Northern Territory wet season, October to April 2014-15: Warmer than normal

Summary

Following a drier than normal Build-up period, December and January rainfall was very much above average for the Northern Territory. Alice Springs Airport received 190 mm of rainfall in the second week of January. However, the wet weather didn't last and the final three months of the season experienced generally average to below average rainfall. The wet period in December and January was enough that, overall, the season ended with the Territory measuring 23.6 mm above the long-term average rainfall (mean = 501.6 mm).

On average, temperatures were 0.5 °C above normal for the season. This included a few periods of very hot weather in December across the north coast and in March and early April around the Gulf of Carpentaria.

  • 0.5 degrees warmer than normal for the NT
  • Monsoon onset at Darwin on 31 December 2014
  • Wet start to the Year for Alice Springs, followed by a prolonged dry period
  • Two tropical cyclones crossed the NT coastline
    • Lam, 20 February 2015
    • Nathan, 22 March 2015

Seasonal detail

The Build-Up months of October and November saw very much below average rainfall for the Territory. Large-scale climate drivers included a border-line El Niño in the central Pacific Ocean that reached its peak intensity for only a few weeks in October. With below normal rainfall also came hot days and warm nights across the Territory, especially in November. November 2014 was the 4th hottest on record for the Territory as a whole, and Alice Springs Airport measured its hottest November day on record.

A large part of the Territory, including the Top End, experienced a run of very high minimum temperatures during the second and third week of December. Darwin Airport tied its previous highest wet season daily minimum temperature record on 17 December when the overnight low was 29.7 °C. By the end of December the wet season rainfall finally arrived, but it wasn't from the long-awaited monsoon. Late in the month a mid-latitude trough pushed northward across most of the Territory bringing over 100 mm of rainfall to Barkly and Victoria River regions of the Territory.

Late in the day on 31 December, 2014, a wall of dark, ominous rain cloud rolled across the north coast near Darwin. This marked the onset of the north Australian monsoon at Darwin and across the western Top End. Daily rainfall totals around the Darwin area on 1 January include 119 mm at Darwin Airport, 162 mm at Darwin Botanic Gardens, and 136 mm at Channel Point. Heavy rainfall continued throughout the first two weeks of January.

Severe tropical cyclone Lam was the first cyclone for the 2014-15 cyclone season in the northern region, and the first severe cyclone to cross the Northern Territory coast for nearly a decade. Lam crossed the mainland coast around 2:00 am (local time) on Friday 20 February as a category 4 severe tropical cyclone, about 15 km northeast of Ramingining, and 20 km southeast of Milingimbi. Tropical cyclone Lam brought heavy rainfall to eastern Arnhem Land; Gove Airport and the Alcan Minesite both reported more than 500 mm of rainfall and three sites, including Nhulunbuy, set new daily rainfall records as outer rain bands of the cyclone pushed over the land.

About a month after Lam struck the north coast, a second severe tropical cyclone crossed the Gulf of Carpentaria toward the NT. Tropical cyclone Nathan first crossed the NT coastline about 40 km south of Nhulunbuy at around 9 am (local time) on Sunday 22 March. Nathan maintained intensity as it crossed the Gove Peninsula and then returned to sea near Arnhem Bay. It passed over Elcho Island around 7 pm on Sunday 22 March. Nathan made its third and final landfall on a remote area between Maningrida and Goulburn Island around 6:30 am on Tuesday 24 March. Tropical Cyclone Nathan and its remnant tropical depression brought heavy rainfall and flooding to many parts of the Top End. The highest 24 hour rainfall totals included 261 mm at Fanny Creek, 208 mm at Alcan Mine on the Gove Peninsula, 215 mm at Dorisvale and 208 mm at Snowdrop Creek in the Waterhouse River catchment.

Most locations that were not impacted by these two tropical cyclones received average to below average rainfall for February and March. Alice Springs Airport did not measure any rainfall for February and March. High pressure and mostly cloudless skies contributed to high temperatures across the territory. Hot weather began in the southern regions of the NT and gradually pushed northward to the Gulf of Carpentaria region. Borroloola Airport, in the Gulf region, was the hottest location in the NT this season with a seasonal mean daily maximum temperature of 39.9 °C, and set new maximum temperature records in March and April. By the end of April the Northern Territory had begun a transition into a dry season weather pattern. The coolest day of the season coincided with the last day of the season, with a few minimum temperature records set on the morning of 30 April.

