Tropical Cyclone Grant was a tropical cyclone that affected Queensland and the Northern Territory in late December 2011 and early January 2012.

Cyclone Grant
Category 2 tropical cyclone (Aus scale)
Tropical storm (SSHWS)
Cyclone Grant near its peak intensity on 25 December
Formed21 December 2011
Dissipated2 January 2012
Highest winds10-minute sustained: 100 km/h (65 mph)
1-minute sustained: 110 km/h (70 mph)
Lowest pressure978 hPa (mbar); 28.88 inHg
Areas affectedNorthern Territory, Queensland
Part of the 2011–12 Australian region cyclone season

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

On 21 December, the United States Joint Typhoon Warning Center and the Tropical Cyclone Warning Centre in Darwin, Australia, began monitoring an area of low pressure that had developed about 9,462 km (5,879 mi) to the northeast of Darwin.[1][2]

Tropical Low 04U developed into a Category 1 tropical cyclone on the morning of 25 December and moved slowly towards the Cobourg Peninsula.[3] The system reached Category 2 strength in the afternoon of 25 December.[4] In the evening of 28 December the system, downgraded to a tropical low, moved back onto the waters of the Gulf of Carpentaria.[5] The system continued to move eastward across the Cape York Peninsula and into the Coral Sea, even as the storm weakened, until Grant underwent an extratropical transition on 2 January 2012. Later on the same day, the extratropical remnant of Grant dissipated.


Preparations and impact edit

Northern Territory edit

A gale warning was issued for Darwin and the Tiwi Islands on 24 December.[6] The system intensified on 25 December, reaching Category 2 status in the afternoon,[7] and a cyclone watch was declared between Dundee Beach and Nhulunbuy, with a cyclone warning issued for areas between Cape Fourcroy and Milingimbi including the Tiwi Islands.[8] The system crossed Van Diemen Gulf and made a second landfall east of Point Stuart in the early morning of 26 December. Shortly thereafter the cyclone was downgraded to Category 1,[9] and by that afternoon it was downgraded to a tropical low as it passed Jabiru in Kakadu National Park.[10] Jabiru Airport had received 71.0 mm (2.80 in) of rain by 9:00am on 26 December.[11][12] On 27 December the system was moving slowly south-east across Arnhem Land,[13] causing heavy rainfall. Ediths Fall Ridge recorded 385.0 mm (15.16 in) of rainfall, which produced damaging flooding.[14] A cyclone watch was issued on 27 December from Nhulunbuy to Numbalwar, including Groote Eylandt.[15]

Flooding associated with the system in the Katherine area cut off the Stuart Highway, washed cars off bridges and derailed a train.[15] The Adelaide–Darwin railway was severely damaged by the derailment of the Genesee & Wyoming freight train. The Ghan was forced to stop with 200 passengers in Katherine.[16] One week after the cyclone had passed freight companies were poised to raise transportation costs as shipping to Darwin would need to be done by road.[17] The railway between Katherine and Darwin would be out of service until the end of January 2012.[18]

On 28 December the system moved eastward, bringing with it heavy rainfall to the Roper-McArthur River districts.[19]

Queensland edit

A cyclone watch was issued for Queensland for coastal areas from Thursday Island to Gilbert River Mouth[19] but was later cancelled when the system did not re-intensify to Category 1 strength. Late on 29 December the system as a tropical monsoon low was northwest of Pormpuraaw on the Cape York Peninsula[20] before making landfall in the early morning of 30 December south of Wiepa[21] near the aboriginal community of Aurukun.[22] A severe weather warning was issued for the Peninsula, North Tropical Coast and Gulf Country districts.[23] Later on 30 December the monsoon low passed Coen and out into the waters of the Coral Sea.

