Tropical Storm Sonamu (2013)

Last updated
Map key
  Tropical depression (≤38 mph, ≤62 km/h)
  Tropical storm (39–73 mph, 63–118 km/h)
  Category 1 (74–95 mph, 119–153 km/h)
  Category 2 (96–110 mph, 154–177 km/h)
  Category 3 (111–129 mph, 178–208 km/h)
  Category 4 (130–156 mph, 209–251 km/h)
  Category 5 (≥157 mph, ≥252 km/h)
  Unknown
Storm type
Disc Plain black.svg Tropical cyclone
Solid black.svg Subtropical cyclone
ArrowUp.svg Extratropical cyclone, remnant low, tropical disturbance, or monsoon depression

On January 1, the Japan Meteorological Agency (JMA) first noted that a tropical depression formed at about 1,090 km (680 mi) southwest of Guam. [2] The next day, the US-based Joint Typhoon Warning Center (JTWC) also noted an area of convection persisted east of Mindanao. [3] The depression tracked west-northwest and made landfall in Davao Oriental at 12 a.m. PST January 3 (16:00 UTC January 2). [4] [nb 1] Despite this, deep convection maintained, which prompted the JTWC to issue a Tropical Cyclone Formation Alert (TCFA). [5] The depression emerged into the Sulu Sea on January 3 and continued to develop. Although situated in a marginal environment with warm waters of 28–30 °C (82–86 °F), strong diffluence and moderate wind shear, the depression continued to develop as a central dense overcast (CDO) formed over the center, and deep convection nearby increased. [6] As such, the JMA upgraded the system to a tropical storm at 12:00 and assigned the name Sonamu. [2] At that time, Sonamu was the fourth earliest named storm in the calendic year since reliable records begins in 1951. [7] The JTWC classified the system as a tropical depression three hours later and assigned it as 01W, [8] The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) also initiated warnings and assigned the local name Auring. [9] At 4 a.m. PST January 4 (20:00 UTC January 3), Sonamu made landfall at the southern tip of Palawan, near Bataraza, with winds of 65 km/h (40 mph). [10]

Tropical Depression Sonamu approaching Mindanao on January 2 JMA TD Jan 2 2013 0532Z.jpg
Tropical Depression Sonamu approaching Mindanao on January 2

On January 4, the JTWC upgraded it to a tropical storm as it tracked westward and emerged into the South China Sea. [11] The PAGASA issued the final advisory as Sonamu exited the Philippine Area of Responsibility (PAR). [12] Environmental conditions remained marginally favourable, as the center became partly exposed due to strong wind shear. Nonetheless, the JMA further upgrade Sonamu to a severe tropical storm early on January 5, as it turned west-southwest under the influence of a subtropical ridge to its north. Concurrently, Sonamu attained its peak intensity with peak winds of 95 km/h (60 mph). [2] [13] Good poleward outflow offset the effects of wind shear, and the convection was burst over the southwestern quadrant of Sonamu. [14] Wind shear along with dry air from the northeast monsoon continued to affect Sonamu, and the center became ragged and exposed with deep convection sheared to the northwest, [15] which prompted the JMA to downgraded it to a tropical storm on January 7 [2] Despite unfavourable condition, deep convection continued to burst over the southern part of Sonamu, which slowed down its weakening trend. [16] However, the burst was short-lived, as Sonamu moved to water with only 26 °C (79 °F), and the center soon exposed again. Situated between two subtropical ridges, the steering current became weak, which caused Soamu to slow down and began to drift southeastward. [17] The JTWC downgraded Sonamu to a tropical depression at 15:00 UTC. [18] At 00:00 UTC January 8, the JMA also downgraded Sonamu to a tropical depression, [2] though the JTWC upgraded it to a tropical storm at 03:00 UTC, as a CDO was formed again and obscured the center. [19] Nonetheless, the center soon became ill-definied, which prompted the JTWC to downgraded Sonamu to a tropical depression again just six hours later. [20] The JTWC soon issued the final warnings, but the JMA still maintained Sonamu at tropical depression status, as isolated convection continued to burst to the west of the center. [2] [21] Sonamu dissipated on January 10 just off the coast of Sarawak, about 45 km (28 mi) north of Mukah. [2]

