Any disturbances forming in the region were designated with a sequential number suffixed by the letter F. In addition, the United States Military's Joint Typhoon Warning Center unofficially monitored parts of the basin during the season, where any systems judged to have achieved tropical storm strength or greater received a number suffixed with the letter P. RSMC Nadi and TCWC Wellington both use the Australian Tropical Cyclone Intensity Scale, and measure wind speeds over a period of ten minutes, while the JTWC measures sustained winds over a period of one minute which can be applied to the Saffir–Simpson hurricane scale.
Seven named storms formed or moved into the South Pacific basin during the 2010–11 season, the strongest of which was Severe Tropical Cyclone Wilma in late January.
Ahead of the cyclone season, RSMC Nadi, TCWC Wellington, the Australian Bureau of Meteorology (BoM), the New Zealand National Institute of Water and Atmospheric Research (NIWA) and various other Pacific Meteorological services, all contributed towards the Island Climate Update tropical cyclone outlook that was released during October 2010.
[2] In addition to contributing towards the Island Climate Update outlook, RSMC Nadi and the BoM issued their own seasonal forecasts for the South Pacific region.
[1] They also reported that the tropical cyclone genesis trough was expected to be located within the Coral Sea area near to and to the west of the International Date Line.
[1] This was based on the expected and predicted ENSO conditions, and the existence of the Pacific warm pool of sub-surface temperature anomalies in this region.
[1][2] It was also predicted that the risk of tropical cyclones affecting island nations located to the east of the International Date Line would be reduced during the season.
[2] It was predicted that Papua New Guinea, Vanuatu, New Caledonia, New Zealand and the Solomon Islands had an elevated chance of being affected by a single or multiple tropical cyclones.
[8] Situated along the eastern edge of an upper-level trough, the depression tracked towards the east-southeast and would keep this general motion for several days.
[14][15] On November 26, a tropical cyclone alert was issued for Fiji as the depression was expected to bring heavy rains and strong winds to the region.
[31] As Zelia started weakening and was no longer predicted to affect Fiji, RSMC Nadi issued their final Tropical Disturbance Advisory.
The Australian Bureau of Meteorology reported that the island could experience gale-force winds and waves of 7 metres (23 ft).
[44] A few hours later, TCWC Wellington took full responsibility of Wilma, and downgraded it into a Category 3 Severe Tropical Cyclone.
[46] On January 28, the JTWC, issuing their final warning, reported that the system took a southeast curve along the coast of North Island, New Zealand and started becoming extratropical.
[50] After Wilma moved over American Samoa, a tropical cyclone alert was issued in Tonga and Lau Islands.
[54] Late on January 21, RSMC Nadi reported that Tropical Disturbance 07F had developed about 570 km (350 mi) to the northwest of Nouméa, in New Caledonia.
[56] Early on January 22, RSMC Nadi released their final advisory on the tropical depression as it passed into TCWC Wellington's area of responsibility.
[63][64] Early the next day, RSMC Nadi reported that the depression had intensified into a category one tropical cyclone and named it Yasi, while it was located about 510 km (320 mi) to the northeast of Port Vila in Vanuatu.
Early on February 5, RSMC Nadi reported that Tropical Disturbance 10F, had developed about 200 km (125 mi), to the south east of Nukualofa in Tonga.
[81] Early on February 13, RSMC Nadi reported that Tropical Disturbance 11F had formed about 65 km to the southwest of Port Vila in Vanuatu.
[85] Early on January 18, deep convection started developing over the Low-level Circulation Center (LLCC) which is very favorable for Tropical cyclogenesis.
[92] Early on February 23, Atu crossed 25°S and entered TCWC Wellington's area of responsibility as a Category 3 Severe Tropical Cyclone.
[96] Relief operations across Vanuatu related to Cyclone Vania were temporarily halted due to dangerous conditions produced by Atu.
Still recovering from Cyclone Vania the previous month, Atu damaged or destroyed the remaining crops left in the province.
[101] A month after Atu's passage, residents in eastern Tanna reported that they had received no aid from the government despite shipments reaching less affected areas.
The National Disaster Management Office later admitted that they did not have enough rice to distribute to all affected areas and received misinformation from survey teams.
[102] On March 22, RSMC Nadi analyzed that a Tropical Disturbance had formed about 70 miles NNW of Fonualei island, Tonga.
As it neared the International Date Line it continued to strengthen and was named Tropical Cyclone Bune, and as it moved generally southwards it reached category 3 by March 25.
[111][112] Tropical Depression 15F developed during April 16, within an area of moderate vertical windshear about 600 km (375 mi) to the east of New Caledonia.
[116][117] The final tropical depression of the season developed during 10 May, within an area of moderate to high vertical windshear, about 155 km (95 mi) to the northeast of Avarua on the Southern Cook island of Rarotonga.