References edit

  1. ^ Unattributed (2011-12-21). "Significant tropical weather advisory for the Western and South Pacific ocean 2011-12-21 06z". Joint Typhoon Warning Center. United States Navy. Archived from the original on December 21, 2011. Retrieved 2011-12-28.
  2. ^ Unattributed (2011-12-21). "Tropical Cyclone Technical Bulletin: Australia - Northern Region 2011-12-21 06z". Darwin Tropical Cyclone Warning Centre. Bureau of Meteorology. Archived from the original on December 21, 2011. Retrieved 2011-12-28.
  3. ^ "TC Track". BOM. 25 December 2011. Archived from the original on 7 January 2012. Retrieved 25 December 2011.
  4. ^ "Cyclone moves on after whipping remote island". Archived from the original on 2014-01-02. Retrieved 2011-12-29.
  5. ^ "TROPICAL CYCLONE ADVICE NUMBER 39 (04U)". Tropical Cyclone Warning Centre, Darwin. Archived from the original on 6 September 2011. Retrieved 28 December 2011.
  6. ^ Partenza, Nathan (24 December 2011). "Darwin braces itself on Tracy anniversary as threat of holiday cyclone increases". The Age. Retrieved 24 December 2011.
  7. ^ Peddie, Clair (25 December 2011). "Top End bunkers down for cyclone". The Advertiser. Retrieved 25 December 2011.
  8. ^ "Nervous wait as NT cyclone picks its path". Archived from the original on 2014-01-02. Retrieved 2011-12-29.
  9. ^ "Cyclone updates: Boxing Day". NT News. 26 December 2011. Archived from the original on 15 March 2012. Retrieved 26 December 2011.
  10. ^ Bevege, Allison (26 December 2011). "Cyclone Grant is officially dead". NT News. Retrieved 26 December 2011.[permanent dead link]
  11. ^ "Latest Weather Observations for Jabiru (Issued at 3:05 pm CST Monday 26 December 2011)". BOM. 26 December 2011. Retrieved 26 December 2011. 26/09:00am 71.0mm
  12. ^ Wood, David (27 December 2011). "More rain at the MCG". NT News. Retrieved 27 December 2011.[permanent dead link]
  13. ^ Betts, Alyssa (27 December 2011). "Storm likely to get its puff back". NT News. Retrieved 27 December 2011.[permanent dead link]
  14. ^ "Cyclone Grant likely to reform over Gulf". ABC. 27 December 2011. Retrieved 27 December 2011.
  15. ^ a b "Flood chaos: rolling updates here". NT News. 27 December 2011. Archived from the original on 19 January 2012. Retrieved 27 December 2011.
  16. ^ Conlon, Thomas; Betts, Alyssa (27 December 2011). "Northern Territory cyclone floods derail train, cut nation in two". The Advertiser. Retrieved 27 December 2011.
  17. ^ Betts, Alyssa (4 January 2012). "Freight costs to soar after train crash". NT News. Retrieved 4 January 2012.
  18. ^ Booth, Meredith (4 January 2011). "Railway repairs expected late January". The Advertiser. Archived from the original on 14 January 2012. Retrieved 13 January 2011.
  19. ^ a b "Grant heads east to become a cyclone again". NT News. 28 December 2011. Retrieved 28 December 2011.[permanent dead link]
  20. ^ "TROPICAL CYCLONE FORECAST TRACK MAP Ex-Tropical Cyclone Grant Tropical Low 04U (11:17 pm EST 2011-12-29)". Tropical Cyclone Warning Centre, Darwin. Archived from the original on 29 December 2011. Retrieved 29 December 2011.
  21. ^ "TROPICAL CYCLONE FORECAST TRACK MAP Ex-Tropical Cyclone Grant Tropical Low 04U (4:33 am EST 2011-12-30)". Tropical Cyclone Warning Centre, Darwin. Archived from the original on 29 December 2011. Retrieved 29 December 2011.
  22. ^ "TROPICAL CYCLONE FORECAST TRACK MAP Ex-Tropical Cyclone Grant Tropical Low 04U (8:25 am EST 2011-12-30)". Tropical Cyclone Warning Centre, Darwin. Archived from the original on 21 June 2022. Retrieved 29 December 2011.
  23. ^ White, Tarina (30 December 2011). "Severe weather warning current for Cape York communities". The Cairns Post. Archived from the original on 3 February 2016. Retrieved 30 December 2011.

External links edit