Regional Impacts
Today:
Lab: Risk of a thundershower giving moderate wind gusts and rainfall rates.
NL: Risk of a thundershower giving moderate wind and rainfall rates, along the southern coasts.
NS: Risk of a thundershower inland.
NB/PEI: NIL.
Tonight:
Lab: Risk of a thundershower giving moderate wind gusts and rainfall rates.
NS/NB/PEI/NL: NIL.
Tomorrow:
Lab: Risk of isolated thundershowers giving moderate wind gusts and heavy rainfall.
NS/NB/PEI/NL: NIL.
Convective Discussion
The low-pressure system from yesterday is currently located to the southeast of Nova Scotia. This system is still giving embedded showers and thundershowers with isolated cells giving rainfall rates near 25 mm/hr. As this system progresses, model guidance is indicating that a lot of the forcing will diminish throughout the day. However, there is a cool trough that is forecast to move through the Maritimes, which will mainly act as a trigger for isolated thundershowers over mainland Nova Scotia; predominant areas of concern would be the higher terrain. Over Labrador, there is a decaying ridge of high pressure, and looking at satellite imagery, there is a clearing of mid to upper-level cloud along with a burning off of mist throughout much of the region. CAPE values are rising to near 1,000 J/kg because of this clearing trend. Daytime heating will act as a trigger and initiate some isolated thundershowers.
Tonight into tomorrow, a frontal system will approach Labrador from Northern Quebec today and affect Labrador tonight into tomorrow. There are some timings issues for this frontal system as it approaches, as such hazards are on the lower side. If the system progresses slower and maintains intensity, then tonight there is less confidence in thundershowers tonight and hazards could be more intense for the tomorrow period. Current guidance is giving an early afternoon of approximately 1,500 J/kg of Mixed Layer CAPE (MLCAPE) with shear values remaining around 15KT. If this system moves slower than it will be more likely that the jets will move through at a more effective timing, allowing shear to increase, which would lead to better organization of convection.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
Forecaster: Lambert