RA IV/HC-XXXII/Doc. 4.2(5), p. 2
WORLD METEOROLOGICAL ORGANIZATION______
RA IV HURRICANE COMMITTEE
THIRTY – SECOND SESSION
HAMILTON, BERMUDA
8 TO 12 MARCH 2010 / RA IV/HC-XXXII/Doc. 4.2(5)
(4.III.2010)
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ITEM: 4.2
Original: ENGLISH
REPORTS OF HURRICANES, TROPICAL STORMS, TROPICAL
DISTURBANCES AND RELATED FLOODING DURING 2009
2009 Tropical Cyclone Season Summary
(Submitted by the Canadian Hurricane Centre)
1. INTRODUCTION
Two tropical cyclones entered the Canadian Hurricane Centre (CHC) Response Zone (RZ) in 2009. With the arrival of Hurricane Bill during the third week of August, the CHC issued hurricane and tropical storm watches and warnings for both Nova Scotia and Newfoundland. Bill was a tropical storm when it made landfall in southern Newfoundland before heading out to sea. Just one week later, the remnants of Tropical Storm Danny brought heavy rainfall to the same two provinces. The CHC issued a total of 37 information statements about these two tropical systems.
BULLETIN SUMMARIES / 2009 / 2008 / 2007 / 2006 / 2005 / 2004 / 2003 / 2002Hurricane Information Statements
(WOCN3X/7X CWHX) / 37 / 90 / 48 / 93 / 87 / 104 / 113 / 68
Number of Storms Represented by these Bulletins / 2 / 6 / 4 / 5 / 7 / 8 / 8 / 8
2. BILL
On August 15, Bill was a topical depression off the coast of Africa, strengthening to a hurricane several days later. Bill passed to the west of Bermuda as a Category 2 hurricane but far enough away to spare the island significant wind damage. Bill continued on first a northerly and then a northeast trajectory, entering Georges Bank as a Category 1 storm early on August 23rd. By that afternoon it passed within 20 kilometres of Cape Canso, Nova Scotia. Shortly after the midnight hours of the 23rd, Bill weakened to a tropical storm before crossing the Burin and Avalon peninsulas of Newfoundland on its way out to sea, passing north of the Hibernia platform early on August 24th.
2.1 Conditions
Unlike many tropical systems which become absorbed in frontal systems as they enter Atlantic Canada, Bill encountered a moist tropical-like air mass over much of the Maritimes and Newfoundland. Nova Scotia, Prince Edward Island and Newfoundland each had at least one station reporting rainfall amounts of 70 mm. Wind gusts were as high as 93 km/h at Hart Island, N.S. and 131 km/h at Cape Race, N.L. Over the sea, a buoy over LaHave Bank to the southeast of Nova Scotia measured the strongest gust from Bill at 135 km/h.
The sea state was the most notable aspect of Bill. Buoys on the open sea of Canadian waters reported significant wave heights of 10 to 14 metres. The maximum storm surge was measured at Halifax Harbour at just over 0.5 metres, whereas St. Lawrence, at the entrance to Placentia Bay in Newfoundland, reported a surge of 0.9 metres.
Selected Peak Wind Gusts and Rainfall for Hurricane Bill
Sable Island, N.S. / 124 / Lockeport, N.S. / 71.0
Hart Island, N.S. / 93 / Queensport, N.S. / 72.0
St. Paul Island, N.S. / 102 / Alliston, P.E.I. / 66.8
Saint Lawrence, N.L. / 96 / Winterland, N.L. / 63.0
Cape Race, N.L. / 131 / Gander, N.L. / 71.2
2.2 Impacts
In Nova Scotia Bill brought spectacular waves that crashed on shore. In fact, two days before Bill even passed nearby, the swell was recorded at a buoy anchored near the mouth of Halifax Harbour. This same buoy later recorded a maximum wave height of nine metres in the immediate wake of Bill. Pounding surf washed out the causeway at Western Head, N.S., and seaside roads became clogged with seaweed, sand and debris. Stones the size of volleyballs were washed onto the road at Cape Sable Island, N.S.. Onlookers rushed to observe the high surf at Peggy’s Cove and other popular seaside beaches in Nova Scotia, and traffic snarls ensued when the RCMP closed roads leading to these areas. Public safety became a concern when three young men were swept from a rock by a wave at Peggy’s Cove but fortunately were not swept out to sea. Post-storm assessments of the beach areas revealed damage to a few boardwalks and stairs.
In Newfoundland the storm surge was an issue. Two nursing homes and a hospital in Placentia were evacuated. Fortunately however, the surge did not breach the harbour front and only some freshwater flooding was noted. Heavy rainfall caused ponding and minor gravel road erosion. A road was reported washed out at North Harbour on St. Mary’s Bay, N.L.
Several trees were downed in the provincial capitals of Newfoundland and Nova Scotia, and a few branches, twigs and leaves littered roadways throughout both provinces. Power outages affected a peak of 42,000 customers of Nova Scotia Power on Sunday afternoon. Ferry service between Newfoundland and Nova Scotia was disrupted and flight delays and cancellations were noted at Halifax Stanfield International Airport.
