An off-season South Pacific tropical cyclone is a tropical cyclone that exists in the South Pacific basin outside of the official tropical cyclone season. The World Meteorological Organization currently defines the season as occurring between November 1 and April 30, of the following year, with approximately 96% of all activity occurring between these months. If a tropical cyclone should develop during the off-season, it is more likely to develop during May or October than any other month of the off-season. The official database provided by the International Best Track Archive for Climate Stewardship, which dates back to 1892, shows that 56 tropical cyclones have existed in the basin during the off-season between May and October, while in addition 36 other systems that are not included in IBTRACS have monitored by the warning centres.
Off-season cyclones are most likely to occur in the Coral Sea, with most impacting either the Solomon Islands, Vanuatu and New Caledonia. The most recent off-season storm is Tropical Depression 01F, which developed during September 2018 and impacted the Solomon Islands. The strongest tropical cyclone to exist during the off-season was Severe Tropical Cyclone Lola of 2023, with maximum 10–minute sustained winds of 130 mph (215 km/h), and an estimated value of 930 hPa (27.46 inHg) of central pressure. The deadliest and most damaging system was Severe Tropical Cyclone Namu, which caused over 100 deaths, when it impacted the Solomon Islands during May 1986.
Background
Tropical cyclones are considered to be non-frontal, low pressure systems that develop, within an environment of warm sea surface temperatures and little vertical wind shear aloft.
Within the South Pacific basin to the east of 160°E, the cyclone season is defined as running between November 1 and April 30 of the following year. During the off-season a total of 91 tropical cyclones have been recorded during the off-season, with a total of 54 of these systems occurring after satellite imagery became regularly available during the 1969–70 season.
The first system to exist in the off-season on record was active during May 17, 1868 and was located near Vanuatu, according to records compiled by Stephen Sargent Visher. However, the official database shows that the first storm to occur in the basin outside of the current season was in 1912. The most recent systems to exist in the off-season were Severe Tropical Cyclone Lola, which developed during October 2023. The strongest tropical cyclones to exist during the off-season in terms of wind speed was Severe Tropical Cyclone Donna of 2017 and Severe Tropical Cyclone Lola of 2023, with maximum 10–minute sustained winds of 125 mph (205 km/h), while the most intense by central pressure was Severe Tropical Cyclone Xavier of 2006, with a minimum value of 930 hPa (27.46 inHg). The deadliest and most damaging system was Severe Tropical Cyclone Namu, which caused over 100 deaths, when it impacted the Solomon Islands during May 1986.
Of the 57 known tropical systems that have been recorded during the off-season, a total of 33 tropical cyclones have been recorded in May or have persisted into the off-season after developing in April. A total of 18 tropical cyclones have developed during October, while three systems have been recorded in both June and July, while two have been recorded in September. The three systems recorded in June were all named tropical cyclones, with Gina and Keli considered to be a Category 3 severe tropical cyclones on the Australian tropical cyclone intensity scale. In addition Tropical Cyclone Raquel developed in June 2015 and was considered to be the latest system to develop in the South Pacific Ocean. In addition as the system persisted into July 2015, it was unofficially considered to be a part of two tropical cyclone years. Off the two systems recorded in July, Tropical Depression 17F in July 2002 was designated 17F, despite being the first system of the 2002–03 season. Tropical Depression 01F/01P of July 2015, which subsequently persisted into August 2015. The first system that developed during September was an unnamed system that occurred in 1924, which according to a report published by Greenpeace, caused damage to some ships to the west of New Caledonia. The other system was declared to be a tropical depression by the Fiji Meteorological Service during September 1999, but was more likely to be a hybrid system rather than a proper tropical depression.
The season with the most off-season systems was 1999–2000, which had a total of six tropical depressions existing during the off-season. The 1997–98, 2004–05 and 2013–14 seasons had four tropical cyclones during the off-season each, while the 1988–89 and the 1996–97 season had three off-season tropical cyclones.
