2020–21 South Pacific Cyclone Season
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The 2020–21 South Pacific cyclone season was an average season where most
tropical cyclones A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...
formed within the
South Pacific Ocean South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþaz ...
to the east of 160°E. The season officially started on November 1, 2020, and officially ended on April 30, 2021, however a tropical cyclone could form at any time between July 1, 2020, and June 30, 2021, and would count towards the season total. During the season, tropical cyclones will be officially monitored by the
Fiji Meteorological Service The Fiji Meteorological Service (FMS) is a Department of the government of Fiji responsible for providing weather forecasts and is based on the grounds of Nadi Airport in Nadi. The current director of Fiji Meteorological Service is Misaeli Funaki. ...
(FMS), Australian
Bureau of Meteorology The Bureau of Meteorology (BOM or BoM) is an executive agency of the Australian Government responsible for providing weather services to Australia and surrounding areas. It was established in 1906 under the Meteorology Act, and brought together ...
(BoM), New Zealand's
MetService Meteorological Service of New Zealand Limited (MetService - Te Ratonga Tirorangi) is the national meteorological service of New Zealand. MetService was established as a state-owned enterprise in 1992. It employs about 300 staff, and its headqua ...
. The
United States Armed Forces The United States Armed Forces are the military forces of the United States. The armed forces consists of six service branches: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. The president of the United States is the ...
through the
Joint Typhoon Warning Center The Joint typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South P ...
(JTWC) will also monitor the basin and issue unofficial warnings for American interests. RSMC Nadi attaches a number and an F suffix to tropical disturbances that form in or move into the basin while the JTWC designates significant tropical cyclones with a number and a P suffix. RSMC Nadi, TCWC Wellington and TCWC Brisbane all use the
Australian Tropical Cyclone Intensity Scale Tropical cyclones are ranked on one of five tropical cyclone intensity scales, according to their maximum sustained winds and which tropical cyclone basins they are located in. Only a few scales of classifications are used officially by the mete ...
and estimate windspeeds over a period of ten minutes, while the JTWC estimated sustained winds over a 1-minute period, which are subsequently compared to the Saffir–Simpson hurricane wind scale (SSHWS). The season began with the formation of Tropical Depression 01F, over a month after the official start. Despite the slightly late start, activity picked up, with two more systems forming after. In mid-December, Severe Tropical Cyclone Yasa became the earliest category 5 severe tropical cyclone on record in the South Pacific basin. Yasa struck
Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...
, resulting in heavy damage. Severe Tropical Cyclone Ana and Tropical Cyclone Bina also affected Fiji within days of each other, resulting in heavy rains and strong winds. Tropical Cyclone Lucas crossed into the basin from the Australian region and affected the
Loyalty Islands The Loyalty Islands Province ( French ''Province des îles Loyauté'') is one of three administrative subdivisions of New Caledonia encompassing the Loyalty Island (french: Îles Loyauté) archipelago in the Pacific, which are located northeast of ...
. In early March,
Cyclone Niran Severe Tropical Cyclone Niran was a very powerful tropical cyclone that brought severe impacts to extreme Northeastern Australia and nearly made landfall in New Caledonia in February and March 2021. The sixth tropical cyclone and the second severe ...
moved into basin from the Australian region as a Category 5 severe tropical cyclone. The storm passed close to
New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...
, bringing heavy impact, before transitioning into an extratropical cyclone north of
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
. __TOC__


Seasonal forecasts

Ahead of the cyclone season formally starting, the Fiji Meteorological Service (FMS), Australian
Bureau of Meteorology The Bureau of Meteorology (BOM or BoM) is an executive agency of the Australian Government responsible for providing weather services to Australia and surrounding areas. It was established in 1906 under the Meteorology Act, and brought together ...
(BoM), New Zealand's
MetService Meteorological Service of New Zealand Limited (MetService - Te Ratonga Tirorangi) is the national meteorological service of New Zealand. MetService was established as a state-owned enterprise in 1992. It employs about 300 staff, and its headqua ...
and
National Institute of Water and Atmospheric Research The National Institute of Water and Atmospheric Research or NIWA ( mi, Taihoro Nukurangi), is a Crown Research Institute of New Zealand. Established in 1992, NIWA conducts research across a broad range of disciplines in the environmental scien ...
(NIWA) and various other Pacific Meteorological services, all contributed towards the Island Climate Update tropical cyclone outlook that was released during October 2020. The outlook took into account the ENSO neutral conditions that had been observed across the Pacific and analog seasons, that had ENSO neutral and El Nino conditions occurring during the season. The outlook called for a near-average number of tropical cyclones for the 2020–21 season, with nine to twelve named tropical cyclones, predicted to occur between 135°E and 120°W, compared to an average of just over 10. At least four of the tropical cyclones were expected to intensify further and become severe tropical cyclones, while it was noted that a Category 5 severe tropical cyclone could occur during the season. In addition to contributing towards the Island Climate Update outlook, the FMS and the BoM issued their own seasonal forecasts for the South Pacific region. The BoM issued two seasonal forecasts for the Southern Pacific Ocean, for their self-defined eastern and western regions of the South Pacific Ocean. They predicted that the Western region between 142.5°E and 165°E, had a 60% chance of seeing activity above its average of 4 tropical cyclones. The BoM also predicted that the Eastern Region between 165°E and 120°W, had a 45% chance of seeing activity above its average of 6 tropical cyclones. Within their outlook the FMS predicted that between four and six tropical cyclones would occur within the basin compared to an average of around 7. At least one of these tropical cyclones was expected to intensify further and become a Category 3 or higher severe tropical cyclone.


