Cyclone Susan
Severe Tropical Cyclone Susan was a powerful tropical cyclone that is one of the most intense tropical cyclones#South Pacific Ocean|the most intense] on record within the South Pacific basin. It was first noted on December 20, 1997, as a weak tropical disturbance located to the north of American Samoa. Over the next 12 days, the disturbance remained weak while it gradually moved towards the southwest before it started to rapidly develop on January 2, 1998 while it was located near the Fijian dependency of Rotuma. The disturbance was declared a tropical cyclone later that day, but was not named Susan until the next day, after it had intensified into a category 2 tropical cyclone on the Australian Scale. Over the next few days, Susan moved towards the southwest and continued to intensify before it reached its peak intensity as a category five tropical cyclone during January 5 while it was located about to the northwest of Vanuatu's capital city Port Vila.
At this stage as the cyclone was moving towards the southwest it posed a severe threat to Vanuatu however, during that day Susan recurved towards the southeast and subsequently spared Vanuatu a direct hit. After sparing Vanuatu a direct hit, Susan started to accelerate towards the southeast and while starting to weaken significantly passed close enough to Fiji during January 7 and 8 to cause gale-force winds in Fiji's southern and western islands. While continuing to move towards the southeast, Susan started to interact with Severe Tropical Cyclone Ron during January 8 before it absorbed Ron by 0600 UTC the next day and starting to transition into an extratropical cyclone.
The extratropical remnants of the combined systems were then monitored for another day until they were last noted on January 10, bringing an unseasonable cold snap to New Zealand. Despite sparing Vanuatu and Fiji direct hits, heavy rain and gale-force winds associated with Susan were reported to have caused minor damage to several Vanuatuan and Fijian islands. These islands included Viti Levu where a possible tornado destroyed the roof of a shopping centre and the Vanuatuan island of Ambrym, where a woman died after being hit by a falling coconut tree, while gathering supplies to secure her house with.
Meteorological history
During December 20, 1997, the Fiji Meteorological Service started to monitor a weak tropical disturbance, that was located about to the northwest of Pago-Pago in American Samoa. Over the next couple of weeks, the system gradually moved towards the west-southwest, without developing into a tropical cyclone. During the opening days of January 1998, a subtropical mid-level ridge of high pressure developed inbetween Fiji and Vanuatu to the south of the system, which provided an area of low vertical wind shear for the disturbance to intensify in. As a result, the system started to show signs of significant development while located near the Fiji dependency of Rotuma, before early on January 3, the United States Joint Typhoon Warning Center initiated warnings on the system and designated it as Tropical Cyclone 11P. This was followed by the FMS who reported that the system had become a List of Category 1 [South Pacific tropical cyclones|category 1 tropical cyclone], on the Australian tropical cyclone intensity scale and named it Susan.After it had been named, Susan continued to move towards the west-southwest and started to pose a severe threat to northern Vanuatu, as it continued to rapidly intensify. It was classified as a category 3 severe tropical cyclone during January 4, as an eye appeared on satellite imagery, atmospheric convection increased and clouds tops significantly cooled. The ridge of high pressure also started to weaken as it interacted with a trough of low pressure, which meant that the cyclone started to turn towards the south-southwest.
During January 5, the FMS reported that along with Severe Tropical Cyclone Ron, Susan had become a category 5 severe tropical cyclone and that both systems had peaked with 10-minute sustained wind speeds of and a minimum pressure of. As a result, both systems were considered to be two of the most intense tropical cyclones, within the South Pacific basin, since Severe Tropical Cyclone Hina of 1984-85. At around the same time, the JTWC who reported that the system had peaked with 1-minute sustained wind speeds of, which made it a category 5 on the Saffir-Simpson hurricane wind scale. As it peaked in intensity, Susan was located about to the northeast of Port Vila in Vanuatu and had started to recurve by 70 degrees towards a large weakness in the subtropical ridge.
Over the next couple of days, Susan maintained its peak intensity and accelerated south-eastwards, as it came under the influence of a north-westerly steering flow, which was associated with a trough of low pressure. As a result, the system started to pose a threat to the island nation of Fiji and weaken as it interacted with cooler sea surface temperatures, cooler air and increased vertical windshear. During January 7, Susan's eye became ragged as it continued to weaken, with the FMS reporting that the system had weakened into a category 4 severe tropical cyclone. During that day, the system passed close enough to Fiji, to produce gale-force winds over several of the southern and western Fijian Islands. Susan subsequently absorbed the remnants of Severe Tropical Cyclone Ron during January 8, before it rapidly weakened and quickly transitioned into an extratropical cyclone, while it was located about to the northeast of Auckland, New Zealand. The combined system was monitored for another day, before it was last noted during January 10, bringing an unseasonable cold snap to New Zealand.
Effects
Cyclone Susan caused one death and at least worth of damage, when it affected the Solomon Islands, Vanuatu and Fiji during January 1998. Due to the impact of this storm, the name Susan was retired from the lists of tropical cyclone names for the South Pacific. Between January 2–5, the system impacted the Solomon Islands Temotu province, where it caused damage to several food gardens and destroyed several houses.Vanuatu
After Susan had been named on January 3, the FMS started to issue special weather bulletins for Vanuatu, which indicated that gale-force winds might impact the northern islands within the next 24-48 hours. The Vanuatu National Disaster Management Council subsequently issued various colour-coded tropical cyclone alerts which warned residents about the approaching cyclone, including a red alert for Ambae Maewo and Pentecost islands on January 5. Ahead of the cyclone impacting the island nation, ships and small boats were advised to seek safe anchorage, residents were advised to stay at home, while the domestic airline Vanair cancelled its flights and closed all of its airfields. On the island of Ambrym, a lady was killed by a falling coconut tree, as she collected fronds and tree branches to help protect her home against Susan.Despite being spared a direct hit, heavy rain and gale-force winds caused minor damage to several Vanuatuan Islands, including on Ambrym Island, where a woman died after being hit by a falling coconut tree, while gathering supplies to secure her house with. After the alerts were cancelled on January 7, by the National Disaster Management Council, most shops and government buildings on Efate island kept their shutters up because Cyclone Katrina was predicted to directly affect the archipelago within a few days.