Further information

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Extremes in October to April 2014-15
Hottest day 44.9 °C at Alice Springs Airport on 13 Nov 2014
Warmest days on average 37.7 °C at McArthur River Mine Airport
Coolest days on average 31.2 °C at McCluer Island
Coldest day 17.8 °C at Arltunga on 20 Apr 2015
Coldest night1.5 °C at Kulgera on 30 Apr 2015
Coolest nights on average17.9 °C at Alice Springs Airport
Warmest nights on average 26.6 °C at McCluer Island
Warmest night 31.0 °C at Tennant Creek Airport on 20 Nov 2014
Warmest on average overall30.7 °C at McArthur River Mine Airport
Coolest on average overall25.9 °C at Alice Springs Airport
Wettest overall 1832.6 mm at Territory Wildlife Park
Driest overall 88.9 mm at Curtin Springs
Wettest day 260.8 mm at Fanny Creek on 25 Mar 2015
Strongest wind gust 174 km/h at Ngayawili on 19 Feb 2015

Maps
Observed Anomaly Decile rank
Total
rainfall
Map of Rainfall totals Map of Rainfall Anomaly Map of Rainfall Decile

Click on a map to show it full size in a pop-up window

Month by month
Rainfall rank Maximum temperature rank Minimum temperature rank
October 2014: Wet season starts with below average rainfall
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
November 2014: Hot days and warm nights across the Territory
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
December 2014: A cool, wet end to a hot, dry month
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
January 2015: Monsoon arrives to Top End
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
February 2015: tropical cyclone brings heavy rain to northeast, dry elsewhere
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
March 2015: hot, dry conditions; Nathan crosses Top End coast
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
April 2015: Hot start to an overall cool month
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
Rainfall rank Maximum temperature rank Minimum temperature rank

 


Record lowest October to April total rainfall
New record
(mm)
Old
record
Years of
record
Average for
October to April
Centre Island 399.2 533.6 in 1985 43 1064.2

Lowest October to April total rainfall for at least 20 years
Observed
(mm)
Most recent
lower
Years since
lower
Average for
October to April
Humpty Doo Collard Road 1325.7 1190.8 in 1991* 20 1813.6
McMinns Lagoon 1371.9 1191.4 in 1991* 20 1825.9

* note: there are gaps in the historical record at this site, so it is possible a lower value has gone unreported.




Record highest October to April temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Mango Farm 41.5 on 1 Nov 2014 = 41.5 on 9 Oct 2013 35 34.8
Pirlangimpi Airport 38.6 on 1 Nov 2014 37.7 on 10 Oct 2013 35 32.5



Record highest October to April mean daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Centre Island 34.6 34.4 in 2012 39 33.4
Mango Farm 35.9 35.7 in 2004 33 34.8
Pirlangimpi Airport 34.2 33.5 in 2002 29 32.5



Record highest October to April daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Darwin Airport 29.7 on 17 Dec 2014 = 29.7 on 10 Dec 2009 75 24.8



Record lowest October to April temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Daly Waters Airstrip 8.4 on 17 Oct 2014 9.1 on 27 Apr 2008 46 22.7
Kulgera 1.5 on 30 Apr 2015 2.5 on 30 Apr 1986 35 18.4



Lowest October to April mean daily minimum temperature for at least 20 years
Observed
(°C)
Most recent
lower
Years since
lower
Average for
October to April
Daly Waters Airstrip 21.5 21.4 in 1945* 37 22.7
Gove Airport 23.3 =23.3 in 1991 23 23.7

* note: there are gaps in the historical record at this site, so it is possible a lower value has gone unreported.




Record highest October to April mean temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Pirlangimpi Airport 29.2 = 29.2 in 2002 28 28.3

Highest October to April mean temperature for at least 20 years
Observed
(°C)
Most recent
higher
Years since
higher
Average for
October to April
Centre Island 30.5 30.6 in 1987* 26 29.8

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported.




