Backgrounder

Summary of the 2012 Tropical Cyclone Season

In 2012 the Canadian Hurricane Centre (CHC) issued 64 hurricane information bulletins on four tropical cyclones.

The three main events for the season were:

• Hurricane Leslie which struck Newfoundland as a post-tropical storm on September 11th;
• Hurricane Rafael which raced across the southern fringe of the Grand Banks on October 18th; and
• Hurricane Sandy which had far-reaching influence over southern Ontario and other parts of Eastern Canada on October 29th and 30th.

Former Hurricane Leslie struck Newfoundland as a post-tropical storm causing minor to moderate wind damage over the eastern peninsulas of the island. Hurricane Sandy resulted in Southern Ontario and other parts of Eastern Canada experiencing moderate to severe wind and wave impacts. Offshore events included Post-Tropical Storm Chris along the southeastern Grand Banks on June 22nd, and Post-Tropical Storm Rafael running across the southern fringe of the Grand Banks on October 18th.

Below is a summary of the three primary events of tropical origin affecting Canada in 2012. There was one additional unnamed cyclone which tracked over the Grand Banks on July 25th. As a precaution, gale-force wind warnings were issued for a small portion of the marine forecast district in coordination with the CHC.

Hurricane Sandy

Sandy formed in the southern Caribbean Sea from a significant area of clouds on October 22nd. Over the next two days the storm moved northward and became a hurricane as it approached eastern Jamaica. The post-tropical storm tracked into Pennsylvania on October 30th then dissipated on the 31st, causing damage over a large portion of the Eastern Seaboard of the United States in and around New Jersey. The circulation extended well into Eastern Canada and the Great Lakes. High winds gusted from the north and northeast over southern Quebec and Ontario while warm southeast winds blew into Atlantic Canada. There were high waves and storm surge over Lake Huron where the wind blew down the length of the lake. Waves of five to seven metres were measured in the southern end of the lake.

Rainfall was not a significant issue in Canada. The greatest measured amount was 55 mm in Charlevoix, Quebec. Waves approaching the south shore of Nova Scotia were in the range of five to eight metres, resulting in elevated water levels up to 60 cm along parts of the Atlantic coast in western Nova Scotia.

High wind gusts downed tree limbs and whole trees leading to numerous power outages across southern Ontario. Sandy was to blame for two fatalities in Canada -- one in Toronto when a large sign was blown down and struck a pedestrian. The second occurred in Sarnia, Ontario, when a hydroelectric worker was electrocuted during the post-storm cleanup. The Sarnia area was hit particularly hard as a result of strong north winds off Lake Huron in addition to storm surge and heavy surf. There were a number of reports of trees and poles falling on vehicles and homes, with an estimated $10 million in private property damage in Sarnia alone. Fierce winds and record-high waves disrupted cargo ship travel through Lake St. Clair and the adjacent waterways connecting Lake Erie and Lake Huron.

Hurricane Leslie

Leslie formed from a disturbance in the deep tropical Atlantic in early September and travelled far northeast of the Caribbean Islands. On September 11th, the tropical storm and front merged and tracked into eastern Newfoundland. The official status of Leslie at landfall was 'post-tropical' with maximum sustained winds of 120 km/h. The landfall of the very broad centre of the hurricane was over the southern tip of the Burin Peninsula.

Although not directly related to Leslie, a stalled front over Nova Scotia caused serious flooding with rainfall rates of up to 25 mm/h, causing flash-type flooding around Truro, Stewiacke and Shubenacadie. The greatest total rainfall from the Leslie-stalled front was 165 mm at Shubenacadie, Nova Scotia.

Eastern Newfoundland experienced wind gusts up to 137 km/h at a very-exposed station on the southern Avalon Peninsula. Storm surge was not an issue during Leslie's landfall in Newfoundland. Noteworthy impacts observed include uprooted trees, snapped power poles, damaged roofing and building cladding, broken signage, toppled fences and overturned trucks. Some flooding occurred over western Newfoundland, resulting in undermined roadways, low-land inundation and some stream overflows. Coastal impacts seemed to be related to over-wash and wave-breaking causing minor damage to breakwaters and small structures.

Hurricane Rafael

Rafael formed in the eastern Caribbean on October 12th and moved slowly northward, attaining hurricane status late on the 15th. On October 18th, the hurricane-strength post tropical storm crossed the southern Grand Banks off Newfoundland.

Large waves crashed along the southern coast of the Avalon Peninsula of Newfoundland, four to seven metres high with a 16-second period between waves measured 35 km off the coast. An elevated water level was also witnessed in St. John's Harbour and Grace Harbour, likely from the rapid-tide effect. Cape Race measured some moderate rainfall for a brief period, amounting to 6 mm. Waves were estimated to have been above 10 metres offshore, to the right of Rafael's track.

The more significant impacts were large waves and run-up along some southern coastline communities of Newfoundland. In Trepassey, about 110 km southwest of St. John's, heavy surf tore apart a section of a breakwater connecting two parts of the community. An additional 500-metre portion of coastal roadway suffered heavy pavement damage. More than $1 million in damages was estimated to have occurred in the area as a result of the far-reaching wave impacts.