Systems
The wind speeds listed are maximum ten-minute average sustained winds, while the pressure is the minimum barometric pressure, both of which are estimates taken from the archives of either the Australian Bureau of Meteorology, the Fiji Meteorological Service, and New Zealand's MetService. If there are no known estimates of either the winds or pressure then the system is listed as "Not specified" under winds or pressure, if there is no known estimated winds or pressure. For deaths and damages "None" indicates that there were no reports of fatalities or damages, although such storms may have impacted land. Where it The damage totals are the United States dollar of the year of the storm.
| Name | Dates | Peak intensity | Areas affected | Damage (USD) | Deaths | Ref(s). | ||
|---|---|---|---|---|---|---|---|---|
| Category | Wind speed | Pressure | ||||||
| Unnamed | October 5 – 6, 1847 | Not Specified | Not Specified | Not Specified | Norfolk Island | None | None | |
| Unnamed | May 17, 1868 | Not Specified | Not Specified | Not Specified | Unknown | None | None | |
| Unnamed | October 2, 1874 | Not Specified | Not Specified | Not Specified | Unknown | None | None | |
| Unnamed | May 5 – 8, 1912 | Not Specified | Not Specified | Not Specified | New Caledonia | None | None | |
| Unnamed | June 20 – 26, 1912 | Not Specified | Not Specified | Not Specified | French Polynesia | None | None | |
| Unnamed | July 11 – 16, 1912 | Not Specified | Not Specified | Not Specified | Queensland, New Zealand | None | None | |
| Unnamed | May 5 – 11, 1916 | Not Specified | Not Specified | Not Specified | New Caledonia | None | None | |
| Unnamed | May 24 – 29, 1916 | Not Specified | Not Specified | Not Specified | New Zealand | None | None | |
| Unnamed | May 14 – 20, 1919 | Not Specified | Not Specified | Not Specified | New Zealand | None | None | |
| Unnamed | July 28, 1919 | Not Specified | Not Specified | Not Specified | Unknown | None | None | |
| Unnamed | October 28 – 30, 1919 | Not Specified | Not Specified | Not Specified | Unknown | None | None | |
| Unnamed | July 20 – 28, 1921 | Not Specified | Not Specified | Not Specified | Queensland, New Zealand | None | None | |
| Unnamed | October 1 – 6, 1921 | Not Specified | Not Specified | Not Specified | Queensland, New Zealand | None | None | |
| Unnamed | September 1924 | Not Specified | Not Specified | Not Specified | Unknown | None | None | |
| Unnamed | June 1 – 7, 1925 | Not Specified | Not Specified | Not Specified | Queensland | None | None | |
| Unnamed | May 1 – 6, 1926 | Not Specified | Not Specified | Not Specified | Queensland | None | None | |
| Unnamed | May 15 – 20, 1926 | Tropical Low | Not Specified | 999 hPa (29.50 inHg) | Queensland | None | None | |
| Unnamed | May 26, 1926 | Not Specified | Not Specified | Not Specified | Fiji | Minor | None | |
| Unnamed | June 1 – 4, 1929 | Not Specified | Not Specified | Not Specified | Queensland | None | None | |
| Unnamed | July 1 – 4, 1931 | Not Specified | Not Specified | Not Specified | Queensland | None | None | |
| Unnamed | July 1 – 4, 1934 | Not Specified | Not Specified | Not Specified | Queensland | None | None | |
| Unnamed | May 24 – 27, 1935 | Tropical Low | Not Specified | 1002 hPa (29.59 inHg) | None | None | None | |