Preparations and impact

Shortly after being classified as tropical depression, the PAGASA issued the PSWS #1 for Lanao Del Sur, provinces in Northern Mindanao, Zamboanga Peninsula, Negros Island Region and Palawan. [9] Late on January 3, the PAGASA raised the PSWS of southern Palawan to #2 as Sonamu strengthened to a tropical storm, while the remaining part of the province was still under PSWS #1. [22] All the PSWS were cancelled on the next day as Sonamu exited the PAR and moved away from the country. [12]

Sonamu brought rainfalls to Mindanao and Visayas. Authorities warned for potential flooding and landslides that affected the region. [4] 1,405 people were evacuated in Valencia, Bukidnon, Dipolog and Palawan in advance of the storm. [23] Another 500 people were evacuated in Quezon, Bukidnon. [24] Hundreds of people were stranded, as watercraft services in western Mindanao were suspended. Two houses in Roxas, Palawan were destroyed. [25] Domestic flights in Pagadian were cancelled. Sea vessels were not allowed to entered the open waters in the Zamboanga peninsula. In Kapalong, Davao del Norte, a teenager boy was swept away by a raving waters and was declared missing. [26] In Dumaguete, a ship went aground after winds of 34 km/h (21 mph) broke the mooring ties. 228 people on the ship were rescued. [27] Two people were killed by Sonamu. A man died in Rizal, Palawan after being hit by a fallen tree. [24] Another person were drowned in Bataraza. [1] The storm also injured 12 others, all in Palawan. 10,597 people were affected by Sonamu. 185 houses were damaged during the storm, in which 63 of them were destroyed. [1] However, overall effects across the country was minimal.

As Sonamu approached the coast of Malaysia, the country felt waves of up to 2.2 m (7.2 ft) from the storm. [28]

Retirement

In February 2014, the Typhoon Committee announced that the name Sonamu would be removed from the naming list, because the pronunciation of the name is similar to "tsunami", which triggered fear in Malaysia. [29] In 2015, the name was replaced by Jongdari which is the Korean name of skylark. [30]

See also

Notes

  1. At that time, the PAGASA considered Sonamu as a low-pressure area, though the JMA classified it as a tropical depression.

