Convective Outlook valid for Today, and Tomorrow

Thunderstorm Outlook for Today, JUNE 2^nd.

 

A few isolated non-severe thunderstorms are possible offshore of Newfoundland, wrapping around the low centre near the Avalon today.

 

 

Regional Impacts

Lightning will be the only expected hazard from a cell that may pop-up in the Newfoundland marine region.

 

Convective Discussion

As previously mentioned, the Avalon low may spark a cell in the wrapping warm sector today. Elsewhere across the Maritimes there is strong capping at 700mb and above with a ridge building in from the west. Some low-level/mid-level cloud may develop along the moisture tongue across southern NS this afternoon. No thunderstorms are forecast due to this stability profile.

 

 

Thunderstorm Outlook for Day 2, JUNE 3^rd.

 

No thunderstorms expected in Atlantic Canada as the thermal ridge continues to increase stability in the region.

 

 

Convective Outlook Valid for Today and Tomorrow

Thunderstorm Outlook for Today

No thunderstorms expected.

 

Regional Impacts

None

 

Convective Discussion

A couple of troughs extend westward from a low located east of NF, fairly cool with extensive cloud cover and spotty rain/drizzle over the eastern half of the Atlantic provinces. To the west, a frontal wave extends from James Bay to southern New England. Elevated convection with tops above 10 km is associated with this feature but it remain west of the region.

 

Thunderstorm Outlook for Day 2

No thunderstorms expected.

 

Convective Outlook Valid for Today and Tomorrow

Thunderstorm Outlook for Today

 

No thunderstorms expected.

 

Regional Impacts

None.

 

Convective Discussion

The upper air pattern this morning shows two lows, one over northern Ontario and another one east of Newfoundland. In between, a ridge stretches from the Appalachians to James Bay. The airmass instability will produce fair weather cumulus over the Maritimes, and for Newfoundland the cloud cover will be more extensive giving occasional rain or drizzle.

Very little change is expected with these features during the next several days, although the ridge will attempt to build with limited success over western Quebec/Maritimes.

 

 

Thunderstorm Outlook for Wednesday

 

No thunderstorms expected.

 

Convective Outlook Valid for Today and Tomorrow

Thunderstorm Outlook for Day 1

 

Regional Impacts

Slight risk of a non-severe thunderstorm over eastern NS this afternoon, and western NF.

 

Convective Discussion

This morning upper air patterns shows an upper low over Labrador giving extensive cloud cover, also

An upper ridge extends north-south through Ontario to the southeastern US. The airmass between these two features is somewhat unstable, and this instability is found in the mid-levels. Large bands of alto-cumulus extend from southern NF to NS to PEI and then NB, and are producing scattered showers. Clear air prevails over western NS as the 500mb heights increase ahead of the upper ridge.

 

Forecast guidance is suggesting limited instability this afternoon over eastern NS and western NF, but the limiting factor will be the lack of bright sunshine over NS, and the relatively cool temperatures and dry air over NF. For this reason towering cumulus is mostly expected and the likelihood of deeper convection and the chance of any lightning is rather small.

 

 

Thunderstorm Outlook for Tuesday

No thunderstorms expected.

 

 

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Information on Threat Relationships

 

 

Threat	Rainfall Amount	Wind Gusts	Hail Diameter	Tornado Probability
Minor	< 25 mm	< 70 km/h	< 2 cm	Unlikely
Moderate	25 – 50 mm	70 –89 km/h	2 – 4 cm	Low
Severe	50– 100 mm	90– 119 km/h	4 – 6 cm	Moderate
Extreme	100 mm or more	120 km/h or greater	6.0 cm or greater	High
Risk of Thunderstorms: Thunderstorms that develop in this area will be less organized and will not likely meet warning criteria. Severe Thunderstorm Watches will not likely be required.
Slight Risk of Severe Thunderstorms: There is a low probability that weakly organized thunderstorms will develop, these thunderstorms may reach warning criteria. Severe Thunderstorm Watches may be required
Moderate Risk of Severe Thunderstorms: There is a moderate probability that organized thunderstorms will develop, thunderstorms are likely to reach warning criteria. Severe Thunderstorm Watches will likely be issued.
High Risk of Severe Thunderstorms: There is a high probability that well organized thunderstorms will develop, these thunderstorms are likely to meet or exceed warning criteria. Severe Thunderstorms Watches will be issued.

 

Convective Outlook Valid for Today and Tomorrow

Thunderstorm Outlook for Today

 

No thunderstorms expected.

 

Regional Impacts

None.

 

Convective Discussion

The upper air pattern this morning shows two lows, one over northern Ontario and another one east of Newfoundland. In between, a ridge stretches from the Appalachians to James Bay. The airmass instability will produce fair weather cumulus over the Maritimes, and for Newfoundland the cloud cover will be more extensive giving occasional rain or drizzle.

Very little change is expected with these features during the next several days, although the ridge will attempt to build with limited success over western Quebec/Maritimes.

 

 

Thunderstorm Outlook for Wednesday

 

No thunderstorms expected.