| Unnamed | August 30 – September 3, 1935 | Not Specified | Not Specified | 999 hPa (29.50 inHg) | Queensland | None | None | |
| Unnamed | July 1 – 5, 1936 | Not Specified | Not Specified | Not Specified | None | None | None | |
| Unnamed | July 7 – 10, 1936 | Not Specified | Not Specified | 1002 hPa (29.59 inHg) | None | None | None | |
| Unnamed | August 19 – 23, 1950 | Category 2 tropical cyclone | 95 km/h (60 mph) | Not Specified | None | None | None | |
| Unnamed | September 12 – 17, 1950 | Category 2 tropical cyclone | 110 km/h (70 mph) | Not Specified | New Caledonia | None | None | |
| Unnamed | October 26 – 29, 1952 | Not Specified | Not Specified | 998 hPa (29.47 inHg) | None | None | None | |
| Unnamed | June 4 – 15, 1958 | Not Specified | Not Specified | 988 hPa (29.18 inHg) | Solomon Islands, New Caledonia New Zealand | None | None | |
| Unnamed | June 4 – 12, 1958 | Not Specified | Not Specified | 986 hPa (29.12 inHg) | Queensland | None | None | |
| Unnamed | May 24 – 29, 1960 | Not Specified | Not Specified | Not Specified | Queensland | None | None | |
| Unnamed | May 2 – 9, 1963 | Not Specified | Not Specified | 1007 hPa (29.74 inHg) | Solomon Islands, Queensland | None | None | |
| Unnamed | May 7 – 14, 1963 | Not Specified | Not Specified | 1000 hPa (29.53 inHg) | Solomon Islands, Vanuatu New Caledonia | None | None | |
| Unnamed | May 10 – 12, 1963 | Not Specified | Not Specified | Not Specified | New Caledonia | None | None | |
| Unnamed | June 22 – 25, 1963 | Not Specified | Not Specified | 1001 hPa (29.56 inHg) | New Caledonia | None | None | |
| Unnamed | June 23 – July 4, 1963 | Not Specified | Not Specified | 986 hPa (29.12 inHg) | New Caledonia | None | None | |
| Esther | April 26 – May 2, 1969 | Not Specified | Not Specified | 992 hPa (29.29 inHg) | Papua New Guinea | None | None | |
| Unnamed | June 22 – 23, 1970 | Not Specified | Not Specified | Not Specified | None | None | None | |
| Nora | October 29 – 30, 1970 | Tropical depression | Not Specified | Not Specified | Fiji | Minor | None | |
| Ida | May 29 – June 5, 1972 | Category 3 severe tropical cyclone | 120 km/h (75 mph) | 965 hPa (28.50 inHg) | Solomon Islands, Vanuatu New Caledonia | 70 million | 3 | |
| Bebe | October 19 – 28, 1972 | Category 3 severe tropical cyclone | 155 km/h (100 mph) | 945 hPa (27.91 inHg) | Fiji, Kiribati, Tuvalu | 22.5 million | 27 | |
| Unnamed | July 7 – 10, 1973 | Not Specified | Not Specified | Not Specified | New Caledonia | None | None | |
| Unnamed | July 8 – 14, 1973 | Not Specified | Not Specified | Not Specified | Queensland | None | None | |
| Unnamed | July 31 – August 4, 1976 | Not Specified | Not Specified | Not Specified | None | None | None | |
| Claudia | May 13 – 18, 1981 | Category 1 tropical cyclone | 75 km/h (45 mph) | 990 hPa (29.23 inHg) | Solomon Islands | None | None | |
| Joti | October 31 – November 7, 1982 | Category 2 tropical cyclone | 110 km/h (70 mph) | 975 hPa (28.79 inHg) | Vanuatu | Minor | None | |
| Unnamed | May 11, 1983 | Tropical depression | Not Specified | Not Specified | None | None | None | |
| Unnamed | May 16, 1983 | Tropical depression | Not Specified | Not Specified | None | None | None | |
| Namu | May 15 – 22, 1986 | Category 3 severe tropical cyclone | 150 km/h (90 mph) | 955 hPa (28.20 inHg) | Solomon Islands | 20 million | 111 | |
