South Pacific cyclone season 2011–2012

South Pacific cyclone season 2011–2012

All the storms of the season
Formation of the first storm	November 13, 2011
Dissolution of the last storm	April 11, 2012
Strongest storm	Jasmine - 942  hPa  ( mbar ), 100  kn  (185  km / h )  (10 minutes)
Trop. Disruptions	20th
Tropical lows	16
Tropical cyclones	3
Tropical cyclones	2
Heavy tropical cyclones	1
Total number of victims	13
Total damage	$ 17.2 million   (2011)
South Pacific cyclone season 2009-10 , 2010-11 , 2011-2012 , 2012-13 , 2013-14

The South Pacific cyclone season 2011–2012 was one of the cyclone seasons in the South Pacific with very little activity, as only three systems developed into tropical cyclones. It refers to the period of the year in which most tropical cyclones usually form in the South Pacific between 160 ° E and the date line . The cyclone season officially lasted from November 1, 2011 to April 30, 2012, but tropical systems also count towards the season if they are in the cyclone year defined by the World Meteorological Organization for the southern hemisphere between July 1, 2011 and June 30 Formed in 2012. The first disruption of the season formed on November 13, 2011, and the last system broke up on April 11, 2012.

Tropical cyclones within the South Pacific basin are monitored by the Regional Specialized Meteorological Center (RSMC), which operates the Fiji Meteorological Service in Nadi , Fiji, and a Tropical Cyclone Warning Center (TCWC) in Wellington , the Meteorological Service of New Zealand Limited . The RSMC Nadi assigns a designation consisting of the letter F and a consecutive two-digit number for all systems that arise within the South Pacific or move into this area. The United States' Joint Typhoon Warning Center (JTWC) issues unofficial storm warnings in the South Pacific; storms are identified with the letter P and a two-digit number. The JTWC storm warnings are primarily aimed at United States military facilities. RSMC Nadi and TCWC Wellington use the Australian scale, which is based on ten-minute sustained winds, while the JTWC uses one-minute winds and the Saffir-Simpson hurricane wind scale .

Season forecasts

source	season	tropical cyclones	severe tropical cyclones	Ref.
average	(1969–70 - 2010–2011)	9	-
highest activity	1997-98	16
low activity	2003-04 / 2008-09	3	0
RSMC Nadi	October 2011	5-8	4-5
NIWA	October 2011	5-8	4-5

During October 2011, both RSMC Nadi and New Zealand's National Institute of Water and Atmospheric Research (NIWA) released seasonal forecasts, which included predictions of how many tropical cyclones would form in the upcoming season. Due to a weak La Niña in the first half of the season and neutral conditions in the second half of the season, both agencies expected a below-average level of activity. The RSMC Nadi therefore predicted that 5–8 tropical cyclones would form in the basin.

Both the RSMC and the NIWA assessed the risk of a tropical cyclone occurring for the individual island groups in their forecasts. Both institutes assumed that there was a high risk for New Caledonia and Vanuatu to be hit by a cyclone; for Fiji, Tonga and the Cook Islands, this risk was assessed as moderate to high. The risk for other islands and archipelagos, such as Niue, Wallis and Futuna, Samoa, the Solomon Islands, Tuvalu and Tokelau was therefore considered to be very low to moderate. The RSMC Nadi also predicted that Vanuatu, Fiji, New Caledonia and Tonga were at moderate to high risk of being hit by a severe tropical cyclone.

Season course

Storms

Tropical disturbance 01F

Tropical disorder ( FMS )
Duration	November 13th - November 16th
intensity	Wind strength unknown, 1004 hPa

Late on November 13th, the RSMC in Nadi reported that a tropical fault had formed inside a low pressure trough about 400 km north of Suva . The following day, the system moved southeast along the trough before the convection surrounding the system decreased significantly, due to the influence of the two main islands of Fiji. Once south of the two islands, 01F moved eastward for a few days and continued to weaken. Early on November 17, the RSMC issued its final warnings about the system weakening into a depression.

Tropical Depression 02F

Tropical Depression ( FMS )
Duration	December 28th - January 1st
intensity	Wind strength unknown, 1002 hPa

Early on December 28, RSMC Nadi reported the formation of Tropical Fault 02F about 140 km southeast of Alofi on Niue . During the course of the day, the fault moved north-northwest, into an area with high vertical wind shear . On December 30th the system intensified into a tropical depression. Then the system weakened again to a glitch, which resolved on January 1st.

Tropical disturbance 03F

Tropical disorder ( FMS )
Duration	January 7th - January 8th
intensity	Wind strength unknown, 1001 hPa

On January 7, RSMC Nadi began monitoring a tropical disturbance that had formed about 150 miles southeast of Lifuka , Tonga . The disturbance persisted for the next 24 hours, with slight wind shear southeast of the center, but late the following day the RSMC reported that further development of the disturbance was no longer to be expected and issued the last warning on 03F, since during the During the day the convection in the area around the center was only irregular.

Tropical Depression 04F

Tropical Depression ( FMS )
Duration	January 8th - January 9th
intensity	Wind strength unknown, 1000 hPa

On January 8, RSMC Nadi found that Tropical Depression 04F had developed about 465 km west of Papeete on the French Polynesian island of Tahiti . 04F had an isolated, ground-level circulation center and was east of a low pressure trough and west of a strong convection area. Over the next 24 hours, the convection surrounding the system shifted increasingly far to the east of the cleared center, due to strong wind shear. Because of this, the RSMC issued the final 04F warning late on January 9th.

Tropical disturbance 05F

Tropical disorder ( FMS )
Duration	January 8th - January 10th
intensity	Wind strength unknown, 1000 hPa

Late on January 8, RSMC Nadi reported that Tropical Fault 05F was developing within a tropical low pressure trough approximately 460 km southeast of Apia , Samoa . The disturbance did not develop further during the following days, so that the RSMC Nadi issued the last warning about the system on January 10th.

Tropical Depression 06F

Tropical Depression ( FMS )
Duration	January 19 - January 25
intensity	Wind strength unknown, 1001 hPa

The RSMC Nadi reported on January 19 that a tropical disturbance had formed south of Fiji. This intensified to a tropical depression a day later, but dissolved on January 25, so the RSMC issued the final warning about the system.

Tropical Depression 07F

Tropical Depression ( FMS )
Duration	January 26th - February 2nd
intensity	30 kn (55 km / h ) (10 minutes) , 994 hPa

The RSMC Nadi reported the formation of a tropical fault near Vanuatu on January 26th . This intensified into a tropical depression on January 29th. On February 1, the Depression appeared quickly disorganized as the transition to a non-tropical system began, and the RMSC issued the final Nadi warning on 07F . On February 2, the system completed the extra-tropical transition.

Tropical Depression 08F

Tropical Depression ( FMS )
Duration	January 25th - January 28th
intensity	Wind strength unknown, 1001 hPa

On January 25, a tropical depression formed near Fiji, which resolved on January 28.

Tropical Depression 09F

Tropical Depression ( FMS )
Duration	January 30th - January 31st
intensity	30 kn (55 km / h ) (10 minutes) , 998 hPa

The RSMC noted the formation of a tropical depression about 250 km northeast of Port Vila in Vanuatu on January 30th , but the organization of the system deteriorated rapidly, so meteorologists issued the final warning on 09F on January 31st .

Tropical Depression 10F

Tropical Depression ( FMS )
Duration	February 2 - February 6
intensity	20 kn (35 km / h ) (10 minutes) , 991 hPa

On February 2, the RSMC reported to Nadi that a tropical depression had formed east of New Caledonia , but late on February 6, the system weakened so much that it was no longer classified as a tropical disturbance, so the RSMC issued its final warning published to the system.

