Regional Impacts:
Today
Labrador/NB/NS/PEI/Magdalen: A chance of non-severe thundershowers.
NL: Risk of rainfall rates exceeding 25mm/hr
Tonight
Labrador/NL: A chance of non-severe thundershowers.
NB/NS/PE/Magdalen: None.
Wednesday
Labrador/NL: A chance of non-severe thundershowers.
NB/NS/PE/Magdalen: None.
Convective Discussion:
Thunderstorms will continue to develop today ahead of a weak cold front in western most NL and adjacent waters. A narrow ribbon of moderate PWATs of 30-35 mm in conjunction with storm motion following a mean SE wind that is almost perfectly parallel to the coast line will bring a heavy rainfall threat here. MLCAPE is rather modest, at 300-500 J/Kg, however it plays well with bulk shears near 30 kts and orographic enhancements for a localized flash flooding threat.
Elsewhere garden variety storms will develop across Labrador associated with a broad upper trough. This feature will swing into Northern NB later in the afternoon and may provide similar non-severe storms. The same front causing storms in western NL does hang back into eastern PEI/NS, however shears of ~40-50 kts appear too high for the limited instability early in the afternoon. CAPE may become high enough to support isolated storms later in the afternoon hours in this higher shear environment with further surface moisture convergence and additional solar insolation.
Tomorrow the same upper trough will continue to provide enough instability for storms to fire with daytime heating across much of Labrador. East of the Long Range mountains a surface trough will be the focus for some thunderstorms in western NL. ML CAPEs of ~300-500 J/kg will work well with moderate bulk shears of ~35 kts. Further east towards Gander shears look to be too high with the expected CAPE environment to support thunderstorms.
Thunderstorm outlook for today:
Thunderstorm Outlook for Tonight:
Thunderstorm Outlook for Tomorrow:
