Tropical Cyclone Pam
Category 2 tropical cyclone (Aus scale)
Category 1 tropical cyclone (SSHWS)
Cyclone Pam near its peak intensity
FormedDecember 5, 1997
DissipatedDecember 14, 1997
(Extratropical after December 10, 1997)
Highest winds10-minute sustained: 110 km/h (70 mph)
1-minute sustained: 120 km/h (75 mph)
Lowest pressure986 hPa (mbar); 29.12 inHg
Fatalities0
Areas affectedCook Islands
Part of the 1997–98 South Pacific cyclone season

Cyclone Pam threatened the southern Cook Islands in December 1997. A tropical depression developed December 6. The system developed slowly while it drifted to the south-southeast. Forming south of Typhoon Paka, Pam steadily intesifed and moved close to Suwarrow and later passed east of Palmerston Island and peaked in intensity on December 8, though the storm's minimum pressure was not recorded until much later. The cyclone passed by Rarotonga early on December 9. Pam slowly weakened and was no longer a tropical cyclone by December 10. Damage on the island was relatively minor though heavy rains and gale-force winds were recorded. Subsequently, 400 people were evacuated.

Meteorological history edit

 
Map plotting the storm's track and intensity, according to the Saffir–Simpson scale
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
  Extratropical cyclone, remnant low, tropical disturbance, or monsoon depression

Towards the end of November 1997, a westerly wind burst, occurred near the equator, about 2000 km (1245 mi) to the southwest of Hawaii.[1] This wind burst led to the development of two twin tropical disturbances, to the east of the International Dateline on either side of the equator.[1][2] During December 2, the system in the Northern Hemisphere was designated as a tropical depression and eventually developed into Typhoon Paka.[1] During December 5, the Fiji Meteorological Service started to monitor the Southern Hemisphere disturbance as a tropical depression, while it was located about 785 km (490 mi) to the northeast of American Samoa and about 2,100 km (1,305 mi) to the southeast of Paka.[3][4] Later that day, the Naval Pacific Meteorology and Oceanography Center (NPMOC) intiated advisories on the system and classified it as Tropical Cyclone 07P, after the system had become better organized.[5] The FMS subsequently reported early the next day that the depression had developed into a Category 1 tropical cyclone on the Australian tropical cyclone intensity scale and named it Pam.[3][4]

After it was named the system continued to slowly drift towards the south-southeast, before it started to move quicker later that day as it passed near the Cook Islands of Suwarrow.[3][4] As the system passed near Suwarrow, the NPMOC reported that Pam had reached its peak intensity with 1-minute sustained wind speeds of 120 km/h (75 mph), which made it equivalent to a category 1 hurricane on the Saffir–Simpson hurricane wind scale.[6] Over the next couple of days the system moved southwards before the FMS reported during December 8, that Pam had peaked as a category 3 severe tropical cyclone with 10-minute sustained wind-speeds of 120 km/h (75 mph).[3][7] However, during the systems post analysis, RSMC Nadi reduced these winds slightly to 110 km/h (70 mph) which made Pam a category 2 tropical cyclone, rather than a category 3 severe tropical cyclone on the Australian scale.[7][8] During December 8, the system passed about 140 km (85 mi) to the east of Palmerston Island, before it passed about 75 km (45 mi) to the southwest of Rarotonga early the next day. During December 9, Pam started to rapidly weaken as it transitioned into an extra-tropical cyclone, while RSMC Nadi reported during the next day that the system had degenerated into depression.[3][9] Over the next few days the system continued to move southeastwards, before it was last noted during December 14, while located to the west of Chile.[8]

Preparations and impact edit

Cyclone Pam was the third tropical cyclone to affect the Cook Islands during the 1997-98 season, after Severe Tropical Cyclones Martin and Osea affected the island nation during November 1997.[4][10] Ahead of the system gale warnings were issued, for various islands in both the Northern and Southern Cook Islands.[10] On the island of Aitutaki machinery and equipment was cleared from the seafront, while tourists were evacuated to Rarotonga.[11]

