Nova Scotia·Weather

Erin set to track into the Maritimes on Thursday, bringing risk of flash flooding

CBC meteorologist Ryan Snoddon says Erin will bring heavy rain to some parts of the Maritimes. Gusty winds are on the way too.

The tropical system is set to bring some heavy rain and gusty winds to parts of the Maritimes

Erin continues to struggle today, thanks to strong wind shear. Note the low level centre of the system is exposed, with the whitest clouds and convection displaced well to the south. (Ryan Snoddon/CBC)

Erin, our incoming tropical system, temporarily strengthened into a tropical storm overnight but has been downgraded to a tropical depression strength today due to a strong wind shear.

No matter whether it's a tropical storm or depression, Erin will track into the Maritimes on Thursday with heavy rain and gusty winds as a post-tropical storm.

An incoming cold front will help to funnel tropical moisture northward and into the Maritimes on Thursday, well ahead of Erin. (Ryan Snoddon/CBC)

The track of this storm is obviously the key to the forecast and there are plenty of factors, including the timing of Erin and the timing of an incoming cold front from the west. 

That cold front will bring its own round of rain into the Maritimes on Thursday, before helping to draw in some tropical moisture ahead of Erin and then we'll see the storm itself arrive on Thursday night.

With this storm we'll be seeing the heaviest rainfall to the left of Erin's track and the strongest winds to the right of the track.

The exact track of Erin will be key, with the heaviest rain to the left of the track and the strongest winds to the right. (Ryan Snoddon/CBC)

Some uncertainty remains, however based on the current projections it's looking more like western Nova Scotia, southeastern New Brunswick and P.E.I. will see heaviest rainfall, while eastern Nova Scotia and Cape Breton will see the strongest winds.

This storm forecast remains a tough call for Halifax and central regions of Nova Scotia. Just a slight shift to the west or east, would lead to significant changes in the forecast. As of now, it appears Halifax is at risk to see the heaviest rainfall, however stay tuned for updates over the next 24 hours.

Rainfall

To the left of Erin's track, we'll likely see a widespread area with rainfall amounts in the 40-80 millimetre range, with more than 100 millimetre not out of the question in some localized areas. The heaviest rain will be tracking through on Thursday night, which is when we could see localized pockets of 50 millimetre in just a 12-hour period. Obviously, this amount of rain over such a short period of time will certainly bring the risk for localized flash flooding.

Wind

The strongest winds with these types of storms are found near and to the right of the track. Based on the current track, the strongest winds with gusts 70-90 km/h, are looking set for the Eastern Shore, eastern mainland Nova Scotia and Cape Breton. We could certainly see some power outages and minor tree damage.

Nova Scotia Power will be activating its emergency operations centre on Thursday in advance of the storm. The utility said it will be placing crews around the province and working with staff and contractors to make sure it can respond safely and quickly as needed.

Storm surges

With the current track and expected strength of the system, storm surge doesn't appear to be a big threat at this point. However, we'll see some high surf and pounding waves along the Eastern Shore and Cape Breton, overnight Thursday and into Friday morning.

Be prepared

With localized flooding and power outages certainly possible, now is a good time to make sure you have your home emergency kits ready to go. If not for this storm, then perhaps you might need it for the next one. We are now entering the peak of the Atlantic hurricane season, which continues through the month of September.

Again, with this storm evolving quickly, the forecasts will be changing as well. The latest updated information can be found in my live blog below and I'll of course have another update this evening at 6 p.m. on the television newscast.

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ABOUT THE AUTHOR

Ryan Snoddon

Meteorologist

Ryan Snoddon is CBC's meteorologist in Nova Scotia and New Brunswick.