| Blanch(e) | May 20 – 27, 1987 | Category 1 tropical cyclone | 75 km/h (45 mph) | 990 hPa (29.23 inHg) | Solomon Islands | None | None | |
| Meena | May 1 – 10, 1989 | Category 1 tropical cyclone | 85 km/h (50 mph) | 990 hPa (29.23 inHg) | Cape York Peninsula | Minor | None | |
| Ernie | May 6 – 12, 1989 | Category 1 tropical cyclone | 85 km/h (50 mph) | 990 hPa (29.23 inHg) | None | None | None | |
| Unnamed | May 28 – 30, 1989 | Tropical depression | Not Specified | Not Specified | Fiji | None | None | |
| Lisa | May 7 – 19, 1991 | Category 2 tropical cyclone | 110 km/h (70 mph) | 975 hPa (28.79 inHg) | Solomon Islands, Vanuatu | None | None | |
| Innis | April 27 – May 6, 1992 | Category 2 tropical cyclone | 95 km/h (60 mph) | 985 hPa (29.09 inHg) | Solomon Islands, Vanuatu | None | None | |
| June | May 2 – 11, 1997 | Category 2 tropical cyclone | 95 km/h (60 mph) | 985 hPa (29.09 inHg) | Fiji | 60 million | None | |
| 37P | May 28 – 30, 1997 | Tropical cyclone | Not Specified | 997 hPa (29.44 inHg) | Vanuatu | None | None | |
| Keli | June 7 – 17, 1997 | Category 3 severe tropical cyclone | 150 km/h (90 mph) | 955 hPa (28.20 inHg) | Tuvalu, Fiji, Samoan islands | 10,000 | None | |
| Lusi | October 8 – 12, 1997 | Category 2 tropical cyclone | 100 km/h (65 mph) | 985 hPa (29.09 inHg) | Vanuatu, Fiji | None | None | |
| 03P | October 26 – 28, 1997 | Tropical depression | Not Specified | 997 hPa (29.44 inHg) | None | None | None | |
| Martin | October 27 – November 5, 1997 | Category 3 severe tropical cyclone | 155 km/h (100 mph) | 945 hPa (27.91 inHg) | Cook Islands, French Polynesia | $8 million | 28 | |
| Bart | April 28 – May 3, 1998 | Category 1 tropical cyclone | 85 km/h (50 mph) | 987 hPa (29.15 inHg) | French Polynesia | Minor | 10 | |
| 26F | May 20 – 26, 1999 | Tropical depression | 75 km/h (45 mph) | 995 hPa (29.38 inHg) | Queensland, New Zealand | None | None | |
| 20F | April 26 – May 2, 2000 | Tropical depression | 95 km/h (60 mph) | 1000 hPa (29.53 inHg) | Queensland | None | None | |
| 21F | April 28 – May 2, 2000 | Tropical depression | 65 km/h (40 mph) | 1000 hPa (29.53 inHg) | Queensland | None | None | |
| 22F | May 3 – 8, 2000 | Tropical depression | 75 km/h (45 mph) | 1001 hPa (29.56 inHg) | None | None | None | |
| 23F | May 6, 2000 | Tropical depression | Not Specified | Not Specified | None | None | None | |
| 24F | May 20 – 23, 2000 | Tropical depression | 75 km/h (45 mph) | 1002 hPa (29.59 inHg) | None | None | None | |
| 14F | May 1 – 3, 2001 | Tropical depression | 75 km/h (45 mph) | 1004 hPa (29.65 inHg) | None | None | None | |
| 15F | May 7 – 9, 2001 | Tropical depression | 65 km/h (40 mph) | 999 hPa (29.50 inHg) | None | None | None | |
| 17F | July 3 – 4, 2002 | Tropical depression | Not Specified | 995 hPa (29.38 inHg) | None | None | None | |
| 01F | October 21 – 22, 2002 | Tropical depression | Not Specified | 1002 hPa (29.59 inHg) | Vanuatu | None | None | |
| Gina | June 4 – 9, 2003 | Category 3 severe tropical cyclone | 150 km/h (90 mph) | 950 hPa (28.05 inHg) | Solomon Islands | None | None | |
| 01F | October 28 – 30, 2004 | Tropical depression | Not Specified | 1001 hPa (29.56 inHg) | Solomon Islands | None | None | |
| 14F | April 14 – May 1, 2005 | Tropical depression | Not Specified | 1000 hPa (29.53 inHg) | None | None | None | |
