Regional Impacts
Today
NB: Scattered thunderstorms developing this afternoon and evening, risk of severe thunderstorms in organized bands/features in the NW. Rainfall rates in excess of 25mm/h, gusts to 80km/h, and hail diameter near 2cm.
NF&LAB: Isolated non-severe thunderstorms in western Labrador, also south coast of the Island.
Tonight
NB: Isolated thunderstorms possible giving mainly heavy downpours.
Saturday
NB: Isolated thunderstorms likely for a good portion of NB giving possible some hail, strong wind gusts and heavy downpours.
LAB: A slight risk of a thundershower over southern portions giving locally heavy downpours.
Convective Discussion
At 12z a surface low was located east of James Bay with a warm front extending eastward to Lake Melville, and a decaying cold front southward to New England. A couple of cold trough are rotating around a 500mb low located over Hudson’s Bay, one of which is linked to the surface frontal boundary. A 85kt cyclonic upper jet stretches from Long island-central Maine-Lower Quebec North Shore. Convection from yesterday has vanished for the most part, some lingering cells are detected north of the St. Lawrence. The cold front will enter the region later in the day and will be the focus for surface-based instability. Convective temperature in the upper 20’s should be reached fairly easily and robust dynamics should lead to some organized convection over northern Maine around the middle of the afternoon. The steering flow will promote propagation of the activity into Madawaska-Victoria and potentially into Carleton county. Surface-based CAPE of 1000-1500 J/kg and deep layer shear values of nearly 50kt indicates a potential for supercell development.
Thunderstorm Outlook for Today
Thunderstorm Outlook for Tonight
Thunderstorm Outlook for Tomorrow
