Regional Impacts
Today
NL: Slight chance of a thundershower over eastern regions early this afternoon giving heavy downpours.
NB/NS/PEI/LAB : None
Tonight
None
Tomorrow
LAB : Risk of a thundershower over western regions in the evening giving small hail and locally heavy downpours.
NB/NS/PEI/NL : None
Convective Discussion
A low pressure system exits east of Newfoundland this morning and from the 12Z St. John’s sounding, there is some instability from 850 to 500 mb so a slight risk of an embedded thundershower remains for early afternoon near the low centre where there is expected to be sufficient lift to break the cap. Otherwise, a ridge of high pressure over Hudson Bay will continue southeastward towards Atlantic Canada, limiting convection and ushering a more moderately cooler and drier air mass. Only a few isolated showers are expected in the northerly onshore flow off the Gulf of St. Lawrence this afternoon. A weak trough will affect eastern Labrador tonight but no convection is expected with that feature.
For tomorrow, the ridge progresses further east into the Maritimes. The weak trough will affect eastern Newfoundland, but again not expecting convection with this feature. A weak trough north of the ridge will aid in triggering thunderstorms over western Labrador late in the afternoon and evening. MLCAPE may reach 500 J/kg but 0-6km shear is fairly weak at 10 to 20kt, so only expecting multicell type storms with brief wind gusts, small hail and locally heavy downpours.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
