

NS: A slight risk of an embedded thundershower for some regions of Nova Scotia.

 

Tonight:

None.

 

Tuesday:

None.

 

Convective Discussion

 

There is a slight risk of an elevated, embedded thundershower for a portion of NS today in the divergent flow aloft, ahead of an approaching upper level low pressure system. There has been some history of convection with the upper low, but very little lightning has been observed the past 6-10 hours or so. The only threat would be very heavy rainfall amounts in a short period of time. Elsewhere an approaching frontal trough over central Quebec will likely give some afternoon thunderstorms that are expected to remain southwest of the Wabush/Lab City area. OTWZ nil sig wx to talk about.

 

Thunderstorm Outlook for today

 

Thunderstorm Outlook for tonight

 

Thunderstorm Outlook for Tuesday

 

Jeremy

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