Risk Assessment
Assessing Natural Disaster Risk
Nova Scotia has been known to experience the following events:
- hurricanes
- floods
- storm surges
- heat waves
- forest fires
- winter storms
Storms
Storms frequently pass close to the Atlantic coast of Nova Scotia and cross the southern part of Newfoundland, producing highly changeable and generally stormy weather. Without doubt, this region has more storms over the year than any other region of Canada. Pictou County, on Nova Scotia's North Shore is sometimes by-passed by these Atlantic systems.
Packing a variety of weather conditions from hurricane-force winds to heavy precipitation, systems can pass rapidly through or stall and batter the region for days. On occasion, the winds associated with these nor'easters, as they are called, exceed 150 km/h, and peak wave heights can be as high as 14m. At high tide, these winds can cause storm surges of more than a metre. Other conditions associated with these storms include freezing spray, reduced visibility in snow, rain, or fog, and numbing wind chills, especially in the storm's wake.
In late summer and fall the remnants of a hurricane or tropical storm are felt at least once a year in Nova Scotia.
Other severe weather phenomena include ice storms and blizzards. Each year one or two 25-cm snowfalls occur in Nova Scotia and newspaper headlines across Canada announce another paralyzing Atlantic snowstorm. When combined with strong winds, they cause enormous inconvenience and, at times, property damage and loss of life.
Low risk of lightning strike
On the other hand, Nova Scotia is not known for spectacular displays of thunder and lightning. Thunderstorms occur on about 10 days of the year. Tornadoes have been recorded but are rare. One such tornado, accompanied by heavy hail and lightning, struck White Point Beach near Liverpool on January 30, 1954, but most weather watchers consider it a freakish event. Reports of waterspouts over near shore waters are received yearly.
More information is available from the Provincial Emergency Measures Office . Details on past emergencies recorded by the EMO are:
- Floods
- Hurricane Juan
- February '04 Blizzard
Winds
Winds blow predominantly from the south or southwest in the summer with an average speed of about 10 to 15 km/h. In the coldest months the predominant direction is from the west and northwest with an average speed of 22 km/h.
The wind at any given location is often quite different from the wind conditions which prevail even a short distance away. The variation that occurs in both wind direction and speed results from the characteristics of natural and man-made obstructions, topography, and surface cover. Along the coast, an onshore sea breeze circulation often sets up, particularly during a warm, sunny afternoon in the spring or early summer.
Source: Atlantic Climate Centre
Impact of Climate Change
The Province of Nova Scotia accepts that climate change is real and is taking concrete steps to proactively manage risk, mitigate threats and prevent negative impacts with well-informed future development plans.
Impacts include:
- Rising ocean temperatures: increased hurricane risk (warmer waters allow tropical storms to maintain force further and further north), alteration in predominant fish species, changing marine habitat
- Rising sea level projections 1 metre: direct impact on Nova Scotia coastline and coastal communities, flooding of dykes and loss of land, changes in water quality through salt-water intrusion
- Rising C02 levels: direct impact on forestry - changing tree species viability, altered growth rates, increased risk of pests/disease, changes to soil/nutrients with potential to alter ability for re-growth.