Regional Impacts
NB: scattered strong to severe storms capable of producing strong winds, hail, heavy downpours and a possible funnel cloud or tornado
PEI: isolated to scattered strong storms capable of producing strong winds, hail and heavy downpours
NS: isolated thunderstorms giving heavy downpours
NL: isolated non-severe thunderstorms over western regions
LAB: isolated non-severe thunderstorms over southwestern regions
Convective Discussion
Active weather is expected for most of the Maritimes today and tonight. An upper low pressure system over central Quebec slowly pushes eastward today while a trailing cold front pushes from southern Quebec into New England. The front then moves into New Brunswick this afternoon and into Prince Edward Island and Nova Scotia in the overnight period.
Most of New Brunswick remains in cloud this morning with some showers moving through this morning but some breaks in the clouds are now occurring over eastern regions. Temperatures in central to southern New Brunswick are expected to be in the low 30s and dewpoints near 20C. A cyclonic 250mb jet will track slowly southeast into New Brunswick with a strong southwesterly jet of 35KT at 850 mb. With MUCAPE values around 2000 J/kg and strong southwesterly 0-6km shear of 40KT combined with low level shear (SRH around 100) and upper divergence, storms that develop will be able to be maintained this afternoon and possibly continue into the evening as elevated convection over PEI and Nova Scotia. The main storm motion will initially be supercells with a mean motion of storm to the northeast at 35KT A possible tornado cannot be ruled out, mainly over central to eastern New Brunswick given similar dynamics to yesterday which saw some splitting supercells over northwestern New Brunswick with generally an eastward motion. Supercell composities for this afternoon are indicating values of 2 to 3 with significant tornado parameters of 1 to 2. Towards the late afternoon, squall or bowlines with strong wind gusts will likely be the main storm threat as storms begin to lose energy but elevated convection may continue into the overnight period with heavy rainfall.
Over Newfoundland, a warm frontal features continues to track northward and convection that occurred early this morning will weaken. Isolated convection this afternoon from the trough over central Quebec will move into southwestern Labrador this afternoon and weaken by this evening.
Thunderstorm Outlook for Day 1
Thunderstorm Outlook for Day 1 Night
Thunderstorm Outlook for Day 2
Upper low moves into Labrador for Tuesday where area of southern Labrador will see scattered showers and thundershowers. The cold front over the Maritime waters will continue to weaken but there could be some isolated thundershowers remaining through the Slope waters, Grand Banks and eastern Newfoundland. A warm cap at 700 mb may inhibit surfaced based convection.
