WORLD METEOROLOGICAL ORGANIZATION ________________ RAIV/HC-XXXIV/Doc. 4.2(8) (06.II.2012) ________ RA IV HURRICANE COMMITTEE THIRTY-FOURTH SESSION ITEM: 4.2 PONTE VEDRA BEACH, FL, USA 11 TO 15 APRIL 2012 Original: ENGLISH REVIEW OF THE PAST HURRICANE SEASON Reports of hurricanes, tropical storms, tropical disturbances and related flooding during 2011 (Submitted by Canada) RA-IV/HC-XXXIV/Doc. 4.2(8), p. 2 Canadian Hurricane Centre Meteorological Service of Canada 45 Alderney Drive Dartmouth, Nova Scotia B2Y 2N6 CANADA Website: http://www.hurricanes.ca 2011 TROPICAL CYCLONE SEASON SUMMARY Eight tropical cyclones entered the Canadian Hurricane Centre (CHC) Response Zone (RZ) in 2011 but four of those were on the very edge of the zone. The CHC issued bulletins on eight storms in total. The four main events were Hurricane Irene entering Quebec from northern New Hampshire on August 29th as a post-tropical storm, Hurricane Katia tracking well offshore south of Newfoundland on September 10th, Hurricane Maria which made landfall as a weak category-1 storm in Newfoundland on September 16th, and Hurricane Ophelia entering the RZ as a category-3 storm and land falling in Newfoundland as a strong post-tropical storm on October 3rd. Of these four storms Irene had the greatest impact on Canadian forecast territory in 2011. Gusty winds and heavy rainfall created problems in Quebec. Rivers flooded and damage to roads and bridges was experienced. Winds broke tree branches and caused some interruptions to electrical service. Katia was primarily a wave event creating spectacular ocean swells along the Atlantic Coast of Nova Scotia. Maria and Ophelia took direct aim on Newfoundland, but did not cause significant issues and were much less severe than Hurricane Igor of the previous year. BULLETIN SUMMARIES Hurricane Information Statements (WOCN3X/4X CWHX) Number of Storms Represented by these Bulletins 2011 2010 2009 2008 2007 2006 2005 2004 2003 99 79 37 90 48 93 87 104 113 8 4 2 6 4 5 7 8 8 Below is a summary of the 4 main tropical events affecting Canadian territory in 2011 comprising 85% of CHC’s forecast statements for the season. The remaining 15% were for weaker storms, including nine statements issued for Tropical Storm Gert in mid September. Gert dissipated without affecting the Canadian marine forecast district. RA-IV/HC-XXXIV/Doc. 4.2(8), p. 3 Hurricane Irene Storm Hurricane Irene made two U.S. landfalls – the first in North Carolina and the second over western Long Island near New York City. Irene was a very large and damaging storm affecting a large population of the eastern U.S. The storm weakened to tropical storm strength quickly after landfall and underwent transition to post-tropical over northern New Hampshire on August 29th. The centre of the low then tracked along the Quebec/Maine border, north of the Gaspe region of Quebec and into Labrador. As Irene underwent transition to extratropical, a sharp warm front formed over the St Lawrence River valley, enhancing wind and precipitation in that region. Conditions The heaviest rainfall from Irene in Canada was experienced in southern Quebec (see table below) where 150 mm fell in the hilly Charlevoix region on the north side of the St. Lawrence River. Montreal received near 65 mm of rain, most of which fell over a 5-hour period on August 28th. Up to 90 mm of rain fell east of the storm track over northern New Brunswick. Generally less than 25 mm fell over Nova Scotia. The strongest winds blew from the northeast along the St. Lawrence River southwestward to Montreal where gusts were near 80 km/h. These winds were associated with the warm front north of Irene and exceeded 100 km/h at a few exposed island locations (see table below). East of the storm track winds gusted to near 90 km/h over the Maritime Provinces. These winds generated choppy conditions in local harbours around the region. Station Ile D’Orleans, QC Ile Aux Grues, QC Pointe De L’Islet, QC Summerside, PEI Moncton, NB Yarmouth, NS Monctreal, QC Fredericton, NB WindGusts (km/h) 113 (92 sust.) 104 (78 sust.) 98 96 93 93 78 78 Station Charlevoix, QC Thetford Mines, QC Sherbrooke, QC Doaktown, NB Montreal, QC Rainfall (mm) 150 109 107 89 66 Impacts Flooding occurred over parts of southern Quebec resulting in some road washouts and causing one direct fatality when a vehicle was swept into a river northeast of Montreal after a large culvert collapsed beneath the road. Winds brought down several trees in Quebec and New Brunswick leaving tens of thousands of people without electricity. Rough seas and some large waves caused minor problems along the coast. In southern New Brunswick, waves were spreading rocks and other debris across a road near a popular beach. RA-IV/HC-XXXIV/Doc. 4.2(8), p. 4 (Left): Irene flooding caused damage on Route 138 