Seasonal summary

ImageSize = width:800 height:215 PlotArea = top:10 bottom:80 right:20 left:20 Legend = columns:3 left:30 top:58 columnwidth:270 AlignBars = early DateFormat = dd/mm/yyyy Period = from:01/12/2020 till:01/05/2021 TimeAxis = orientation:horizontal ScaleMinor = grid:black unit:month increment:1 start:01/12/2020 Colors = id:canvas value:gray(0.88) id:GP value:red id:TDi value:rgb(0,0.52,0.84) legend:Tropical_Disturbance id:TD value:rgb(0.43,0.76,0.92) legend:Tropical_Depression id:C1 value:rgb(0.30,1,1) legend:Category_1_=_63-87_km/h_(39-54_mph) id:C2 value:rgb(0.75,1,0.75) legend:Category_2_=_88-142_km/h_(55-74_mph) id:C3 value:rgb(1,0.85,0.55) legend:Category_3_=_143-158-km/h_(75-98_mph) id:C4 value:rgb(1,0.45,0.54) legend:Category_4_=_159–204_km/h_(99–127_mph) id:C5 value:rgb(0.55,0.46,0.9) legend:Category_5_=_≥205_km/h_(≥128_mph) Backgroundcolors = canvas:canvas BarData = barset:Hurricane bar:Month PlotData = barset:Hurricane width:10 align:left fontsize:S shift:(4,-4) anchor:till from:08/12/2020 till:12/12/2020 color:TD text:"01F (TD)" from:11/12/2020 till:19/12/2020 color:C5 text:" Yasa (C5)" from:11/12/2020 till:16/12/2020 color:C2 text:"Zazu (C2)" from:22/01/2021 till:26/01/2021 color:TDi text:"04F (TDi)" from:26/01/2021 till:01/02/2021 color:C3 text:" Ana (C3)" from:27/01/2021 till:28/01/2021 color:TDi text:"06F (TDi)" from:29/01/2021 till:31/01/2021 color:C1 text:"Bina (C1)" from:01/02/2021 till:03/02/2021 color:C2 text:"Lucas (C2)" barset:break from:07/02/2021 till:10/02/2021 color:C2 text:"09F (C2)" from:22/02/2021 till:23/02/2021 color:TDi text:"10F (TDi)" from:05/03/2021 till:06/03/2021 color:TD text:"11F (TD)" from:05/03/2021 till:06/03/2021 color:C5 text:" Niran (C5)" from:09/04/2021 till:11/04/2021 color:C1 text:"13F (C1)" bar:Month width:5 align:center fontsize:S shift:(0,-20) anchor:middle color:canvas from:01/12/2020 till:01/01/2021 text:December from:01/01/2021 till:01/02/2021 text:January from:01/02/2021 till:01/03/2021 text:February from:01/03/2021 till:01/04/2021 text:March from:01/04/2021 till:01/05/2021 text:April TextData = pos:(569,23) text:"(For further details, please see" pos:(713,23) text:"
scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...
)"
On December 8, a disturbance formed near
Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...
, starting the 2020–21 South Pacific Ocean cyclone season, it gradually intensified into a depression and attained a tropical storm status according to JTWC. It reached at the maximum 10 minutes sustained wind speed of and minimum pressure of . Another disturbance formed near the existing 01F and rapidly intensified into a depression. It hampered the system intensification due to a brief interaction with Tropical Depression 01F. Following the same day, another disturbance formed and intensified into a depression the next day. 01F became a remnant low and was absorbed by Tropical Depression 02F. On December 13, 15:00 UTC, 02F intensified into a Category 1 tropical cyclone, giving it the name Yasa. It quickly strengthened into a Category 5 tropical cyclone before impacting Fiji. 03F intensified into Category 1 tropical cyclone Zazu, strengthening to Category 2. Yasa became the third most intense tropical cyclone of 2020, behind only Goni and Haishen with a minimum barometric pressure of and a maximum wind speed of . Yasa caused heavy damage in and four deaths in Fiji. It then became extratropical on December 20. After all that, the basin remained quiet for a while until activity picked up in late January. Four depressions formed within a few days of each other, with two becoming named, Ana and Bina. Ana became a Category 3 tropical cyclone struck Fiji like Yasa did and caused damage in the island nation. Bina was a short-lived storm that affected Fiji and
Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...
. Then, on February 1, Lucas entered the basin form the Australian region. It peaked as a Category 2 tropical cyclone and affected the
Loyalty Islands The Loyalty Islands Province ( French ''Province des îles Loyauté'') is one of three administrative subdivisions of New Caledonia encompassing the Loyalty Island (french: Îles Loyauté) archipelago in the Pacific, which are located northeast of ...
. Afterward, another depression formed. Another pause of inactivity ensued again, with only a small disturbance forming, in late February. However, in early March, Niran entered the basin from the Australian region as a Category 5 severe tropical cyclone. It passed close to
New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...
before becoming extratropical north of
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
. The basin became quiet once again until a disturbance formed on April 9, strengthening into a depression later. Upon post-analysis data, it was updated to Category 1 tropical cyclone (Australian scale).


