Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

NS/NB/PEI/NFLD: None

Labrador:  A risk for most regions and a chance of gusty winds and hail southeast.

 

Convective Discussion

 

A low pressure system will track across Labrador today. Ahead of the low, daytime heating will allow temperatures to reach 27 degrees. Modifying the upstream sounding at Sept-Iles yields precipital water of 25- 30 mm, cape of 1000 J/kg and unidirectional shear of 30 kts. Additionally the freezing level is fairly low at 9,000 feet.  An upper level jet will approach this afternoon and southeastern Labrador will be in a favourable area of enhanced lift (left exit). The low freezing levels and decent cape above -10 C will support hail growth. The dry mid levels will support possible wind gusts.

 

Thunderstorm Outlook for Day 1

 

 

Thunderstorm Outlook for Day 2

 

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

Risk of  thunderstorms over Northern and Western NB this afternoon, main threat is gusty winds and brief downpours.

Some thunderstorm activity is expected over central Quebec this afternoon and evening, some of these storms may propagate to western Labrador late evening and after midnight

Convective Discussion

This morning, an upper ridge with stable dry conditions prevails over NF, while a cold trough extends from an upper low south of James Bay to southern Quebec. The area with the highest potential for convection is central and southern Quebec and northern Maine. Convective initiation should be fairly easy to attain given the buoyancy of this airmass. Using the most recent Maniwaki sounding, mean layer energy should easily reach 750-1000 J/kg - and with deep layer shear values of about 25kt – this will be adequate to sustain more robust isolated storm cells. Behind the remnants of Isaias, there is a marked drop in moisture content, so the main threat with these storms would be moderate to strong wind gusts.

Thunderstorm Outlook for Day 1

 

Thunderstorm Outlook for Day 2

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

Chance of an afternoon thunderstorm – producing brief downpour and moderate wind gusts - over southern NF.

Convective Discussion

Very moist airmass prevails over NF this morning with a fair amount of potential energy, however mid-level lapse rate continue to be unfavorable for the development of deep convection. The area to focus would be over the southern third of the island where sunshine could help boost surface temperatures to values required for convective initiation, at this point the likelihood remains very low. Having said that, the upper jet (100+kt) may be too strong, shredding any developing towers. Elsewhere across the Atlantic provinces, fair conditions are expected under an upper ridge.

Thunderstorm Outlook for Day 1

Thunderstorm Outlook for Day 2

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

Scattered thunderstorms over central northern and western New Brunswick could produce brief heavy showers and strong wind gusts.

 

Convective Discussion

An approaching cold front and trough currently over southern Quebec will trigger a few thunderstorms this afternoon. Ahead of the front, strong southwesterly flow at all levels will maintain very moist conditions. Low level destabilization during the afternoon will likely lead to some of the storms approaching severe limits – mainly west of our area of responsibility -  however mid-level lapse rates will not be the best over NB.

 

 

Thunderstorm Outlook for Day 1

 

 

Thunderstorm Outlook for Day 2

Convective Outlook Valid for Today and Tomorrow

Regional Impacts

 

NS/NB/PEI/NFLD: None

Labrador:  A risk for western regions with a chance of gusty winds and hail.

 

Convective Discussion

 

A low pressure system will approach western Labrador today. Ahead of the low, daytime heating will allow temperatures to approach 28 degrees. Modifying the upstream sounding at La Grande yields precipital water near 30 mm, cape of 600 J/kg and unidirectional shear of 40 kts. Additionally the freezing level is fairly low at 10,000 feet.  An upper level jet will approach later this afternoon but western Labrador does not look to be in a favourable area of enhanced lift. The low freezing levels and decent cape above -10 C will support hail growth. The dry mid levels will support possible wind gusts.

 

Thunderstorm Outlook for Day 1

 

 

Thunderstorm Outlook for Day 2