2.3 Warnings & Information Statements
Environment Canada’s Newfoundland and Labrador Weather Office in Gander and the Atlantic Storm Prediction Centre in Halifax issued a combined total of 129 public warnings for heavy rain, wind and surge. The offices posted 33 marine warnings for hurricane, storm and gale force winds. The CHC issued 39 tropical storm and hurricane watches plus 23 tropical storm warnings for Nova Scotia and Newfoundland. Hurricane bulletin production began on the morning of the 20th. A total of 30 information Bulletins were subsequently transmitted.
2.4 Coordination and Communications Effort
The weather offices in Halifax and Gander and the CHC responded to well over 300 media requests relating to the storms, 20% of which were given before the CHC began producing messages. The CHC held two media technical briefings on August 21st and held another two over the weekend. About 20 journalists and camera people attended with another 30 to 65 participating via teleconference for each briefing. Some of these briefings were broadcast live. Provincial EMOs were invited to attend and the NS EMO made a statement and answered questions at the Sunday briefing. CBC Radio and News Radio in Halifax provided live coverage of the storm all day Sunday. News World, the Weather Network and CTV also had live segments.
The Weather Preparedness Meteorologists (WPMs) provided daily briefings plus ongoing briefings to Emergency Measures Organizations and the NS Emergency Health Service. A special briefing was held focusing on the Canada Games in Prince Edward Island. Forecasters and WPMs also engaged in several consultations with Fire and Emergency Services Newfoundland. As a result, the town of Placentia declared a state of emergency and evacuated to two seniors residences and their hospital.
The CHC website received more than one million hits over the course of the storm.
3. DANNY
Danny was born and died as a disorganized system. Originating off the coast of Africa, by the time Danny was positioned east of the Bahamas, the storm had taken on tropical storm characteristics. As it tracked toward Nova Scotia, it became increasingly difficult to distinguish as a separate entity by the evening of August 29th. Shortly thereafter, Danny was absorbed into a low pressure centre moving up through the Gulf of Maine. The remnants of Danny enhanced the development of this low. The low pressure centre subsequently tracked through Newfoundland before dying in the mid Atlantic.
3.1 Conditions
Once Danny was incorporated into the low over the Gulf of Maine, the combined system produced heavy rain as it tracked through the Bay of Fundy and then over Prince Edward Island. A swath of 60 to 110 mm fell over much of southern New Brunswick, Nova Scotia and Prince Edward Island with extremes of 110 to 130 mm reported along the Fundy coast of New Brunswick. A swath through the middle of Newfoundland received 40 to 60 mm of rain.
Over the Maritimes, gusts in excess of 90 km/h were reported in several localities in Nova Scotia. Les Suetes winds on Cape Breton Island blew just shy of 120 km/h. Gusts reached 100 km/h in a few places in Newfoundland. The Wreckhouse winds of Table Mountains reached 152 km/h.
Peak Provincial Wind Gusts and Rainfall for Tropical Storm Danny
Peak Provincial Wind Gusts (km/h) / Peak Provincial Rainfalls (mm)St. Paul Island, N.S. 130 / Grand Manan, N.B. 126.3
Grand Etang (Les Suetes), N.S. 118 / Saint John, N.B. 108.3
Summerside, P.E.I. 59 / Moncton, N.B. 91.8
Grand Manan, N.B. 57 / Charlottetown, P.E.I. 107.6
Wreckhouse Winds, N.L. 152 / Brier Island, N.S. 100.5
Grates Cove, N.L. 100 / Harbour Breton, N.L. 79.0
3.2 Impacts
Heavy rain throughout the Maritimes caused closures of a number of flooded roads. Water filled about 50 basements in Saint John, New Brunswick and 170 in Moncton, NB. The City of Moncton launched an investigation including computer simulated re-enactments of their drainage system to try to explain the drainage problems. It was noted that 30 year old houses had never before seen such basement flooding. The Nine Mile River in Hants County, Nova Scotia, overflowed its banks, submerging 50 caravans including cars and trucks at a nearby camping ground. Sporadic power outages occurred and a peak of 17,000 customers were without electricity as wind played havoc with the Nova Scotia power grid. In Newfoundland, Wreckhouse winds toppled two caravans leaving the ferry terminal in Port Aux Basques.
3.3 Warnings & Information Statements
Environment Canada’s Newfoundland and Labrador Weather Office in Gander and the Atlantic Storm Prediction Centre in Halifax issued a combined total of 35 public warnings for heavy rain, plus warnings for Les Suetes and Wreckhouse winds. These warnings were posted at least 24 hours ahead of the expected event. The offices posted 25 marine warnings for gale force winds. The CHC issued 15 information statements, the first during the early morning on August 28th.
3.4 Coordination and Communications Effort
During Danny’s approach and passage, Atlantic Warning Preparedness Meteorologists and Canadian Hurricane Centre forecasters conducted over 60 media interviews, and worked closely with regional emergency measures organizations, Public Safety Canada, the Royal Canadian Mounted Police, the Canadian Coast Guard, and public utility companies.
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