Systems


Tropical Depression 01F

During December 8, the FMS reported that Tropical Disturbance 01F had developed about to the northeast of Apia in Samoa. At this stage, the system had a broad low level circulation and was located within a marginal environment for further development, with warm sea surface temperatures as well as moderate levels of vertical wind shear. Over the next couple of days, the system gradually moved westwards before the FMS classified it as a tropical depression during December 11, while it was located about to the west of the Fijian Dependency of Rotuma. At 00:00 UTC on December 11, the JTWC upgraded the system to a tropical storm on the Saffir–Simpson hurricane wind scale. The depression continued to consolidate, with deep convection wrapping into the centre of the system from the northern semicircle, and by 12:00 UTC, one-minute sustained winds had increased to . A few hours later, the FMS estimated maximum 10-minute sustained winds to be at , with a minimum central
atmospheric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 7 ...
of . However, environmental conditions were only marginally conducive for intensification, with strong
vertical wind shear Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizonta ...
inhibiting further development. By 00:00 UTC on December 12, both the JTWC and the FMS reported that the shear had displaced the system's deep convection to the northeast, leaving the center of circulation fully exposed. Due to the deteriorating structure of the system, the FMS ceased advisories on Tropical Depression 01F at this time. The storm then weakened and degenerated into a low pressure system later on December 12. Because of the
Fujiwhara effect The Fujiwhara effect, sometimes referred to as the Fujiwara effect, Fujiw(h)ara interaction or binary interaction, is a phenomenon that occurs when two nearby cyclonic vortices move around each other and close the distance between the circulations ...
, the remnant was absorbed by Tropical Depression 02F shortly afterward, which would later become Severe Tropical Cyclone Yasa. 01F caused heavy rain in American Samoa, with a peak rainfall total of recorded at the
Pago Pago International Airport Pago Pago International Airport , also known as Tafuna Airport, is a public airport located 7 miles (11.3 km) southwest of the central business district of Pago Pago, in the village and plains of Tafuna on the island of Tutuila in American S ...
.


