Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

Central/Eastern NB, Western PEI, and Western NS: Isolated thundershowers, with locally heavy downpours of 10-15 mm possible.

NL: None.

 

Convective Discussion: A ridge of high pressure dominates the Maritimes today and tomorrow. Mixed layer CAPE values of 250 to 500 J/kg in central and eastern NB, extending into western NS, will aid in developing some weak thundershowers along terrain, with locally heavy downpours the main risk. Storms are not expected to be long lived due to a lack of wind shear and upper level support.

 

Thunderstorm Outlook for Day 1

 

 

Thunderstorm Outlook for Day 2

 

 

-Copp

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

Western Labrador… low likelihood of isolated thundershower. Locally heavier downpours possible 10-15mm.

 

Convective Discussion… For the most part today will be relatively quiet with a few isolated thunderstorms developing over western Labrador. The dynamics are not particularly favourable with very little wind shear, and no upper support for long lived thunderstorms. Activity will likely be driven by daytime heating and terrain, with mixed layer CAPE is likely less than 500 J/kg. It is possible that there will be some locally heavier rain and small hail. No Severe weather is expected.

 

 

Thunderstorm Outlook for Day 1

 

 

Thunderstorm Outlook for Day 2

 

 

Lemmon

Convective Outlook Valid for Today and Tomorrow

Today:

NL: isolated non-severe east of NFLD.

NS: small possibility of isolated non-severe thunderstorms over some areas of NS.  Local downpours possible giving up to 10mm.

NB: Isolated non-severe thunderstorms possible over western NB. Local downpours possible giving up to 10 mm. 

PEI: none

 

Tonight:

None.

 

Saturday:

None.

 

 

Convective Discussion

 

Possibility of non-severe thunderstorms over parts of the Maritimes today.  We continue to sit under a cold pool and there is significant cloud cover over the area with highs only reaching 15 to 17C.  The risk will be for areas where clouds clear up a bit this afternoon.  These areas could realize 300 to 400 J/kg which could be enough for small non severe thunderstorms to form.  With energy values so low and no wind shear to speak of, these storms will likely be short lived.  If any cells do form, they will be slow moving so local downpours are possible giving up to 10 mm.   

 

Thunderstorm Outlook for Today

 

 

Thunderstorm Outlook for Tonight

 

 

Thunderstorm Outlook for Sunday

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