Thunderstorms, wildfire smoke, and tracking tropical storm Ernesto

Tuesday thunderstorms

Scattered showers and thunderstorms will continue to develop across parts of the Maritimes Tuesday afternoon into early evening. The showers and thunderstorms will weaken and end late Tuesday evening towards midnight.

The highest chance of further thunderstorms Tuesday afternoon and evening is in eastern Prince Edward Island and eastern Nova Scotia, including Cape Breton. Isolated showers or thunderstorms are possible in eastern New Brunswick and parts of northern/central Nova Scotia.

The thunderstorms have been producing frequent lightning and downpours. It is possible that some hail could be produced as well. Just after noon on Tuesday, Environment Canada issued a severe thunderstorm watch in Cape Breton.

More thunderstorms are expected to develop in the Maritimes Tuesday afternoon into evening.

Along with thunderstorms Tuesday, the conditions near Cape Breton have allowed for the development of at least one waterspout. While typically weak, if a waterspout does come onshore, it would be considered a tornado.

A waterspout was spotted off the coast of the Cabot Trail in Cape Breton on Aug. 13, 2024. (Source: Bryan McNamara)

Wildfire smoke present

A haze of wildfire smoke is showing on satellite imagery moving into the Maritimes from the northwest.

The source of the smoke is wildfires in northern parts of the Prairies and in the territories. The smoke is located high in the atmosphere and is moving over a ridge in the jet stream centred over Hudson Bay before travelling southward into a trough centred over Atlantic Canada.

Since the smoke is located so high aloft of the Maritimes, no significant impact to air quality in the region is expected.

The flow of wildfire smoke over a ridge centred over Hudson Bay as illustrated on firesmoke.ca

Tropical storm Ernesto

Tropical storm Ernesto is passing through the northeastern Caribbean Islands, impacting Puerto Rico on Tuesday.

Parts of the island chain are experiencing tropical storm-force winds. A storm surge of 30 to 90 cm is possible for eastern Puerto Rico and the U.S. and British Virgin Islands.

The heaviest rain is expected across southeastern Puerto Rico where it could total as much as 150 to 250 mm. For Guadeloupe and Dominica, as well as across the U.S. and British Virgin Islands, rain could total 100 to 150 mm.

The storm is forecast to move north of the British Islands by Wednesday morning, strengthening to a Category 1 hurricane. It is then forecast to continue to move northward, approaching and passing Bermuda as a Category 2 hurricane Saturday morning into Sunday morning.

The forecast cone for Ernesto. It is projected to become a Category 2 hurricane as it approaches Bermuda at the start of the weekend.

The five-day forecast cone issued by the National Hurricane Center currently ends there. Increased uncertainty in the forecast for a storm beyond five days grows to too high a level to be of much use for impact planning beyond that.

Given that the storm is expected to pass Bermuda, continuing northward, this weekend does make it one we have to watch in the Maritimes. It is possible that by Sunday night or Monday the storm comes close enough to impact the region. It is also possible that the storm tracks far enough to the east of the Maritimes to have minimal impact. Monitor for updates on the progress of the storm through the week. I’ll have those daily here at CTV News Atlantic.