Severe Tropical Cyclone Yasa

Tropical Disturbance 02F was first noted by the FMS on December 11, while it was located about to the northeast of Port Villa in Vanuatu. Environmental conditions were very favourable for
tropical cyclogenesis Tropical cyclogenesis is the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropical cyclogenesis occurs are distinctly different from those through which temperate cyclogenesis occurs. Tropi ...
, with radial
outflow Outflow may refer to: *Capital outflow, the capital leaving a particular economy *Bipolar outflow, in astronomy, two continuous flows of gas from the poles of a star *Outflow (hydrology), the discharge of a lake or other reservoir system * Outflow ...
in the upper
troposphere The troposphere is the first and lowest layer of the atmosphere of the Earth, and contains 75% of the total mass of the planetary atmosphere, 99% of the total mass of water vapour and aerosols, and is where most weather phenomena occur. From ...
, low
vertical wind shear Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizonta ...
, and
sea surface temperature Sea surface temperature (SST), or ocean surface temperature, is the ocean temperature close to the surface. The exact meaning of ''surface'' varies according to the measurement method used, but it is between and below the sea surface. Air mass ...
s near . Convective
rainband A rainband is a cloud and precipitation structure associated with an area of rainfall which is significantly elongated. Rainbands can be stratiform or convective, and are generated by differences in temperature. When noted on weather radar ima ...
s began to develop around the system as it tracked slowly eastwards, wrapping into the low-level circulation center. At 00:00 UTC on December 12, the Fiji Meteorological Service (FMS) upgraded the system to Tropical Depression 02F and began issuing forecast track maps. At the same time, the Joint Typhoon Warning Center (JTWC) issued a
tropical cyclone formation alert A Tropical Cyclone Formation Alert (TCFA) is a bulletin released by the U.S. Navy-operated Joint Typhoon Warning Center in Honolulu, Hawaii or the Fleet Weather Center in Norfolk, Virginia, warning of the possibility of a tropical cyclone forming ...
for the system. The JTWC also noted a
Fujiwhara interaction The Fujiwhara effect, sometimes referred to as the Fujiwara effect, Fujiw(h)ara interaction or binary interaction, is a phenomenon that occurs when two nearby cyclonic vortices move around each other and close the distance between the circulations ...
with 01F, which briefly hampered the development of the system. At 15:00 UTC December 12, the JTWC determined the system had strengthened into Tropical Cyclone 05P and was now producing winds up to gale force, while it absorbed the remnant of Tropical Depression 01F. About a day later, on December 13, the FMS determined that the depression had further strengthened to Category 1 status, as convection continued wrapping into the center, with the storm acquiring the name ''Yasa''. Soon afterwards, the JTWC upgraded Yasa to a Category 1-equivalent cyclone on the
Saffir–Simpson scale The Saffir–Simpson hurricane wind scale (SSHWS) classifies hurricanes—which in the Western Hemisphere are tropical cyclones that exceed the intensities of tropical depressions and tropical storms—into five categories distinguished by ...
. The storm continued to intensify and soon became a Category 3 on the Australian scale. Just about 12 hours later on December 14, Yasa rapidly intensified to Category 4 status on the Australian scale as a defined
eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...
began to clear on infrared satellite imagery. The storm continued rapidly intensifying and strengthened to a Category 5 tropical cyclone on the Australian scale, the highest rating possible, while completing its loop, with a central pressure of 929 bar and wind speeds of 110 knots (125  mph). This was the earliest date a Category 5 South Pacific tropical cyclone formed on record and only the second Category 5 South Pacific tropical cyclone recorded in December. Yasa continued its rapid intensification trend and further intensified to the equivalent of a high-end Category 4 tropical cyclone on the
Saffir–Simpson scale The Saffir–Simpson hurricane wind scale (SSHWS) classifies hurricanes—which in the Western Hemisphere are tropical cyclones that exceed the intensities of tropical depressions and tropical storms—into five categories distinguished by ...
(SSHWS), developing a well-defined and obvious eye, while continuing to become more symmetrical. By 00:00 UTC on December 16, Yasa had intensified into a Category 5-equivalent tropical cyclone on the SSHWS, with 1-minute sustained winds of . At 18:00 UTC, Yasa's maximum 10-minute sustained winds increased to , with a minimum atmospheric pressure of 917
hPa HPA may refer to: Organizations * Harry Potter Alliance, a charity * Halifax Port Authority, Canada * Hamburg Port Authority, Germany * Hawaii Preparatory Academy, a school in Hawaii, US * Health Protection Agency, UK * Heerespersonalamt, the Ger ...
(27.08
inHg Inch of mercury (inHg and ″Hg) is a non- SI unit of measurement for pressure. It is used for barometric pressure in weather reports, refrigeration and aviation in the United States. It is the pressure exerted by a column of mercury in heigh ...
), making the system one of the most intense tropical cyclones ever recorded in the Southern Hemisphere. After making landfall on
Vanua Levu Vanua Levu (pronounced ), formerly known as Sandalwood Island, is the second largest island of Fiji. Located to the north of the larger Viti Levu, the island has an area of and a population of 135,961 . Geology Fiji lies in a tectonically ...
, Yasa moved into an area of unfavorable conditions, causing the storm to rapidly weaken, with Yasa weakening into a Category 3 severe tropical cyclone later that day. Yasa continued its weakening trend as it turned southward, dropping to Category 1 tropical cyclone status in late December 18. Late on December 19, Yasa transitioned into an
extratropical storm Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of ...
, and the FMS issued their final advisory on the storm. Afterward, Yasa's extratropical remnant moved southward and then eastward, before dissipating on December 24, to the northeast of
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
.


Tropical Cyclone Zazu

During December 11, the FMS reported that Tropical Disturbance 03F had developed about to the northeast of the island nation of
Niue Niue (, ; niu, Niuē) is an island country in the South Pacific Ocean, northeast of New Zealand. Niue's land area is about and its population, predominantly Polynesian, was about 1,600 in 2016. Niue is located in a triangle between Tong ...
. Deep convection near the system was initially only fragmented; however, environmental conditions were assessed as being conducive for development, with low
vertical wind shear Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizonta ...
, good upper-level
outflow Outflow may refer to: *Capital outflow, the capital leaving a particular economy *Bipolar outflow, in astronomy, two continuous flows of gas from the poles of a star *Outflow (hydrology), the discharge of a lake or other reservoir system * Outflow ...
and
sea surface temperature Sea surface temperature (SST), or ocean surface temperature, is the ocean temperature close to the surface. The exact meaning of ''surface'' varies according to the measurement method used, but it is between and below the sea surface. Air mass ...
s near . The system's organisation improved steadily over the next few days, and at 12:00 UTC on December 13, the Joint Typhoon Warning Center (JTWC) upgraded the depression to a tropical storm on the Saffir-Simpson hurricane wind scale. Zazu continued to strengthen even as it began
extratropical transition Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of p ...
, reaching Category 2 status on the Australian scale on December 15, despite struggling with the effects of westerly wind shear. During December 16, the system moved into MetService's area of responsibility, before they reclassified it as an extratropical low later that day. Zazu's extratropical remnant continued southward for another day, before turning eastward on December 18, and dissipating a day later. Yellow cyclone alerts (the third-highest level) were issued for the island of
Niue Niue (, ; niu, Niuē) is an island country in the South Pacific Ocean, northeast of New Zealand. Niue's land area is about and its population, predominantly Polynesian, was about 1,600 in 2016. Niue is located in a triangle between Tong ...
on December 15, while residents were taken to higher grounds by officials. Zazu brought heavy surf which severely damaged the
wharf A wharf, quay (, also ), staith, or staithe is a structure on the shore of a harbour or on the bank of a river or canal where ships may dock to load and unload cargo or passengers. Such a structure includes one or more berths (mooring locatio ...
on
Niue Niue (, ; niu, Niuē) is an island country in the South Pacific Ocean, northeast of New Zealand. Niue's land area is about and its population, predominantly Polynesian, was about 1,600 in 2016. Niue is located in a triangle between Tong ...
which was recently rebuilt while bringing rainy conditions to the island that same day. Zazu also brought wind gusts up to to the island nation of
Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...
, but no significant damage was reported.


