Convective Outlook Valid for Today, Friday and Saturday

Regional Impacts

 

Today:

NL: Isolated non-severe thunderstorms possible for southern Newfoundland today with locally heavy downpours and small hail.

NS/NB: Isolated non-severe thunderstorms possible for the valley and northern NS.

 

Tonight:

None over land.

 

Friday:

NS: Isolated non-severe thunderstorms are possible.

 

Saturday:

Isolated non-severe thunderstorms for interior NS and NB.

 

 

Convective Discussion

 

A blocked upper low continues to affect the Maritimes today, keeping the area cool and unstable. Most areas are under low cloud or fog this morning with showers ongoing over New Brunswick, northern Newfoundland and southern Labrador. The greatest chance for some clearing this afternoon will be in central to southern Newfoundland, Nova Scotia and southern New Brunswick where day time high temperatures will trigger some showers. Smoke aloft may keep temperatures a bit cooler and a warm nose evident on the 12Z Shearwater sounding between 700 and 500 mb may prevent much lift beyond 500mb. Although there is decent moisture, the shear is quite weak, so the main would be moderate downpours. Interior Newfoundland has a bit more favourable dynamics with MUCAPE of 500 J/kg but smoke aloft is an issue for reaching expected daytime temperatures as well. Should convection develop, with freezing levels around 6000ft, some small hail is possible.

 

Some embedded thunderstorms south of the Avalon Peninsula this morning should continue to weaken in the next few hours.

 

For Friday, a low pressure system is expected to cross the southeastern Maritimes marine district and southeast of Newfoundland by Friday night. Embedded thunderstorms are possible near the low centre. Where cloud clears in the afternoon over NS, sea-breeze convergence may trigger convection along the spine of NS. Some incoming smoke from wildfires west of the region may prohibit expected daytime temperatures.  There is a similar but possibly more widespread chance of convection for the Maritimes on Saturday.

 

 

Thunderstorm Outlook for Day 1

 

 

Thunderstorm Outlook for Day 1 – Night

 

 

Thunderstorm Outlook for Day 2

 

 

Thunderstorm Outlook for Day 3

 

 

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

Today:

NS: Isolated non-severe thunderstorms possible in Cumberland county dependent on partial clearing. Better dynamics remain offshore of NS.

 

Tonight:

None over land.

 

Thursday:

NFLD: Thunderstorms are possible across portions of Newfoundland – non-severe in nature.

NS/NB: Isolated non-severe thunderstorms are possible, again in partial clearing.

 

Friday:

NB/NS: Daytime heating can contribute to convection developing across inland areas of the Maritimes. Dynamics are not overly strong, but shear is building.

 

 

Convective Discussion

 

The weather pattern is dominated by a stubborn upper level low centred over NB. This feature has a large cloud shield, and is funneling smoke from QUE back down and around its western side. Isolated thundershowers are possible on Wednesday where a cloud hole may occur allowing for enough daytime heating to cause enhanced lift. The dynamics at play are very weak, but we are cool aloft with a ton of boundary layer moisture. The 12z balloon from Shearwater is saturated up to 550mb. 0-6k shear is very low. However, this is the type of weather feature that tends to form funnel clouds in the fall months. Something to consider in coming days as we gain surface based thermodynamics. Nfld has better ingredients tomorrow. Shear will be 25-30kTs with a weak trigger. CAPE values of 100-200J/kg will be enough to generate excited TCUs. Friday will likely see a greater abundance of cells fire-up across the spine of NS and central NB – instability continues to increase as we remain cold aloft. Smoke activing as CIN in the mid levels will need to be re-assessed with future shifts.

 

 

Thunderstorm Outlook for TODAY

 

Thunderstorm Outlook for TONIGHT

 

Thunderstorm Outlook for THURSDAY

 

Preliminary Thunderstorm Outlook for FRIDAY

 

Forecaster: J. TIRONE

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