Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

 

Maritimes… Scattered showers and thunderstorms developing early, local 20mm rain, small hail and some wind gusts.

NFLD.. Isolated thunderstorms possible southwestern parts of the island.

 

 

Convective Discussion

 

Like yesterday, thunderstorms have broken out early under the upper trough. Convective temperatures are likely around 23 C although with terrain and local convergence in a few areas thunderstorms may break out earlier in some areas. Cape values are near 1000 J/kg but with low shear organised storms are not expected. However given the low freezing levels around 9000 ft and some downdraft potential small hail, with some wind gusts can be expected. Things should settle down tonight as the upper trough pulls away, however tomorrow a second upper trough will move in and stall over the area for a period. Conditions for tomorrow will not likely be quite as unstable however there is still a risk of thunderstorms for some western areas.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

 

Thunderstorm Outlook for Tomorrow

 

 

Mel Lemmon

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

 

Labrador.. Slight chance of isolated thunderstorms.

NFLD.. Slight risk of thunderstorms for central regions.

NS.. Chance of heavy downpours in thunderstorms over central region, local 15 - 25mm or more possible.

PEI.. Chance of isolated thunderstorms.

NB.. Scattered thunderstorms over northern areas, local 20 mm possibly more in clustered thunderstorms. Isolated Thunderstorms south.

 

Convective Discussion

 

An upper trough moving across the region will generate thunderstorms throughout the day across northern NB, and possibly later this afternoon for NS, PEI and NFLD. Dynamics further south, over NS and southern NB are more favourable for severe storms than over northern NB were thunderstorms have already begun, but the updraft strength is likely to be much lower. However, the warm cap aloft will break down as the upper tough approaches and some intense storms are possible, the most likely area begin over central NS, central NFLD has a slightly lower risk of organised convection. Although severe thunderstorms are not expected for NB, we will be monitoring closely for backing building thunderstorms and alerts may be required should the set up happen. Some thunderstorms can be expected to persist overnight and begin fairly early again tomorrow.

 

Thunderstorm Outlook for Today

 

 

 

Thunderstorm Outlook for Tonight

 

 

Thunderstorm Outlook for Tomorrow

 

 

Mel Lemmon

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

Risk of a thunderstorm today across southern LAB.

 

Scattered thunderstorms likely across NB and a portion of Labrador on Monday. Slight risk of a thunderstorm for a portion of NS and PEI.

 

Convective Discussion

Not much on the go today aside from a weak upper trough that might give a thunderstorm or 2 across southernmost Labrador. An upper trough will advance from the Great Lakes region on Monday giving more support for scattered thunderstorms across NB and portions of Labrador. Some small hail, gusty winds and torrential downpours possible in the deeper cells. OTWZ nothing else to talk about.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

 

Jeremy

Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

 

Today

NS/NB/PEI/northern/NL/SErn LAB: Embedded thunderstorms bringing heavy downpours.

 

Tonight

Embedded thunderstorms over the southern marine waters.

 

Sunday

Isolated thunderstorms over the southeastern marine waters.

 

Convective Discussion

 

The centre of Post-Tropical Cyclone Debby is tracking through Anticosti and towards northern Newfoundland this afternoon. A trailing cold front will be weakening as it moves across southern New Brunswick, Nova Scotia and Prince Edward Island today. The main risk of embedded convection is along this front where rainfall rates could reach over 20 mm/h. Southern New Brunswick has already seen near 100 mm total rainfall since yesterday from heavy downpours and enhanced upslope flow as precipitable water of upwards of 50 mm continues to stream northward from the Gulf Stream  There may be some TCUs in showers with a slight risk of a thundershower over western New Brunswick this afternoon if a cap near 700 mb can be breached based on the morning Caribou sounding. Embedded thunderstorms will continue eastward over the southern marine waters tonight and into Sunday.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Sunday

 

 

 

Roberta McArthur

 

 

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