Risk of downpours and thunderstorm, as maritime weather taps into remnants of Tropical Storm Cindy

A pedestrian shields themselves from rain and wind during a rainfall warning in Halifax on Thursday, January 26, 2023. (Courtesy: THE CANADIAN PRESS/Darren Calabrese)

An almost-tropical level of moisture in the air has now fully enveloped the Maritimes.

Humid air from the subtropical Atlantic continues to circulate from near the Bahamas, up the U.S. eastern seaboard, and directly into the Maritimes. That air cools and lifts as it arrives and so a lot of that moisture condenses out into cloud, showers, drizzle, and fog.

We can keep track of the progress of the subtropical sourced air through high dew point temperatures. Currently they extend all the way up the U.S. eastern seaboard and into Atlantic Canada.

We can keep track of the heavy, moisture filled air by looking at dew point temperatures. When dew point temperatures climb into the high-teens and low-twenties it becomes an uncomfortable level of humid for many.

This week prepare for humidex values that will make it feel into the high twenties and low thirties at times despite most air temperature peaking in the low-to-mid twenties.

Despite modest late June air temperatures the humidity in the air is making it feel into the high twenties and low thirties for many.

We also appear to have tapped into an additional source of moisture. A second band of very humid air has now developed from the remnants of Tropical Storm Cindy that sits to the south of the Bahamas. While it may now be disorganized showers and thunderstorms, it still packs a lot moisture. That second stream moving in now further increases the risk of thunderstorms and downpours within our periods of showers.

A second flow of moisture from the remnants of Tropical Storm Cindy further increases our risk of downpours and thunderstorms.

The high rainfall rates within the thunderstorms and downpours can be hazardous. Driving into one will bring visibility down suddenly and flash flooding/hydroplaning conditions are possible. Environment Canada has issued a special weather statement for the Bay of Fundy coastline of New Brunswick, cautioning on rain totals that could reach or exceed the range of 30 to 50 millimetres through Thursday.

I would also include Nova Scotia in the risk of seeing at least local amounts in that range due to the presence of the downpours and thunderstorms.

The generally humid and damp weather is expected to continue into and through the Canada Day long weekend.