| 17F | April 26 – May 1, 2005 | Tropical depression | Not Specified | 1007 hPa (29.74 inHg) | None | None | None | |
| 18F | April 29 – May 1, 2005 | Tropical depression | Not Specified | 1006 hPa (29.71 inHg) | None | None | None | |
| Xavier | October 20 – 26, 2006 | Category 4 severe tropical cyclone | 175 km/h (110 mph) | 930 hPa (27.46 inHg) | Solomon Islands, Vanuatu | Minimal | None | |
| 02F | October 24 – 29, 2006 | Tropical depression | Not Specified | 1004 hPa (29.65 inHg) | None | None | None | |
| 01F | October 16 – 19, 2007 | Tropical depression | Not Specified | 1000 hPa (29.53 inHg) | Solomon Islands | None | None | |
| 17F | May 10 – 11, 2011 | Tropical depression | Not Specified | 1006 hPa (29.71 inHg) | None | None | None | |
| 22F | April 28 – May 1, 2013 | Tropical disturbance | Not Specified | 993 hPa (29.32 inHg) | Fiji | None | None | |
| 01F | October 19 – 20, 2013 | Tropical disturbance | Not Specified | 1004 hPa (29.65 inHg) | Solomon Islands | None | None | |
| 02F | October 19 – 23, 2013 | Tropical depression | Not Specified | 1002 hPa (29.59 inHg) | Vanuatu | Minor | None | |
| 03F | October 21 – 22, 2013 | Tropical depression | Not Specified | 1005 hPa (29.68 inHg) | Solomon Islands | None | None | |
| 04F | October 25 – 27, 2013 | Tropical depression | Not Specified | 1007 hPa (29.74 inHg) | Solomon Islands | None | None | |
| Raquel | June 28 – July 5, 2015 | Category 1 tropical cyclone | 65 km/h (40 mph) | 995 hPa (29.38 inHg) | Solomon Islands | Significant | 1 | |
| 01F | July 29 – August 4, 2015 | Tropical depression | Not Specified | 1007 hPa (29.74 inHg) | Solomon Islands | None | None | |
| 02F | October 12 – 18, 2015 | Tropical depression | 45 km/h (30 mph) | 1001 hPa (29.56 inHg) | Vanuatu | None | None | |
| Donna | May 1 – 10, 2017 | Category 5 severe tropical cyclone | 205 km/h (125 mph) | 935 hPa (27.61 inHg) | Solomon Islands, Vanuatu New Caledonia, New Zealand | Significant | 2 | |
| Ella | May 7 – 14, 2017 | Category 2 tropical cyclone | 110 km/h (70 mph) | 977 hPa (28.85 inHg) | Samoan Islands, Tonga Wallis and Futuna, Fiji | Minor | None | |
| Liua | September 26 – 28, 2018 | Category 1 tropical cyclone | 75 km/h (45 mph) | 994 hPa (29.35 inHg) | Solomon Islands | None | 0 | |
| 12F | May 16 – 21, 2019 | Tropical disturbance | Not Specified | 1004 hPa (29.65 inHg) | None | None | 0 | |
| Gina | May 16 – 21, 2022 | Category 1 tropical cyclone | 75 km/h (45 mph) | 998 hPa (29.47 inHg) | Vanuatu | Unknown | Unknown | |
| Lola | October 19 –27, 2023 | Category 5 severe tropical cyclone | 215 km/h (130 mph) | 930 hPa (27.46 inHg) | Solomon Islands, Vanuatu | |||
Systems by month
Off-season systems are most likely to occur in May, with a total of 43 systems developing or persisting into the month, during October, when 22 have formed. By contrast, only 2 systems have developed in August and 4 in September.
| Month | Number of cyclones |
|---|---|
| April | |
| May | |
| June | |
| July | |
| August | |
| September | |
| October |
See also
wikipedia, wiki, encyclopedia, book, library, article, read, free download, Information about List of off-season South Pacific tropical cyclones, What is List of off-season South Pacific tropical cyclones? What does List of off-season South Pacific tropical cyclones mean?