The 1996–97 South Pacific cyclone season was one of the most active South Pacific tropical cyclone season's on record, with 12 tropical cyclones officially occurring within the South Pacific Ocean basin between 160°E and 120°W. The season officially started on November 1, 1997 with the first tropical cyclone developing on November 23 while the season ended later than normal on June 17, when Cyclone Keli dissipated. The strongest tropical cyclones during the season was Cyclone Gavin which had a minimum pressure of 925 hPa (27.32 inHg). After the season had ended 4 tropical cyclone names were retired from the naming lists, after the cyclones had caused significant impacts to South Pacific islands.
During the season, tropical cyclones were officially monitored by the Regional Specialized Meteorological Center (RSMC) in Nadi, Fiji and the Tropical Cyclone Warning Center in Wellington, New Zealand. Throughout the season the United States Navy also monitored the basin and issued unofficial warnings, through its Joint Typhoon Warning Center (JTWC) and Naval Pacific Meteorology and Oceanography Center (NPMOC). Tropical cyclones that were located between 160°E and 120°W as well as the Equator and 25°S were monitored by TCWC Nadi while any that were located to the south of 25°S between 160°E and 120°W were monitored by TCWC Wellington. During the season the JTWC issued warnings on any tropical cyclone that was located between 160°E and the 180° while the NPMOC issued warnings for tropical cyclones forming between 180° and the American coast. RSMC Nadi and TCWC Wellington both used the Australian tropical cyclone intensity scale, and measured windspeeds over a 10-minute period, while the JTWC and the NPMOC measured sustained windspeeds over a 1-minute period.
Ahead of the South Pacific tropical cyclone Season starting on November 1, 1996, a weak to moderate La Nina episode persisted throughout 1996, however during the season it started to break down as the El Nino Episode of 1997-98 developed with the South Pacific Convergence Zone becoming more active.
Cyclone Fergus brought torrential rain and damaging winds to parts of the North Island of New Zealand. There was no loss of life, in part because of timely warnings about the ferocity of the storm. Damages from the storm were at least $2 million.
Heavy rains accompanied the storm, peaking at 474 mm (18.7 in) in Dzumac. La Foa also recorded 202 mm (8.0 in) of rain. Wind gusts reached 165 km/h (105 mph) in Koumac. Flooding from the storm caused a total loss of crops and the high winds knocked out power and communication to most of the island.
Early on February 22, the JTWC reported that a Tropical Disturbance had formed about 510 km (320 mi) to the northeast of Tahiti. The disturbance gradually developed over the next few days until February 25 when it was classified as Tropical Storm 29P. Later that day the cyclone reached its 1 minute peak strength of 85 km/h (50 mph), whilst located within TCWC Wellingtons area of responsibility. It stayed at its 1 minute peak strength until its extratropical transition started late on February 26. Whilst the Cyclone was active neither RSMC Nadi or TCWC Wellington monitored it as a Tropical Cyclone, however TCWC Wellington reported in their post season analysis that it should have been a Category 2 Cyclone with peak winds of 110 km/h (70 mph).
to the southwest of the Fijian dependency: Rotuma. During the next day, as the JTWC designated the depression as Tropical Cyclone 33P, the system started to move move northwards slowly, before during March 15, RSMC Nadi reported that the system had developed into a category 1 tropical cyclone on the Australian scale and named it Hina.
Cyclone Hina caused widespread damage in Tonga, leaving roughly $14.5 million in damages. About 320 families were left homeless after the storm.
Late on May 26, the JTWC reported that a tropical disturbance had developed about 630 km (390 mi), to the north of Port Villa in Vanuatu. During the next day the disturbance gradually developed further before the JTWC issued a tropical cyclone formation alert. On May 28, the JTWC designated the disturbance as Tropical Cyclone 37P, as they expected it to intensify further with windspeeds expected to become equivalent to a tropical storm. Over the next day, the system moved towards the southeast between a mid level ridge of high pressure and a trough of low pressure, before the JTWC reported that the depression had become a tropical storm and reached its peak 1-minute sustained windspeeds of 65 km/h (40 mph). On May 30, the JTWC reported that the cyclone had dissipated over cooler water and encountered stronger vertical windshear.
Early on June 7, RSMC Nadi reported that a tropical depression had formed about 460 kilometers (290 mi) to the north of Tokelau. The depression gradually developed over the next few days whilst moving to the southwest with a Tropical Cyclone Formation Alert issued on June 9. Before it got designated as Tropical Cyclone Keli by RSMC Nadi and Cyclone 38P by the NPMOC early the next day. Cyclone Keli intensified slowly reaching its 10-minute peak windspeeds of 150 km/h, (90 mph), which made it a category three severe tropical cyclone, on the Australian Tropical Cyclone Intensity Scale early on June 12 with 1-minute peak wind-speeds of 215 km/h (130 mph), also being reported later that day. As it came under the influence of strong mid latitude westerlies and moved into an area of strong vertical windshear the cyclone started to weaken with it being declared as extratropical by the JTWC on June 15. However RSMC Nadi continued issuing warnings on Keli until early the next day when they passed primary warning responsibility for the system to TCWC Wellington, who monitored the system until it was last noted on July 17.
Cyclone Keli struck the islands of Tuvalu on June 12 and 13, with extensive damage reported throughout the Islands with trees uprooted by wind and waves. On Nivalakita all buildings except for the church were flattened with an estimated cost to rebuild the houses exactly as they were was estimated at &10000000000012000000000A$12 thousand
). Whilst the whole of Tepuka Savilivili was left uninhabitable as coconut trees and other vegetation were swept away with no more than an area of jagged coral left behind. In Fiji, Strong winds and rough seas were reported from the cyclone as it was moving to the north of Fiji near to Rotuma, and whilst the Cyclone was weakening 3.76 in (96 mm) of rain was reported on American Samoa.
In the South Pacific as soon as a tropical depression reaches Cyclone strength it is named by the warning centre which is either the Regional Specialized Meteorological Centre in Nadi, or the Tropical Cyclone Warning Center in Wellington, New Zealand. If a tropical depression should become a tropical cyclone in the TCWC Wellington area of responsibility, TCWC Wellington, in consultation with RSMC Nadi, will name the cyclone by using the next name from the list.
After the season ended, the names Drena, Gavin, Hina and Keli were retired from the list of names for the South Pacific Ocean.
They were replaced by the names Daphne, Garry, Haley and Koko respectively
This table lists all the storms that developed in the South Pacific basin, to the east of 160E during the 1996–97 season. It includes their intensity on the Australian tropical cyclone intensity scale, duration, name, areas affected, deaths, and damages. For most storms the data is taken from TCWC Nadi and Wellingtons archives, however data for 37P has been taken from the JTWC archives rather than RSMC Nadi and TCWC Wellingtons archives, and thus the winds are a period of 1-minute sustained as opposed to 10-minutes.
↑ 8.08.18.28.38.48.5RSMC Nadi — Tropical Cyclone Centre, TCWC Brisbane, TCWC Wellington (May 22, 2009). TCWC Wellington Best Track Data 1967–2006. Fiji Meteorological Service, Meteorological Service of New Zealand Limited, Australian Bureau of Meteorology. International Best Track Archive for Climate Stewardship.