Thunderstorm Outlook for Day 1- July 19th, 2021
Regional Impacts
Nova Scotia and Prince Edward Island…Isolated risk today and this evening. Locally heavy downpours and gusty winds are possible.
New Brunswick…Isolated risk mainly for central regions with heavy downpours possible today and this evening.
Labrador…Isolated risk for southern regions near this afternoon and evening.
Maritime waters…Isolated thunderstorms continue today and overnight, possibly reaching southern Newfoundland early tomorrow morning.
Convective Discussion
A surface trough lies to the west extending from southern Labrador toward southern Quebec and into the New England. The main threat of organized convection remains closer to the trough north of the St. Lawrence River and extended northeast towards extreme southern Labrador today where heavy downpours and small hail is possible. The Maritimes remain in a moist southwesterly flow today ahead of this trough. Precipitation moved through the region yesterday evening and is now moving into southern Newfoundland today. Isolated thundershowers continue this morning south of Nova Scotia and may make their way inland along the Atlantic coast of Nova Scotia today bringing heavy downpours. Although most of the Maritimes remains cloudy this morning, some scattering of the cloud mainly over the Annapolis Valley and northern Nova Scotia could help the area reach their convective temperature. Dew points this morning are near 20C. There is also the aid of an 850mb low-level jet, weak 0-6km shear of near 20 kts, some cooling in the upper levels, and precipitable water values near 40 mm. Thunderstorms should be short-lived but would likely produce heavy downpours that will drift to the northeast into eastern Prince Edward Island or western Cape Breton this evening.
Thunderstorm Outlook for Day 2- July 20th, 2021
This trough today will continue to slide further east tomorrow. Some enhanced risk is possible over much of New Brunswick, Nova Scotia and Prince Edward Island.