Tropical Disturbance 04F

During January 22, the FMS reported that Tropical Disturbance 04F had developed about to the northwest of Noumea in
New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...
. At this stage, the system was poorly organised and lied under the western edge of an upper-level ridge of high pressure in a low to moderate area of vertical windshear. Early on January 27, the storm strengthened into a tropical depression. The FMS ceased advisories on the system, late on January 28.


Severe Tropical Cyclone Ana

During January 26, the FMS reported that Tropical Disturbance 05F had developed within the
South Pacific convergence zone The South Pacific Convergence Zone (SPCZ), a reverse-oriented monsoon trough, is a band of low-level convergence, cloudiness and precipitation extending from the Western Pacific Warm Pool at the maritime continent south-eastwards towards French Pol ...
about to the northeast of Port Vila in Vanuatu. During that day, the system moved eastwards and developed into a tropical depression, within an area of low to moderate vertical
wind shear Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal ...
. Over the next couple of days, the system moved eastwards and gradually developed further, as
atmospheric convection Atmospheric convection is the result of a parcel-environment instability, or temperature difference layer in the atmosphere. Different lapse rates within dry and moist air masses lead to instability. Mixing of air during the day which expands the ...
started to wrap into the systems low level circulation center. During January 29, the FMS reported that the depression had developed into a Category 1 tropical cyclone on the Australian scale and named it Ana. At this time, the system was located about to the northwest of Nadi in Fiji and had started to be steered south-southeastwards towards Fiji, by a ridge of high pressure to the northeast of the system. The United States
Joint Typhoon Warning Center The Joint typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South P ...
subsequently initiated advisories, on the newly named system and designated it as Tropical Cyclone 15P. During January 30, Ana continued to move south-southeastwards and passed through the northern
Yasawa Islands The Yasawa Group is an archipelago of about 20 volcanic islands in the Western Division of Fiji, with an approximate total area of . Geography The Yasawa volcanic group consists of six main islands and numerous smaller islets. The archip ...
into the Bligh Waters, where it became slow-moving and intensified into a category 2 tropical cyclone. The system subsequently continued to develop with an eye feature appearing on both radar and microwave imagery before it made
landfall Landfall is the event of a storm moving over land after being over water. More broadly, and in relation to human travel, it refers to 'the first land that is reached or seen at the end of a journey across the sea or through the air, or the fact ...
on
Viti Levu Viti Levu (pronounced ) is the largest island in the Republic of Fiji. It is the site of the nation's capital, Suva, and home to a large majority of Fiji's population. Geology Fiji lies in a tectonically complex area between the Australian P ...
near
Rakiraki Rakiraki () is a district in Fiji's Ra Province. It is located between Tavua and Korovou when travelling along the Kings Road, on the northern coast of Viti Levu, Fiji's largest island. At the 1996 census, the Rakiraki district had a populati ...
at around 18:00 UTC (06:00 FST, January 31). While located over Viti Levu, Ana moved south-southeastwards over the Central Division, where it passed in between
Navua Navua () is a town in Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeas ...
and Fiji's capital city:
Suva Suva () is the capital and largest city of Fiji. It is the home of the country's largest metropolitan area and serves as its major port. The city is located on the southeast coast of the island of Viti Levu, in Rewa Province, Central Divi ...
. The JTWC subsequently reported that the system had peaked with 1-minute sustained winds of , which made it equivalent to a Category 1 hurricane on the Saffir-Simpson hurricane wind scale. During January 31, Ana emerged into the Kadavu Passage and passed near or over Kadavu, before the FMS reported that the system had peaked as a Category 3 severe tropical cyclone, with 10-minute sustained winds of . During February 1, the system rapidly weakened into a subtropical low, as its low-level circulation center became exposed and moved south-eastwards into an area of high vertical wind shear. Over the next few days, Ana moved south-eastwards over the South Pacific Ocean as a subtropical low, before it was last noted during February 3.


Tropical Disturbance 06F

During January 27, the FMS reported that Tropical Disturbance 06F had developed near the Lau Island of
Nayau Nayau is an island of Fiji, a member of the Lau archipelago. Nearby cities: Suva; Nuku'Alofa; Coordinates: 17°58'39"S 179°3'13"W. Nayau, north of Lakeba Lakeba (pronounced ) is an island in Fiji’s Southern Lau Archipelago; the pr ...
, about to the east of Suva, Fiji. At this stage, the system was poorly organised and located to the south of a ridge of high pressure, in an area of moderate to high vertical wind shear. Later that day the system developed into a tropical depression and caused gale-force winds over the Lau Islands, before it was last noted by the FMS during the next day as it moved out of the tropics. Strong winds and heavy rainfall associated with the depression affected
Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...
on January 29.