Saint-Simeon, QC (Marika Wheeler/CBC) (Right): Tree-related damage in Charlotteown, PEI (The Guardian) Warnings & Information Statements There were 26 unique information statements (WOCN31 CWHX) issued by the CHC for this event. Tropical storm warnings were posted over the southwestern Maritime Provinces. Regular wind and rainfall warnings were issued in Quebec since the storm had become post tropical as it was affecting that region. The transition was most apparent with the warm front development combined with topographic effects on the wind in the St. Lawrence Valley region. Gale to storm-force wind warnings were issued for most Atlantic Canada waters and the St. Lawrence River region. Coordination and Communications Effort The CHC conducted daily conference calls at 3:30 pm ADT for operational weather offices in Eastern Canada. These included the Quebec Storm Prediction Centre, Canadian Meteorological Aviation Centre, Atlantic Storm Prediction Centre, and other groups including Warning Preparedness Meteorologists in Quebec and Atlantic Canada. Planning meetings were held daily around 9:30 am ADT with Environment Canada Department Heads in Atlantic and Quebec regions to maintain coordination on various activities. Daily briefings were given by the Warning Preparedness Meteorologists for Sécurité Civile du Quebec and emergency managers in the Maritimes, both federally and provincially. Hurricane Katia Storm Hurricane Katia formed off the Cape Verde Islands on August 30 th and travelled northwestward for almost 9 days, intensifying to category-4 strength briefly on September 6th. With its persistent northwestward tracking, Katia generated large waves that crashed ashore over the Atlantic coast of Nova Scotia and southern coast of Newfoundland. On September 9th, Katia took a sharp turn toward the northeast and accelerated rapidly on RA-IV/HC-XXXIV/Doc. 4.2(8), p. 5 September 10th while passing south of Newfoundland and undergoing extratropical transition. Conditions The lowest estimated pressure over Canadian waters was 955 mb which occurred during the latter stage of extratropical transition. Although the cloud shield associated with Katia shrouded much of the Atlantic Provinces, the precipitation stayed well offshore. Rainfall at Sable Island (about 300 km north of Katia’s centre) was only 20 mm but totals between 60 and 120 mm would have been likely if the centre tracked over land. Offshore waters south of the Atlantic Provinces were hardest hit with peak waves above 10 metres. The Atlantic coast of Nova Scotia experienced heavy surf on Friday, September 9th (see photograph below) and these conditions spread to the south coast of Newfoundland on the 10th. Details from Canadian offshore buoys: Buoy Laurentian Fan 44141 Tail-of-the-Bank 44140 SW Grand Banks 44138 East Scotia Slope 44137 Halifax Harbour 44258** Max wind * Sust./gust (kts) 46/59 63/M 36/47 36/46 19/23 Significant Wave Height (m) 7.7 7.6 6.6 6.0 2.7 Maximum Wave Height (m) 12.3 11.6 13.6 9.9 4.8 * Sustained wind is a 10-minute mean at the 5-m level above water surface. Gust is a 5-s peak over a 10 minute interval near the top of the reporting hour ** Due primarily to swell Katia-spawned waves at Lawrencetown, Nova Scotia – September 9th, 2011 (Chris Fogarty) RA-IV/HC-XXXIV/Doc. 4.2(8), p. 6 Impacts The only known impact to land territory was minor wash-up of debris from large waves travelling north of the hurricane. At least one incident was reported along the south shore of Nova Scotia when someone was caught up in rip currents at a local beach. Warnings & Information Statements There were 22 unique information statements issued by the CHC for this event. No warnings were issued for land territory except a special statement for abnormal coastal water levels around the eastern portion of Newfoundland due to a known oceanographic phenomenon (a “rapid tide” effect) that has caused flooding in the past. The predicted oscillations in water levels did occur but fortunately were not present at high tide. Storm and hurricane-force wind warnings were posted for offshore waters in Canadian territory. Coordination and Communications Effort The Newfoundland and Labrador Weather Office in Gander and the Canadian Hurricane Centre in Dartmouth maintained close communication while Katia was affecting offshore waters. Special attention was given to the coastal water level statement to ensure clear terminology and communication to the public. Warning Preparedness Meteorologists coordinated with provincial and federal emergency management officials. Hurricane Maria Storm Maria formed on September 7th in the mid tropical Atlantic and tracked westward then northwestward, skirting the Caribbean Islands from September 10th to 12th. Maria – while still a tropical storm – moved northward to the west