Regional Impacts
Today
LAB: chance of isolated thundershowers over eastern sections giving brief strong wind gusts.
NB: chance of embedded thunderstorms late evening over western sections.
NS/PEI/NL: None
Tonight
NS/NB/PEI: chance of embedded thunderstorms giving heavy rainfall and strong wind gusts.
Tomorrow
NS/NL/LAB: chance of embedded thunderstorms giving heavy rainfall and strong wind gusts.
NB/PEI: None
Convective Discussion
The stalled upper low over Labrador over the last few days is finally starting to track northward and weaken today. There is a weak shortwave currently over central Labrador, moving towards the east, and this is the trigger for thundershowers today. There is potential effective shear of 30-40kt and MLCAPE of 250J/kg, but with low moisture, some cells may organize and provide brief strong wind gusts.
While a ridge dominates the Maritimes and Newfoundland during the day, a low pressure system currently over the Great Lakes will deepen as it tracks towards the Maritimes tonight. Rain ahead with the warm front should reach New Brunswick this evening, while convective showers with the cold front will move across the Gulf of Maine and towards western New Brunswick and Nova Scotia close to midnight. This system is quite active this morning along the warm front, aided by strong dynamical forcing. Overall dynamics and thermodynamics are expected to be reduced as the system reaches the Maritimes. However, there is an increasing 60kt 850mb LLJ tonight ahead of the cold front in Nova Scotia and the southern Maritime waters. This along with possible mid-level cooling aloft may help embedded thunderstorms persist as the front continues eastward overnight, reaching eastern Nova Scotia by mid-morning. Regardless if lightning does persists, strong southerly winds and increasing precipitable water (40-50 mm) will allow for heavy rainfall rates and strong wind gusts with the frontal passage.
For tomorrow, the low centre is expected move from northern New Brunswick towards the northeast, reaching Anticosti by tomorrow evening. The cold front continues to advance, reaching Newfoundland by mid-morning. Embedded thunderstorms are still possible with heavy rain across southern Newfoundland.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