Tropical Cyclone Bina

During January 29, the FMS reported that Tropical Disturbance 07F had developed about to the north-northeast of Port Vila in Vanuatu in a relatively favorable environment with warm
sea surface temperature Sea surface temperature (SST), or ocean surface temperature, is the ocean temperature close to the surface. The exact meaning of ''surface'' varies according to the measurement method used, but it is between and below the sea surface. Air mass ...
s and low
wind shear Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal ...
. On the evening of January 31, the depression intensified further to Tropical Cyclone Bina. However, Bina soon became very disorganized and was downgraded to a tropical depression on the morning of February 1. It further weakened to an area of low pressure on the same day as it became even more disorganized. Despite not being classified as a tropical cyclone at
landfall Landfall is the event of a storm moving over land after being over water. More broadly, and in relation to human travel, it refers to 'the first land that is reached or seen at the end of a journey across the sea or through the air, or the fact ...
, Bina extended the heavy rains and gale winds associated with Cyclone Ana which struck the islands hours before. The Prime Minister
Frank Bainimarama Josaia Voreqe "Frank" Bainimarama (Fijian: ʃoˈsɛia βoˈreŋɡe mbɛiniˈmarama born 27 April 1954) is a Fijian politician and former naval officer who served as the prime minister of Fiji from 2007 until 2022. A member of the FijiFirst ...
urged the public to continue being aware and be cautious of continued flash floods.


Tropical Cyclone Lucas

On the afternoon of February 1, Tropical Cyclone Lucas moved into the basin from the Australian region as a Category 2 tropical cyclone, to the northwest of
Port Vila Port Vila (french: Port-Vila), or simply Vila (; french: Vila; bi, Vila ), is the capital and largest city of Vanuatu. It is located on the island of Efate. Its population in the last census (2009) was 44,040, an increase of 35% on the pr ...
in
Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...
. Lucas maintained a steady southwestward heading during its time in the basin, and gradually weakened under increasing vertical wind shear. Lucas's LLC became exposed as it weakened to a Category 1 cyclone on the Australian scale and began to undergo subtropical transition just north of
New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...
on February 2, at which time the JTWC ceased warnings on the storm. Shortly after, Lucas made landfall in
New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...
at 18:00 UTC that day as a Category 2 tropical cyclone. In the
Loyalty Islands The Loyalty Islands Province ( French ''Province des îles Loyauté'') is one of three administrative subdivisions of New Caledonia encompassing the Loyalty Island (french: Îles Loyauté) archipelago in the Pacific, which are located northeast of ...
, numerous homes, telecommunication systems, and electrical lines were damaged. An estimated 6,338 people lost power in the country during the cyclone's passing. Drinking water was contaminated and communication was cut off for over 36 hours. A 29-year-old woman and another man drowned off the
Gold Coast Gold Coast may refer to: Places Africa * Gold Coast (region), in West Africa, which was made up of the following colonies, before being established as the independent nation of Ghana: ** Portuguese Gold Coast (Portuguese, 1482–1642) ** Dutch G ...
of
Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...
amidst dangerous swells produced by the extratropical remnants of Lucas, their bodies having been recovered on February 9.


Tropical Cyclone 09F

On February 7, a weak tropical disturbance formed near the Lau Island of Cikobia-i-Lau, to the north of
Nadi Nadi (pronounced ) is the third-largest conurbation in Fiji. It is located on the western side of the main island of Viti Levu, and had a population of 42,284 at the most recent census, in 2007. A 2012 estimate showed that the population had ...
,
Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...
. The JTWC issued a TCFA on the disturbance at 15:00 UTC the next day, designating it as ''Invest 92P''. It strengthened to a tropical depression as it tracked to the south. However, the FMS ceased their warnings on 09F as it moved out of the tropics. The JTWC on the other hand had upgraded the system to Tropical Cyclone 20P early on February 10, with 1-minute sustained winds of . However, the JTWC also issued their final warning on 09F as it accelerated south-southeastward and became extratropical.


Tropical Disturbance 10F

On February 22, a tropical disturbance formed from the
South Pacific convergence zone The South Pacific Convergence Zone (SPCZ), a reverse-oriented monsoon trough, is a band of low-level convergence, cloudiness and precipitation extending from the Western Pacific Warm Pool at the maritime continent south-eastwards towards French Pol ...
, to the northwest of
Labasa Labasa (pronounced ) is a town in Fiji with a population of 27,949 at the most recent census held in 2007. Labasa is located in Macuata Province, in the north-eastern part of the island of Vanua Levu, and is the largest town on the island. Th ...
,
Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...
. It moved to the southwest slowly under the periphery of a trough. However, the disturbance was declared a low pressure system on February 24, with the FMS issuing their final warning.