of Bermuda and attained hurricane status on September 15th at 35oN latitude. Hurricane Maria accelerated toward the northeast thereafter, making landfall in Newfoundland on the afternoon of September 16th as a weak hurricane in the Cape St. Mary’s/Argentia area of the Avalon Peninsula. After transition to a post-tropical storm while exiting Newfoundland, Maria merged with a large non-tropical low that had been intensifying over southeastern Labrador. The combined low was actually a more potent storm for northern Newfoundland and Labrador on September 17th. RA-IV/HC-XXXIV/Doc. 4.2(8), p. 7 GOES VIS image of Maria approaching Newfoundland Conditions The central pressure of Maria at landfall was estimated to be 985 mb. Strongest winds with the storm were to the right of its track. The highest winds were far enough from the centre at landfall such that they did not pass over land. The maximum wind jet was just offshore to the east of the Avalon Peninsula. The remnant eye of Maria covered most of Placentia Bay and up into the Clarenville area of the province just prior to nightfall. Winds were observed diminishing to light as the “eye” passed with partially clearing skies, followed by a modest increase in wind speed and returning cloud cover after the centre moved away. The storm was a very close call for the island region. Offshore winds blew at hurricane force for at least two hours about 180 km east of the storm track. Satellite imagery indicated that the radius of maximum wind tracked about 50 km east of Cape Spear – the island’s most easterly point of land. Storm surge was not a threat, owing to the fast motion of Maria and the limited time for water to build up into the bays. Wind and rainfall data can be found in the following table: Station Cape Pine, NL* Cape Race, NL Grates Cove, NL Argentia, NL St. John’s, NL WindGusts (km/h) 103 100 (67 sust.) 87 85 80 * Private or volunteer observation Station St. Lawrence, NL Burgeo, NL Argentia, NL Bonavista, NL St. John’s, NL Rainfall (mm) 63 61 30 25 13 RA-IV/HC-XXXIV/Doc. 4.2(8), p. 8 Buoy SW Grand Banks 44138 Nickerson Bank 44251 Laurentian Fan 44141 Banqureau Bank 44139 East Scotian Slope 44137 Tail-of-the-Bank 44140 Max wind * Sust./gust (kts) 52/70 38/49 43/58 30/38 27/35 30/37 Significant Wave Height (m) 6.4 5.9 5.9 5.4 5.3 3.4 Maximum Wave Height (m) 10.5 12.2 9.8 8.8 8.6 6.6 * Sustained wind is a 10-minute mean at the 5-m level above water surface. Gust is a 5-s peak over a 10 minute interval near the top of the reporting hour Impacts Impacts from Maria were quite minor, since the highest winds remained offshore. There were only a few reports of light objects being blown off private properties. For a land falling hurricane, there were surprisingly no interruptions to the power grid. Warnings & Information Statements There were 18 unique information statements issued by the CHC for this event. A hurricane warning was issued for the southern part of the Avalon Peninsula of Newfoundland while a tropical storm warning was posted for remaining parts of the peninsula as well as the Burin and Bonavista Peninsulas. The strong winds did not materialize over land, and the warnings were quickly ended once forecasters became aware that the highest winds were remaining offshore. Storm and hurricane-force wind warnings were issued for marine forecast regions near and to the east of Maria’s track. Hurricane conditions did materialize over the southwestern Grand Banks district. Coordination and Communications Effort Close communication was maintained between the Newfoundland and Labrador Weather Office in Gander and the Canadian Hurricane Centre in Dartmouth. Technical media briefings via WebEx were given during the days prior to the storm’s arrival by the Head of the CHC and the Warning Preparedness Meteorologist. Warning Preparedness Meteorologists took part in regular federal and provincial emergency management briefings for the island of Newfoundland leading up to the event. During the evening of September 15th, the National Hurricane Center changed the forecast from a glancing-blow tropical storm to a direct-hit hurricane landfall in Newfoundland. After a detailed discussion between the NHC and the CHC, a decision was made to issue a tropical storm warning and hurricane watch for the Avalon Peninsula, with a lead time of about 21 hours. The hurricane centers continued to coordinate on watches and warnings for the remainder of the event. RA-IV/HC-XXXIV/Doc. 4.2(8), p. 9 Hurricane Ophelia Storm Ophelia formed in the mid tropical Atlantic on September 21 st and tracked northwestward as a tropical storm over the following week. It was not until September 30 th when Ophelia began to move on a more northerly course that it strengthened to hurricane strength. In fact, Ophelia rapidly intensified from