A pleasant start to September The Maritimes saw classic late summer conditions for Tuesday. The region has had a good amount of sunshine with some fair-weather clouds developing during the day. A few pop-up showers are set to end in the evening followed by clearing skies. The temperatures during the day have been mild and bang on average for the start of September. The nights have a crisp feel as clear conditions and low humidity allow for temperatures to fall into the single digits and low-teens. Similar conditions can be expected in the region for Wednesday. Pattern flip and expected timing A big change comes at the end of the week as a low-pressure system moving through Ontario and Quebec approaches the Maritimes. This system will be slow moving in and through the region. A building ridge in the jet stream in western Canada forces a deep trough in the east. The setup will act to trap the incoming system, allowing it to linger like a car tire spinning in a rut in the road. Because the system is stalling, Maritimers can expect a prolonged period of wet weather to develop across the region. Thursday afternoon and evening may bring increasing cloudiness, with the initial leading edge of the rain reaching westernmost communities first. Thursday night and Friday should bring widespread rain, drizzle, and fog across the Maritimes. Saturday will bring damp conditions with lingering rain and showers, meaning the long weekend is likely off to a soggy start. The slow-moving nature of the system does make it difficult to pinpoint when exactly it will be completely clear the region. Some long-range guidance holds a chance of showers into Sunday, while others have us transitioning to a mix of sun and cloud on that day. I expect to have more certainty on that towards the end of the week. Rain potential There is also quite a bit of variance in indicated rainfall totals. Unless the system speeds up and the rain clears quicker, I’d ballpark it as having the potential to produce a widespread 20-to-50 mm with possible areas of 50-to-100 mm. Heavier rain is more likely for eastern New Brunswick, Prince Edward Island, and eastern Nova Scotia. Maritimers may wish to take some time and check property drainage to make sure it is free of any late summer debris. Keep on top of the forecast this week in case you want to adjust travel or plans around the rain.