Tropical cyclone Cyril

Tropical Category 2 Cyclone ( FMS )
Tropical storm
Duration	February 5th - February 8th
intensity	50 kn (95 km / h ) (10 minutes) , 985 hPa

On February 5, the RSMC reported to Nadi that a tropical depression had formed east of Fiji. On February 6, the system intensified further, so that the JTWC initially issued a Tropical Cyclone Forming Alert and after a few hours the system was classified as a tropical storm with the designation 11P . The RSMC Nadi assigned the name Cyril. The system was thus the first system of the season named by the Fiji Meteorological Service. Cyril pulled in a southeasterly direction and continued to gain strength, reaching Category 2 on the Australian cyclone scale. Late on February 7th, Cyril weakened back to Category 1 and moved to the area of ​​responsibility of the TCWC in Wellington, so that the RSMC Nadi issued the final warning about Cyclone Cyril. However, the system lost power and after the system weakened below the threshold of tropical disturbance, the TCWC Wellington issued the final warning on Cyril late February 8th.

Severe tropical cyclone Jasmine

Tropical Category 4 Cyclone ( FMS )
Category 4 cyclone
Duration	February 6  (from the Australian region )  - February 16
intensity	100 kn (185 km / h ) (10 minutes) , 942 hPa

On February 6th, the cyclone Jasmine, which was rapidly intensifying into a severe tropical cyclone, moved to the area of ​​responsibility of the RSMC Nadi and showed properties of an annular system. The system passed between New Caledonia and Efate . Some smaller islands belonging to New Caledonia and Vanuatu experienced strong winds and heavy rain on February 8th, including the island of Anatom . The system continued to move southeast on February 8, intensifying into a cyclone equivalent to Category 4 on the Saffir-Simpson Hurricane Wind Scale. On February 9th, Jasmine's weakening began as the cyclone began cyclic eyewall re-formation. Jasmine entered the area of ​​responsibility at TCWC Wellington late that day, where the downward trend continued. After the eyewall re-formation, Jasmine began regaining strength late on February 10th with a larger eye about 75 km in diameter. However, this intensification phase did not last long. A few days later, a high pressure area south of cyclone Jasmine pushed east. Late on February 11th, Jasmine weakened into a Category 1 cyclone and turned northeast. Early on February 12th, the cyclone came back into the responsibility of the RSMC in Nadi, so the Fiji Meteorological Service resumed issuing warnings. Two days later, the system moved further north, and Jasmine generated on to Tonga islands belonging Tongatapu and Nuku'alofa squalls, torrential rain and floods. That day, Cyclone Jasmine started executing a loop. The system moved first west and then south before swiveling southeast and following that direction until it disintegrated. Late on February 16, Jasmine weakened into a tropical disturbance due to strong wind shear and shortly afterwards changed into an extra-tropical system. The RSMC Nadi therefore issued its final warning to Jasmine. The TCWC Wellington continued the system for a few days in a south-easterly direction as tropical, but the residual low dissolved on February 19.

Tropical Depression 13F

Tropical Depression ( FMS )
Duration	February 13th - February 17th
intensity	Wind strength unknown, 1005 hPa

Early on February 14th, RSMC Nadi reported the formation of Tropical Depression 13F in an area of ​​low vertical wind shear, approximately 850 km northwest of Nouméa in New Caledonia . The system moved east-south-east for the day before changing direction the next day and slowly migrating west-south-west. The meteorologists of the Fiji Meteorological Service issued the last warning about the system on February 17th, as a development into a tropical storm was no longer expected and it had moved into the area of ​​responsibility of the TCWC in Brisbane in the Australian cyclone region.

