Convective Outlook Valid for Today and Tomorrow

Regional Impacts

For Labrador today… Isolated thunderstorms giving 15-20mm locally.

NB, PEI and NS today… Low probability of near severe thunderstorms.

 

Convective Discussion

 

There is a low probability that severe or near severe thunderstorms could develop today over the gulf waters and Northumberland Straight. The dynamics are good with plenty of deep shear and weak convergence along a surface trough. It may be a struggle to break through a stable layer above 700mb until later today when it weakens however daytime heating will also be weakening. For now no severe thunderstorm alerts are expected however should longer lived cells develop they may be issued. The warmer waters this time of year may also help to feed the thunderstorms and should they develop could pose a risk to marine waters.

 

 

Thunderstorm Outlook for Day 1

 

 

Thunderstorm Outlook for Day 2

 

 

Mel Lemmon

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

New Brunswick…Isolated thunderstorms giving locally heavy downpours.

PEI… Chance of isolated thunderstorms late today.

Nova Scotia… A few thunderstorms are expected tonight with locally heavy downpours.

 

Convective Discussion

Despite the cloudiness, favourable dynamics and high moisture are expected to keep thunderstorms progressing though the day in NB and into NS and PEI this evening and tonight. Locally heavy downpours, exceeding 25mm are possible for some areas today and tonight.

 

Tomorrow the upper level jet and increasing wind shear may offset the weaker instability especially over the warmer Gulf and Northumberland Straight waters where there is a chance of thunderstorms.

 

Thunderstorm Outlook for Day 1

 

 

 

Thunderstorm Outlook for Day 2

 

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

Today.. No thunderstorms expected

Tomorrow.. Isolated thunderstorms with locally heavy downpours.

 

Convective Discussion

 

Not much expected today however the dynamics will improve tomorrow as the upper ridge moves away ahead of the approaching cold front. With respect to the moisture we are looking at high precipitable water values and high surface moisture. Vertical velocity could be somewhat limited but most unstable capes could be in the 500-1000 J/kg range, with low level shear above 30 knots some longer lived cells could be a concern, possible producing gusty winds and heavy downpours with local amounts exceeding 25mm/hr.

 

Thunderstorm Outlook for Day 1

 

 

Thunderstorm Outlook for Day 2

 

Convective Outlook for Weekend of Aug 28-29th

Thunderstorm Outlook for TODAY – Saturday, August 28, 2021

 

Regional Impacts

None expected at this time.

 

Convective Discussion

A strong ridge is building in from the west today, and with it is increasing atmospheric stability. Additionally, a northerly flow last night over much of the region dried out the muggy airmass. The cold front is exiting Newfoundland’s marine waters this afternoon, and there are no other forcings at play today.

 

 

 

Thunderstorm Outlook for TOMORROW – Sunday, August 29, 2021

 

Regional Impacts

None forecast.

 

Convective Discussion

Ridge still keeping atmosphere stable and dry in lower and mid levels. Invading high cloud also a deterrent.

 

 

*Forecaster: TIRONE

 

end/ASPC

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

Maritimes:  None today and Saturday.

NFLD/Labrador: A risk of thundershowers this afternoon and evening over central/eastern Newfoundland and southern Labrador. None on Saturday.

 

Convective Discussion

 

Just a chance of embedded thundershowers in Newfoundland today. Over southern Labrador, a few surface based thundershowers are possible this afternoon but the shear is very low so they will be short lived.

 

Thunderstorm Outlook for Day 1