Rarotonga recorded winds of 44 mph (71 km/h) and gusts of 74 mph (119 km/h). A total of 149 mm (5.9 in) of rain fell on the island during a six-hour period. Damage on the island was minimal, limited from downed power lines or fallen trees. A few houses lost their roofs and low-lying roads sustained flooding[12] due to both heavy rains and rough seas.[13] Although 400 people had to be evacuated due to coastal flooding, damage was reduced because of careful precaution prior to the storm's arrival.[14] While southeast of Mangaia, winds of 30 mph (50 km/h) were measured, along with a pressure of 996 mbar (29.4 inHg).[12]

Prior to the arrival of Pam on Aitutaki Island, residents were confident that the storm would pass without serious problems.[15] Rarotonga recorded winds of 44 mph (71 km/h) and gusts of 74 mph (119 km/h). A total of 149 mm (5.9 in) of rain fell on the island during a six-hour period. Damage on the island was minimal, limited from downed power lines or fallen trees. A few houses lost their roofs and low-lying roads sustained flooding[12] due to both heavy rains and rough seas.[4] Although 400 people had to be evacuated due to coastal flooding, damage was reduced because of careful precaution prior to the storm's arrival.[14] While southeast of Mangaia, winds of 30 mph (50 km/h) were measured, along with a pressure of 996 mbar (29.4 inHg).[12]

As it weakened Pam threatened French Polynesia's Austral Islands but caused no damage.[16]

See also edit

References edit

  1. ^ a b c "3. Summary of Western North Pacific and North Indian Ocean Tropical Cyclones: Super Typhoon Paka (05C)". Annual Tropical Cyclone Report: 1997 (PDF). United States Joint Typhoon Warning Center. 1998. pp. 120–128. Retrieved August 14, 2018.
  2. ^ Chappel, Lori-Carmen; Bate, Peter W (June 2, 2000). "The South Pacific and Southeast Indian Ocean Tropical Cyclone Season 1997–98" (PDF). Australian Meteorological Magazine. 49. Australian Bureau of Meteorology: 121–138. Archived from the original on February 22, 2014. Retrieved July 23, 2013.
  3. ^ a b c d e Padgett, Gary. "Monthly Global Tropical Cyclone Summary December 1997". Archived from the original on February 22, 2014. Retrieved February 22, 2014.
  4. ^ a b c d e RSMC Nadi - Tropical Cyclone Center. Tropical Cyclone Season Summary 1997–98 (PDF) (Report). Fiji Meteorological Service. Archived from the original on August 1, 2010. Retrieved August 14, 2018.
  5. ^ "Tropical Cyclone 07P Warning 1 December 6, 1997 21z". United States Joint Typhoon Warning Center. Archived from the original on February 15, 2014. Retrieved August 14, 2018.
  6. ^ Joint Typhoon Warning Center. "Tropical Cyclone 07P (Pam) best track analysis". United States Navy, United States Air Force. Retrieved February 23, 2014.
  7. ^ a b Padgett, Gary. "Monthly Global Tropical Cyclone Tracks December 1997". Archived from the original on February 23, 2014.
  8. ^ a b "1997 Tropical Cyclone Pam (1997336S09195)". International Best Track Archive for Climate Stewardship. Retrieved October 9, 2019.
  9. ^ Joint Typhoon Warning Center. "Tropical Cyclone 07P (Pam) Warning 9 December 9, 1997 21z". United States Navy, United States Air Force. Archived from the original on February 15, 2014. Retrieved February 23, 2014.
  10. ^ a b "Cyclone Pam forms over Cook Islands". Agence France Presse. December 6, 1997.  – via Lexis Nexis (subscription required)
  11. ^ "Rarotonga battens down for Cyclone Pam". Agence France Presse. December 7, 1997.  – via Lexis Nexis (subscription required)
  12. ^ a b c d Cite error: The named reference GP was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference FMS was invoked but never defined (see the help page).
  14. ^ a b "Cyclone Pam leaves Rarotonga, no casualties reported". New Zealand International. BBC News. December 9, 1997. Retrieved July 23, 2012.
  15. ^ Cite error: The named reference PacificIslanders1997 was invoked but never defined (see the help page).
  16. ^ Laurent, Victoire; Varney, Patrick. Historique des Cyclones de Polynesie Francaise [History of Cyclones in French Polynesia] (in French). Meteo France. pp. 143–150. ISBN 978-2-9522946-1-4.

External links edit