Tropical Depression 14F

Tropical Depression ( FMS )
Duration	March 16 - March 18
intensity	Wind strength unknown, 1003 hPa

Tropical Disturbance 15F

Tropical disorder ( FMS )
Duration	March 19 - March 20
intensity	Wind strength unknown, 1004 hPa

Tropical disturbance 16F

Tropical disorder ( FMS )
Duration	March 23rd - March 27th
intensity	Wind strength unknown, 1003 hPa

Tropical Depression 17F

Tropical Depression ( FMS )
Duration	March 25th - March 31st
intensity	Wind strength unknown, 1000 hPa

Tropical Depression 18F

Tropical Depression ( FMS )
Duration	March 30th - March 31st
intensity	Wind strength unknown, 1004 hPa

Tropical cyclone Daphne

Tropical Category 2 Cyclone ( FMS )
Tropical storm
Duration	March 31st - April 3rd
intensity	50 kn (95 km / h ) (10 minutes) , 985 hPa

Tropical Depression 20F

Tropical Depression ( FMS )
Duration	April 9th ​​- April 11th
intensity	Wind strength unknown, 1009 hPa

On April 9, the RSMC reported to Nadi that Tropical Fault 20F had formed near New Caledonia. The system moved southeast and began to deepen as it passed over New Caledonia. On April 10th, the RSMC found that 20F had intensified into a tropical depression. Later that day, 20F was already at its peak. On April 11th, the system turned on a southwestern track and left the French overseas territory behind. Then the system turned east and began to weaken as moderate wind shear displaced the convection of the system east of center. The depression continued to move east, and the wind shear eroded away most of the convection of the system. Late on April 11th, the RSMC in Nadi issued its last warning about the disintegrating system.

Storm names

→ Main article : List of names of tropical cyclones

If a tropical depression has intensified within the South Pacific to such an extent that the sustained ten-minute wind speeds are at least 65 km / h and these wind speeds surround the center at least halfway, these storms are given names. If these storms intensify between the equator and 25 ° S and between 160 ° E and 120 ° W, they are named by the Regional Specialized Meteorological Center in Nadi (RSMC Nadi). If the system intensifies south of 25 ° S, the Tropical Cyclone Warning Center (TCWC Wellington) in Wellington, New Zealand assigns the name in consultation with the RSMC Nadi. The first name given in the 2011–2012 season was Cyril. Systems moving from or across the Basin to the Australian region will retain their original name. In the 2011–2012 season, this affected the severe tropical cyclone Jasmine.

Cyril Daphne Evan  (unused) Freda  (unused) Garry  (unused)

Haley  (unused) Ian  (unused) June  (unused) Kofi  (unused) Lusi  (unused)

See also

• Atlantic hurricane seasons: 2011 , 2012
• Pacific hurricane seasons: 2011 , 2012
• Pacific Typhoon Seasons: 2011 , 2012
• North Indian cyclone seasons: 2011 , 2012
• Cyclone season in the Southwest Indicator 2011–2012
• Australian cyclone season 2011–2012