tropical storm strength to category-3 intensity in 24 hours. The storm intensified further to a 940-mb category-4 hurricane while tracking northeast of Bermuda on October 2 nd. The compact hurricane entered the CHC Response Zone as a strong category-3 then rapidly weakened as it travelled over cooler ocean water temperatures. The weakening occurred quickly enough so that Ophelia dropped below hurricane strength as it made landfall on the Avalon Peninsula of Newfoundland near the community of Placentia. The storm centre appeared to reform approximately 50 km north of landfall, then track north of the capital city of St. John’s. Conditions The central pressure of Ophelia was estimated to be 988 mb at landfall. Maximum winds at landfall were near 55 or 60 kts (100-110 km/h) about 50 km offshore. Wind gusts to 100 km/h were reported along the immediate southern coastlines of the Avalon and Burin Peninsulas. Inland gusts near 80 km/h were reported. These wind speeds are not unusual for Newfoundland. Winds noticeably diminished as the centre of the storm passed through, then increased from the west, gusting to near 90 km/h after the storm core moved away. The primary wind and rainfall figures are found in the table below. Rainfall was light near the center of the storm and to its right, as is typical for extratropical transition. Not far to the left of the track, heavy rainfall came quickly – amounting to near 50 mm in 3 hours. In the offshore region, the axis of maximum winds extended from the Laurentian Fan forecast district to the northern Grand Banks. The large waves generated by these winds (see table below) propagated northward reaching the coast of the Avalon region with heights of 5 to 10 metres. Like Maria, two-and-a-half weeks prior, storm surge was not a significant factor. The highest reading from a tide gauge was 50 cm at Argentia, which occurred at low tide. Station Cape Race, NL St. Pierre/Miquelon, FR St. John’s, NL Sagona Island, NL WindGusts (km/h) 98 (67 sust.) 98 (68 sust.) 78 (61 sust.) 96 (85 sust.) Station Bonavista, NL St. Lawrence, NL Terra Nova Park, NL St. John’s, NL Gander, NL Rainfall (mm) 62* 58* 47 27 27 * peak one-hour rainfall just over 20 mm and 3-hr totals near 50 mm Buoy Laurentian Fan 44141 Banqureau Bank 44139 Max wind * Sust./gust (kts) 52/70 43/57 Significant Wave Height (m) 13.8 11.9 Maximum Wave Height (m) 21.8 22.2 RA-IV/HC-XXXIV/Doc. 4.2(8), p. 10 Nickerson Bank 44251 East Scotian Slope 44137 SW Grand Banks 44138 36/46 23/29 34/42 8.6 7.3 6.7 15.1 12.1 15.0 * Sustained wind is a 10-minute mean at the 5-m level above water surface. Gust is 5-s peak over a 10 minute interval near the top of the reporting hour Impacts Impacts from Ophelia primarily came in the form of flooding due to rainfall. The region most affected by heavy downpours was the Burin Peninsula which was also hit hard during Hurricane Igor the previous year. A drainage ravine overflowed in the town of Belleoram, sending a cascade of rocks, mud and water into some homes causing heavy damage to a couple of buildings. A brief state of emergency was declared in the community. In the photograph below, a large culvert was unearthed by the heavy water flow from Ophelia. The same location was the site of a major washout the previous from Hurricane Igor. (Left): Large culvert unearthed on the Burin Peninsula – Cynthia Farrell/Southern Gazette (Right): Cascade of rocks caused by flash flooding in Belleoram – RCMP “B” Division, NL Curious spectators attracted by the large ocean swell along the southern coastlines were encouraged to stay well away from the wave-breaking zones as dangerous surf and rip tides were created. There was some beachfront debris and wash-up in prone areas of the southern Avalon Peninsula such as along a beach and causeway in the community of Saint Vincent’s. Warnings & Information Statements There were 18 unique information statements issued by the CHC for this event. The CHC maintained a conservative forecast for this event, issuing nothing “stronger” than a tropical storm watch for the Avalon Peninsula of Newfoundland. However, hurricane-force warnings were issued for the offshore forecast district. Rainfall warnings were issued for the hardest-hit areas including the Burin Peninsula. RA-IV/HC-XXXIV/Doc. 4.2(8), p. 11 Coordination and Communications Effort Similar to Hurricane Maria, close coordination was maintained between the Newfoundland and Labrador Weather Office and the Canadian Hurricane Centre. The CHC emphasized the importance of not over-warning the winds for the event. Regular briefings took place between federal and provincial emergency managers. The conservative approach certainly paid off, as Ophelia’s winds fell short of the conventional wind warning criteria for the island (gusts of 100 km/h or more). _______