Thunderstorm Outlook for Today
Regional Impacts
NB: None
NS: None
PEI: None
NF&Lab: None
Marine waters: Isolated thunderstorms developing tonight over southwestern waters, then spreading northeast.
Convective Discussion
The main features this morning are a 500mb upper low south of New England with a southeasterly upper jet ahead of it as indicated by Yarmouth and Shearwater soundings. At the surface, a frontal boundary extend from the back of the upper low, mid-Atlantic coast of the US, to southern Quebec, and then to Labrador. Several low pressure centres are analysed along the front, but the main centre appears to be just north of the Ottawa Valley where several clusters of lightning strikes are detected . Another area with lightning activity is over the Gulf Stream, southeast of Nantucket. Over time, a push of cold air aloft currently over James Bay will catch up with the frontal band over northern Quebec and Lab, while a new upper low emerges over the Maritimes. This new system will drive a swath of very moist air over all of the Atlantic provinces which will eventually connect with the advancing frontal boundary producing some heavy rain. Isolated thunderstorms will likely occur near the upper low, and along the front.
Thunderstorm Outlook for Friday
Isolated thunderstorms ahead of an upper low over CB and southwestern NF, and along a frontal system advancing over Labrador.