Individual evidence

1. ↑ ^{a b} Tropical Cyclone Operational Plan for the Southwest Indian Ocean and the Southern Pacific Ocean ( English , PDF; 860 kB) In: RA V Tropical Cyclone Committee . World Meteorological Organization . March 10, 2009. Retrieved December 20, 2011.
2. ^ ^{A b} Regional Specialized Meteorological Center Nadi, Fiji: Tropical Disturbance Summary 2012-01-07 21z ( English ) Fiji Meteorological Service. January 7, 2012. Archived from the original on January 8, 2012. Retrieved on January 9, 2012.
3. ^ ^{A b c} Regional Specialized Meteorological Center Nadi, Fiji: Tropical Disturbance Summary 2012-01-08 23z ( English ) Fiji Meteorological Service. January 8, 2012. Archived from the original on January 8, 2012. Retrieved on January 9, 2012.
4. ↑ ^{a b} RSMC Nadi - Tropical Cyclone Center: Tropical Disturbance Summary 2012-01-09 21z ( English ) Fiji Meteorological Service. January 9, 2012. Archived from the original on January 9, 2012. Retrieved on February 19, 2012.
5. ↑ Regional Specialized Meteorological Center Nadi, Fiji: Tropical Disturbance Advisory Number A11 2012-02-01 06z ( English ) Fiji Meteorological Service. February 1, 2012. Archived from the original on February 1, 2012. Retrieved on February 1, 2012.
6. ^ Regional Specialized Meteorological Center Nadi, Fiji: Tropical Disturbance Advisory Number B3 2012-01-31 06z ( English ) Fiji Meteorological Service. January 31, 2012. Archived from the original on January 31, 2012. Retrieved on February 1, 2012.
7. ^ Regional Specialized Meteorological Center Nadi, Fiji: Tropical Disturbance Advisory Number A4 2012-02-07 15z ( English ) Fiji Meteorological Service. February 7, 2012. Archived from the original on February 7, 2012. Retrieved on February 7, 2012.
8. ↑ ^{a b} Jim Andrews: Tropical Cyclone Jasmine ( English ) In: Accuweather . February 7, 2012. Archived from the original on February 7, 2012. Retrieved on February 8, 2012.
9. ↑ ^{a b} Tropical Cyclone Jasmine's Eye Seen From Space ( English ) In: Our Amazing Planet . February 9, 2012. Archived from the original on February 9, 2012. Retrieved on February 9, 2012.
10. ^ Regional Specialized Meteorological Center Nadi, Fiji: Tropical Disturbance Advisory Number B14 2012-02-09 18z ( English ) Fiji Meteorological Service. February 9, 2012. Archived from the original on February 10, 2012. Retrieved on February 10, 2012.
11. ↑ http://weather.noaa.gov/pub/data/raw/wt/wtps12.nffn..txt ( Memento from February 12, 2012 on WebCite )
12. ↑ Flash flooding to hit Tonga ( English ) In: Asia Pacific News . Australian Broadcasting Corporation . February 16, 2012. Retrieved February 16, 2012.
13. ↑ http://gwydir.demon.co.uk/advisories/WTPS12-NFFN_201202161200.htm ( Memento from February 17, 2012 on WebCite )
14. ↑ ^{a b} RSMC Nadi - Tropical Cyclone Center: Tropical Disturbance Summary 2012-02-14 00z ( English ) Fiji Meteorological Service. February 14, 2012. Archived from the original on February 14, 2012. Retrieved on February 26, 2012.
15. ↑ RSMC Nadi - Tropical Cyclone Center: Tropical Disturbance Summary 2012-02-14 21z ( English ) Fiji Meteorological Service. February 14, 2012. Archived from the original on February 14, 2012. Retrieved on February 19, 2012.
16. ↑ RSMC Nadi - Tropical Cyclone Center: Tropical Disturbance Summary 2012-02-15 09z ( English ) Fiji Meteorological Service. February 15, 2012. Archived from the original on February 16, 2012. Retrieved on February 19, 2012.
17. ↑ RSMC Nadi - Tropical Cyclone Center: Tropical Disturbance Summary 2012-02-17 23z ( English ) Fiji Meteorological Service. February 17, 2012. Archived from the original on February 18, 2012. Retrieved on February 26, 2012.
18. ↑ http://gwydir.demon.co.uk/advisories/WWPS21-NFFN_201204101200.htm ( Memento from April 11, 2012 on WebCite )
19. ↑ http://gwydir.demon.co.uk/advisories/WWPS21-NFFN_201204102100.htm ( Memento from April 11, 2012 on WebCite )
20. ↑ http://gwydir.demon.co.uk/advisories/WWPS21-NFFN_201204110900.htm ( Memento from April 11, 2012 on WebCite )

Web links

• Joint Typhoon Warning Center (JTWC) .
• Fiji Meteorological Service (RSMC Nadi) .
• Meteorological Service of New Zealand, Ltd. (TCWC Wellington) .
• World Meteorological Organization