References

  1. 1 2 3 4 del Rosario, Eduardo D. (2013). Final Report re Effects of Tropical Storm AURING (PDF) (Report). National Disaster Risk Reduction and Management Council. Archived (PDF) from the original on March 5, 2016. Retrieved March 4, 2016.
  2. 1 2 3 4 5 6 7 Severe Tropical Storm Sonamu (RSMC Tropical Cyclone Best Track). Japan Meteorological Agenc. January 25, 2013. Archived from the original on September 27, 2013. Retrieved October 1, 2013.
  3. "Significant Tropical Weather Advisory for the Western and South Pacific Oceans January 2, 2013 13z". Joint Typhoon Warning Center. January 2, 2013. Archived from the original on September 24, 2013. Retrieved October 1, 2013.
  4. 1 2 Yap, DJ (January 4, 2013). "'Auring' dumps heavy rains in Northern Mindanao, Visayas". INQUIRER.net. Archived from the original on January 7, 2013. Retrieved January 5, 2013.
  5. "Tropical Cyclone Formation Alert: January 2, 2013 21z". Joint Typhoon Warning Center. January 2, 2013. Archived from the original on June 24, 2012. Retrieved October 1, 2013.
  6. "Significant Tropical Weather Advisory for the Western and South Pacific Oceans January 3, 2013 06z". Joint Typhoon Warning Center. January 3, 2013. Archived from the original on September 14, 2013. Retrieved October 1, 2013.
  7. フィリピン沖で台風1号 史上4番目の早さ (in Japanese). The Nikkei. January 3, 2013. Archived from the original on January 6, 2013. Retrieved January 4, 2013.
  8. "Prognostic Reasoning for Tropical Depression 01W Warning Nr 01". Joint Typhoon Warning Center. January 3, 2013. Archived from the original on June 24, 2012. Retrieved October 1, 2013.
  9. 1 2 "Tropical Depression "Auring" January 3, 2013 03z" (Tropical Cyclone Alert). Philippine Atmospheric, Geophysical and Astronomical Services Administration. January 3, 2013. Archived from the original on January 3, 2013. Retrieved October 1, 2013.
  10. "'Auring' makes landfall in southern Palawan". INQUIRER.net. January 4, 2013. Archived from the original on January 5, 2013. Retrieved January 5, 2013.
  11. "Prognostic Reasoning for Tropical Storm 01W (Sonamu) Warning Nr 03". Joint Typhoon Warning Center. January 4, 2013. Archived from the original on January 4, 2013. Retrieved October 1, 2013.
  12. 1 2 "Tropical Storm "Auring" January 4, 2013 09z" (Tropical Cyclone Alert). Philippine Atmospheric, Geophysical and Astronomical Services Administration. January 4, 2013. Archived from the original on January 5, 2013. Retrieved October 1, 2013.
  13. "Prognostic Reasoning for Tropical Storm 01W (Sonamu) Warning Nr 08". Joint Typhoon Warning Center. January 5, 2013. Archived from the original on January 5, 2013. Retrieved October 1, 2013.
  14. "Prognostic Reasoning for Tropical Storm 01W (Sonamu) Warning Nr 10". Joint Typhoon Warning Center. January 5, 2013. Archived from the original on January 6, 2013. Retrieved October 1, 2013.
  15. "Prognostic Reasoning for Tropical Storm 01W (Sonamu) Warning Nr 12". Joint Typhoon Warning Center. January 5, 2013. Archived from the original on January 7, 2013. Retrieved October 1, 2013.
  16. "Prognostic Reasoning for Tropical Storm 01W (Sonamu) Warning Nr 15". Joint Typhoon Warning Center. January 7, 2013. Archived from the original on January 7, 2013. Retrieved October 1, 2013.
  17. "Prognostic Reasoning for Tropical Storm 01W (Sonamu) Warning Nr 16". Joint Typhoon Warning Center. January 7, 2013. Archived from the original on January 8, 2013. Retrieved October 1, 2013.
  18. "Prognostic Reasoning for Tropical Depression 01W (Sonamu) Warning Nr 17". Joint Typhoon Warning Center. January 7, 2013. Archived from the original on January 8, 2013. Retrieved October 1, 2013.
  19. "Prognostic Reasoning for Tropical Storm 01W (Sonamu) Warning Nr 19". Joint Typhoon Warning Center. January 8, 2013. Archived from the original on January 8, 2013. Retrieved October 1, 2013.
  20. "Prognostic Reasoning for Tropical Depression 01W (Sonamu) Warning Nr 20". Joint Typhoon Warning Center. January 8, 2013. Archived from the original on January 8, 2013. Retrieved October 1, 2013.
  21. "Prognostic Reasoning for Tropical Depression 01W (Sonamu) Warning Nr 21". Joint Typhoon Warning Center. January 8, 2013. Archived from the original on January 9, 2013. Retrieved October 1, 2013.
  22. "Tropical Storm "Auring" January 3, 2013 15z" (Tropical Cyclone Alert). Philippine Atmospheric, Geophysical and Astronomical Services Administration. January 3, 2013. Archived from the original on January 3, 2013. Retrieved October 1, 2013.
  23. "Over 1,400 evacuated as 'Auring' heads out of PH". INQUIRER.net. January 4, 2013. Archived from the original on January 7, 2013. Retrieved January 5, 2013.
  24. 1 2 "'Auring' leaves 1 dead, hundreds evacuated". SunStar. January 5, 2013. Archived from the original on March 19, 2025. Retrieved January 6, 2013.
  25. Ong, Ghio; Flores, Helen (January 4, 2013). "'Auring' to bring rains to Palawan". The Philippine Star. Archived from the original on January 6, 2013. Retrieved January 5, 2013.
  26. Lim, Frinston; Alipala, Julie S. (January 3, 2013). "Domestic flights in Pagadian City cancelled due to 'Auring'". INQUIRER.net. Archived from the original on January 6, 2013. Retrieved January 5, 2013.
  27. "Boy swept away by river; 228 survive as ship runs aground due to 'Auring'". INQUIRER.net. January 3, 2013. Archived from the original on April 27, 2015. Retrieved January 4, 2013.
  28. Chang, Nursalleh. "Impact of Tropical Cyclones "Malaysia's Experience"" (PDF). www.typhooncommittee.org. Retrieved 2025-02-16.
  29. "Retirement of Name from the List of Names of Tropical Cyclones for the Typhoon Committee Region" (PDF). Typhoon Committee. February 5, 2014. Archived (PDF) from the original on February 22, 2014. Retrieved February 22, 2014.
  30. "Replacement Name of SONAMU in the Tropical Cyclone Name List" (PDF). Typhoon Committee. January 21, 2015. Retrieved January 22, 2015.
Severe Tropical Storm Sonamu (Auring)
Sonamu Jan 5 2013 0610Z.jpg
Sonamu at peak intensity southeast of Vietnam on January 5