Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

 

Today

NB…Embedded thunderstorms bringing heavy downpours.

NS/PEI/NL…None

 

Tonight

NB/NS/PEI…Embedded thunderstorms bringing heavy downpours.

NL/LAB:  None.

 

Saturday

NS: Embedded thunderstorms bringing heavy downpours.

NB/PEI/NL/LAB: None.

 

Convective Discussion

 

Post-Tropical Cyclone Debby is interacting with an upper trough over central Ontario, helping to advect moisture into southern Quebec, New England and into the Maritimes today then towards Newfoundland into Saturday. The axis of heaviest moisture with embedded thunderstorms this morning has been over the St. Lawrence River towards eastern Ontario and south into New York State and along the southern coast of Maine. These areas are expected to move across northwestern New Brunswick and the Gulf of St. Lawrence overnight and into the Bay of Fundy. Pockets of heavy rain should then pull eastward into southern New Brunswick, PEI, NS and Newfoundland on Saturday with a trailing cold front. There may be embedded convection with this rain, enhancing rainfall amounts as precipitable water of 50 to 60 mm moves through the region but with a quite warm 500mb level as well, convection may end up capped. Regardless, heavy downpours are expected.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Saturday

 

 

 

Roberta McArthur

 

 

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts…

 

Today

NB/NS/PEI: None.

Labrador/NL:  Chance of non-severe thunderstorms.

 

Tonight

NB/NS/PEI/NL/Labrador:  None.

 

Friday

NB/NS/PEI: Risk of non-severe embedded thunderstorms.

NL/Labrador: None.

 

Convective Discussion

There is a risk of non-severe thundershowers for portions of eastern Labrador and northern Newfoundland today in the unstable northwest flow in the wake of a low well east of the region. On Friday, embedded non-severe thundershowers are possible over portions of the Maritimes associated with the remnants of Tropical Storm Debby which is moving up the east coast of the United States.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts…

 

Today

NB/NS/PEI/NL: None.

Labrador:  Chance of non-severe thunderstorms.

 

Tonight

NB/NS/PEI/NL/Labrador:  None.

 

Monday

NB/NS/PEI: None.

NL/Labrador: Risk of non-severe thunderstorms.

 

Convective Discussion

There is a risk of non-severe thundershowers for portions of eastern Labrador today and Thursday in the unstable northwest flow in the wake of a low well east of the region. The thundershower risk will extend into northern Newfoundland on Thursday.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

Scattered non-severe thunderstorms today for a portion of NL and southeastern Labrador.

 

Convective Discussion

A fairly large scale cold front is crossing the region today. There have been some scattered thunderstorms ahead of it and this will continue as it moves off to the east northeast. Just some heavy downpours are expected for a portion of NL and southeastern Labrador. There will be a slight risk of a thundershower for southeastern Labrador Wednesday, but such low confidence in seeing that doesn’t even warrant hatching a grey area on the map.

 

OTWZ quiet weather for the next several days, which is a welcome relief for some.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

 

Jeremy

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

 

Today

Risk of a severe thunderstorm this afternoon for central and northeastern NL as well as eastern NS and parts of PEI giving locally torrential downpours. Risk of non severe thunderstorms for central and eastern LAB.

 

Tonight/Tuesday morning

Scattered embedded thunderstorms likely across a good portion of the Maritimes, southwestern NL and southeastern LAB giving locally heavy downpours.

 

Tuesday afternoon/evening

Scattered thunderstorms possible for a good portion of NL as well as southeastern LAB.

 

Convective Discussion

The air mass responsible for several rain-producing severe thunderstorms in NS yesterday is now in place over NL, with a surface trough now entering the island portion of the province to act as the trigger after lunch. PWATs are in the low to mid 40’s (observed at 12Z in YJT), and adjusting for high temps of about 26 gives plenty of mixed-layer CAPE. Expect to see a couple strong to severe thunderstorms giving locally torrential rainfall. Some gusty winds also possible but nothing drastic. At first glance one would expect the same potential across eastern NS and eastern PEI, and it does exist. The only caveat today is lack of a trigger as the MRTMS are in between short wave troughs. It might be tough to get enough forcing to generate good storms today. There is certainly plenty of moisture and decent instability so if there is local areas of surface convergence we could see an isolated severe storm giving intense rainfall. Lastly scattered thunderstorms look likely for a chunk of LAB today as a short wave trough passes through. Gusty winds and locally heavy downpours look likely, as well as small hail owing to the fairly steep low level lapse rates observed out of YYR.

 

A fairly large scale cold front will sweep across the MRTMS tonight and then NL Tuesday bringing some scattered thunderstorms to the region. Locally heavy rainfall seems to be the only concern at this time.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

 

Jeremy