Tropical Depression 11F

On March 5, the FMS reported that Tropical Disturbance 11F had formed to the southeast of
Port Vila Port Vila (french: Port-Vila), or simply Vila (; french: Vila; bi, Vila ), is the capital and largest city of Vanuatu. It is located on the island of Efate. Its population in the last census (2009) was 44,040, an increase of 35% on the pr ...
,
Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...
. Under an unfavorable environment and the nearby
Cyclone Niran Severe Tropical Cyclone Niran was a very powerful tropical cyclone that brought severe impacts to extreme Northeastern Australia and nearly made landfall in New Caledonia in February and March 2021. The sixth tropical cyclone and the second severe ...
, the storm moved to the southeast before dissipating on the next day. Upon post-analysis data, the FMS upgraded 11F to tropical depression with 10-min winds of 35 mph.


Severe Tropical Cyclone Niran

On March 5, Severe Tropical Cyclone Niran entered the basin from the Australian region as it continued to move to the east. Maintaining its initial intensity as a Category 5 cyclone, it also became the third severe tropical cyclone of the season, alongside
Yasa Yasa was a bhikkhu during the time of Gautama Buddha. He was the sixth bhikkhu in the Buddha's sangha and was the sixth to achieve arahanthood. Yasa lived in the 6th century BCE in what is now Uttar Pradesh and Bihar in northern India. Yasa wa ...
and Ana. At that time, the storm began to weaken due to increasing wind shear and on near-midnight, it skirted the southeastern coast of
New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...
as a Category 3 severe tropical cyclone. Further weakening continued as Niran accelerated to the southeast while leaving the coast of the country, before becoming
extratropical Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of p ...
on the next day. The system continued moving southeastward for two days, before being absorbed into a larger
extratropical cyclone Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of ...
to the south on March 8. As the storm approached, New Caledonia was placed on high alert, as Niran was expected to cause severe damage in the country, especially on the main island of Grande Terre. Authorities placed the entire island nation under a Level Two Tropical Cyclone Alert late on March 5 as the storm bore down on the country.
Air Calédonie Société Calédonienne de Transports Aériens, trading as Air Calédonie, is the domestic airline of the French collectivity of New Caledonia. Its headquarters are on the grounds of Magenta Airport in the territory's capital of Nouméa, from ...
moved their entire fleet of airplanes to
Brisbane Brisbane ( ) is the capital and most populous city of the states and territories of Australia, Australian state of Queensland, and the list of cities in Australia by population, third-most populous city in Australia and Oceania, with a populati ...
, Australia, in order to protect them from the storm. Waves as high as were also expected for the western side of New Caledonia. Niran caused extensive damage in New Caledonia during its close passage. 39,000 households lost electricity in urban areas while roads quickly became impassable. Winds of up to affected portions of the country in its passage, despite the strongest portion of the storm missing the coastline. Two people were injured, including a child which was hit by shards of glass from a bay window. In the capital city of
Nouméa Nouméa () is the capital and largest city of the French special collectivity of New Caledonia and is also the largest francophone city in Oceania. It is situated on a peninsula in the south of New Caledonia's main island, Grande Terre, a ...
, several ships were forced aground on the coast. 400 people were also housed in three evacuation centers. Another estimate placed over 69,000 total customers without power in the country. Rainfall was less than anticipated, with a report of of rain falling in six hours. Vegetation and crops were damaged as well, though the true extent of damage is unknown.


Tropical Cyclone 13F

On April 8, the BoM started to monitor a tropical low in the northeastern Australian Region. The tropical low quickly moved southeastward and entered the South Pacific region, where it organized further into Tropical Depression 13F, with the JTWC designating it as Tropical Cyclone 28P. Soon after its formation, however, extratropical transition begun, and within 18 hours after its formation, the JTWC gave its last warning as it merged with a large extratropical cyclone. Upon post-analysis data, 13F was upgraded to Category 1 tropical cyclone.


Storm names

Within the South Pacific, a tropical depression is judged to have reached tropical cyclone intensity should it reach winds of , and it is evident that gales are occurring at least halfway around the center. Tropical depressions that intensify into a tropical cyclone between the Equator and 25°S and between 160°E and 120°W are named by the FMS. However, if a tropical depression reaches tropical cyclone strength to the south of 25°S between 160°E and 120°W, it will be named by MetService in conjunction with the FMS. Should a tropical cyclone move out of the basin and into the Australian region, it will retain its original name. The names that was used for 2020–21 season is listed below: If a tropical cyclone enters the South Pacific basin from the Australian region basin (west of 160°E), it will retain the name assigned to it by the
Australian Bureau of Meteorology Australian(s) may refer to: Australia * Australia, a country * Australians, citizens of the Commonwealth of Australia ** European Australians ** Anglo-Celtic Australians, Australians descended principally from British colonists ** Aboriginal Aus ...
. The following storms were named in this manner: * Lucas *
Niran Na'aran ( he, נערן), formerly known as Niran () is an Israeli settlement organized as a kibbutz in the West Bank. Located in Area C of the Jordan Valley near Jericho,


