Thunderstorm Outlook for Today
..Severe thunderstorm watch is in effect most of western New Brunswick .. Very dangerous thunderstorms are expected.
Scattered thunderstorms, some severe have the potential to produce heavy downpours, damaging winds, large hail and frequent lightning. There is a slight risk of a tornado.
Regional Impacts
New Brunswick: Initially western portions of the province will be affected by large clusters of thunderstorms advancing over the region from Maine. The threat of severe conditions is initially over central and northern portions of the province, but this area will likely spread east towards late afternoon and evening. At this point, the main threat is for heavy downpours with localised 25mm, wind gusts in the 70 to 90 km/h range and hail of 2 cm or more. There are indications that the environment in which stronger and longer lasting storms could produce a small tornado
Convective Discussion
This morning’s upper air data is showing a large upper trough advancing over the Great Lakes while an upper ridge is about to leave the Atlantic provinces. Between these two features a strong upper jet of 130 knots extends from the central Great Lakes to Labrador. Cold unstable air has reached western Quebec, and the low level thermal ridge and moisture axis now extends from the mid-Atlantic coast to the Notre Dame mountains and the lower St. Lawrence valley. At the surface, the frontal boundary extends from southeast Labrador to southern Quebec and then western NY. The front is expected to move across the Maritimes tonight with the wind finally shifting to north over NS Monday morning.
Scattered thunderstorms will form and become organised in bands during the afternoon, but the bands will be mostly parallel to the flow. But as a strong low level jet continues to inject moisture and temperatures reaches their maximum these clusters/bands will become stronger and persist long enough to become multi-cells which at that point will follow and eastward motion. With temperature/dewpoint of 30,18 CAPE values quickly jump to 1000 to 1500 J/Kg of energy which would be enough to push CB’s tops in the 10-15 km range. Some of the multi-cells storms could produce a tornado over areas near the international boarder in Madawaska county, the hodograph from Caribou is indicating some curvature in the low level winds, and the helicity values are expected to become sufficient. Further south, the strong storms will be producing very heavy rainfall of more than 25 mm, and potentially some large hail.
Thunderstorm Outlook for Day 2
No convection expected