Season effects

This table lists all the storms that developed in the South Pacific to the east of 160th meridian during the 2020–21 season. It includes their intensity on the Australian tropical cyclone intensity scale, duration, name, landfalls, deaths, and damages. All meteorological data is taken from the warning centers while damage estimates are in 2021 USD. , - , 01F , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , American Samoa, Fiji , , None , , None , , , - ,
Yasa Yasa was a bhikkhu during the time of Gautama Buddha. He was the sixth bhikkhu in the Buddha's sangha and was the sixth to achieve arahanthood. Yasa lived in the 6th century BCE in what is now Uttar Pradesh and Bihar in northern India. Yasa wa ...
, , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , Vanuatu, Fiji , , $246.7 million , , 4 , , , - , Zazu , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , Samoan Islands, Tonga, Niue , , Minimal , , Unknown , , , - , 04F , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , Vanuatu , , None , , 0 , , , - , Ana , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , Fiji , , >$1 million , , 1 , , , - , 06F , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , Fiji , , None , , 0 , , , - , Bina , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , Vanuatu, Fiji , , None , , 0 , , , - , Lucas , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , Vanuatu, New Caledonia , , Unknown , , 2 , , , - , 09F , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , Wallis and Futuna, Fiji, Tonga , , None , , 0 , , , - , 10F , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , Wallis and Futuna, Tonga, Samoan Islands, Niue , , None , , 0 , , , - , 11F , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , None , , None , , 0 , , , - ,
Niran Na'aran ( he, נערן), formerly known as Niran () is an Israeli settlement organized as a kibbutz in the West Bank. Located in Area C of the Jordan Valley near Jericho,
, , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , New Caledonia , , >$200 million , , 0 , , , - , 13F , , , , bgcolor=#, , , bgcolor=#, , , bgcolor=#, , , New Caledonia , , Minimal , , 0 , ,


See also

*
Weather of 2020 The following is a list of weather events that occurred on Earth in the year 2020. Global conditions As 2020 began, sea surface temperatures were above normal in the eastern Pacific Ocean near the equator, which had the potential to develop ...
and
2021 File:2021 collage V2.png, From top left, clockwise: the James Webb Space Telescope was launched in 2021; Protesters in Yangon, Myanmar following the 2021 Myanmar coup d'état, coup d'état; A civil demonstration against the October–November 2021 ...
* List of Southern Hemisphere cyclone seasons *
Tropical cyclones in 2020 During 2020, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, 141 tropical cyclones formed in bodies of water known as tropica ...
and
2021 File:2021 collage V2.png, From top left, clockwise: the James Webb Space Telescope was launched in 2021; Protesters in Yangon, Myanmar following the 2021 Myanmar coup d'état, coup d'état; A civil demonstration against the October–November 2021 ...
*Atlantic hurricane seasons:
2020 2020 was heavily defined by the COVID-19 pandemic, which led to global Social impact of the COVID-19 pandemic, social and Economic impact of the COVID-19 pandemic, economic disruption, mass cancellations and postponements of events, COVID- ...
,
2021 File:2021 collage V2.png, From top left, clockwise: the James Webb Space Telescope was launched in 2021; Protesters in Yangon, Myanmar following the 2021 Myanmar coup d'état, coup d'état; A civil demonstration against the October–November 2021 ...
*Pacific hurricane seasons:
2020 2020 was heavily defined by the COVID-19 pandemic, which led to global Social impact of the COVID-19 pandemic, social and Economic impact of the COVID-19 pandemic, economic disruption, mass cancellations and postponements of events, COVID- ...
,
2021 File:2021 collage V2.png, From top left, clockwise: the James Webb Space Telescope was launched in 2021; Protesters in Yangon, Myanmar following the 2021 Myanmar coup d'état, coup d'état; A civil demonstration against the October–November 2021 ...
*Pacific typhoon seasons:
2020 2020 was heavily defined by the COVID-19 pandemic, which led to global Social impact of the COVID-19 pandemic, social and Economic impact of the COVID-19 pandemic, economic disruption, mass cancellations and postponements of events, COVID- ...
,
2021 File:2021 collage V2.png, From top left, clockwise: the James Webb Space Telescope was launched in 2021; Protesters in Yangon, Myanmar following the 2021 Myanmar coup d'état, coup d'état; A civil demonstration against the October–November 2021 ...
*North Indian Ocean cyclone seasons:
2020 2020 was heavily defined by the COVID-19 pandemic, which led to global Social impact of the COVID-19 pandemic, social and Economic impact of the COVID-19 pandemic, economic disruption, mass cancellations and postponements of events, COVID- ...
,
2021 File:2021 collage V2.png, From top left, clockwise: the James Webb Space Telescope was launched in 2021; Protesters in Yangon, Myanmar following the 2021 Myanmar coup d'état, coup d'état; A civil demonstration against the October–November 2021 ...
* 2020–21 South-West Indian Ocean cyclone season *
2020–21 Australian region cyclone season The 2020–21 Australian region cyclone season was a below average but very deadly season when most tropical cyclones formed in the Southern Indian Ocean and Pacific Oceans between 90°E and 160°E. It produced 8 tropical cyclones with 3 stren ...


References


External links

{{DEFAULTSORT:2020-21 South Pacific cyclone season South Pacific cyclone seasons Southern Hemisphere tropical cyclone seasons