Summary statistics for October to April 2014-15
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
October
to April
2014-15
Diff
from
average
Highest for
October
to April
2014-15
Mean for
October
to April
2014-15
Diff
from
average
Lowest for
October
to April
2014-15
Total for
October
to April
2014-15
Average
for
October
to April
Rank of
October
to April
2014-15
Fraction of
October
to April
average
Darwin-Daly (district 14GA)
Batchelor Airport 34.7 +0.6 39.9 23 Nov 2014 23.6 +0.2 16.6 28 Apr 2015 1073.0 1557.1 low 69%
Black Point 32.3 +0.3 35.7 16 Oct 2014     21.3 27 Oct 2014 1158.4 1203.5 average 96%
Central Arnhem Plateau 33.8   38.8 29 Oct 2014 22.7   15.9 17 Oct 2014 95.2
Charles Point 32.0   34.3 19 Dec 2014 25.6   21.9 28 Feb 2015 1267.0
Darwin Airport 33.2 +0.8 36.1 17 Oct 2014 25.0 +0.2 20.7 27 Apr 2015 1380.6 1685.4 low 82%
Delamere Weapons Range 36.2 +0.9 41.5 30 Oct 2014 23.7 +0.1 14.7 28 Apr 2015 843.0 882.4 average 96%
Douglas River 35.9 +0.9 41.5 18 Nov 2014 23.1 +0.1 14.2 28 Apr 2015 918.2 1273.9 low 72%
Dum In Mirrie Airstrip 32.7 +0.5 35.2 10 Apr 2015 25.5 +0.1 20.4 27 Apr 2015 1653.6 1745.2 average 95%
Jabiru Airport 35.8 +0.9 41.6 29 Oct 2014 24.5 +0.1 19.5 3 Oct 2014 1116.4 1530.9 low 73%
Katherine Country Club 36.4   41.4 21 Nov 2014 23.7   14.6 27 Apr 2015 837.0
Mango Farm 35.9 +1.1 41.5 1 Nov 2014 23.0 -0.2 15.5 27 Apr 2015 1333.5 1388.2 average 96%
McCluer Island 31.2 -0.1 34.8 20 Dec 2014 26.6 +0.1 22.1 18 Feb 2015 878.4 1122.0 low 78%
Middle Point 35.5 +0.9 40.1 3 Nov 2014 23.1 -0.4 16.3 27 Apr 2015 1131.8 1374.0 average 82%
Murganella Airstrip 33.7   38.2 16 Dec 2014 23.2   17.1 17 Oct 2014 974.0
Noonamah Airstrip 34.8   38.9 28 Oct 2014 24.4   17.7 27 Apr 2015 1259.8
Oenpelli Airport 35.2   40.7 23 Nov 2014 24.2   18.1 3 Oct 2014 1155.0
Pirlangimpi Airport 34.2 +1.7 38.6 1 Nov 2014 24.2 +0.2 19.6 3 Oct 2014 1538.8 1946.2 low 79%
Point Fawcett 32.8 +0.6 35.7 17 Oct 2014 24.6 -0.3 18.6 3 Oct 2014
Point Stuart 33.3   36.3 15 Dec 2014 24.5   19.6 3 Oct 2014 1142.2
Port Keats Airport 33.9 +0.4 38.3 14 Mar 2015 24.5 +0.1 17.2 17 Oct 2014 1326.8 1184.9 high 112%
Tindal RAAF 36.1 +0.9 41.4 1 Nov 2014 23.4 -0.3 13.7 27 Apr 2015 949.4 1053.4 average 90%
Arnhem (district 14BC)
Cape Wessel 32.9   36.7 31 Dec 2014 25.9   21.4 17 Feb 2015 1150.6 1040.1 average 111%
Gove Airport 32.4 +0.5 37.4 13 Dec 2014 23.3 -0.4 17.7 7 Oct 2014 1700.6 1306.8 high 130%
Groote Eylandt Airport 33.9 +0.6 38.6 15 Dec 2014 23.5 -0.1 13.2 17 Oct 2014 705.4 1321.5 v low 53%
Milingimbi Airport 33.1 +0.3 38.7 12 Mar 2015 24.8 -0.1 20.2 18 Oct 2014 1241.0 1022.2 high 121%
Warruwi Airport 32.5 +0.2 36.0 20 Dec 2014 25.7 +0.1 21.2 14 Mar 2015 1105.6 1128.6 average 98%
Roper-Mcarthur (district 14DE)
Bulman 36.5   41.7 29 Oct 2014 23.2   14.8 18 Oct 2014 749.6
Centre Island 34.6 +1.2 39.9 1 Feb 2015 26.4 +0.1 21.1 28 Apr 2015 399.2 1064.2 lowest 38%
Daly Waters Airstrip 36.9 +1.0 42.2 21 Nov 2014 21.5 -1.2 8.4 17 Oct 2014 636.4 654.5 average 97%
McArthur River Mine Airport 37.7 +1.2 42.1 17 Nov 2014 23.8 +0.3 11.8 28 Apr 2015 673.4 763.5 average 88%
Ngukurr Airport 37.4   42.6 17 Dec 2014 23.9   12.6 27 Apr 2015 717.0
Victoria (district 14F)
Lajamanu Airport 37.3 +0.9 44.0 20 Nov 2014 22.2 0.0 9.6 17 Oct 2014 494.4 490.1 average 101%
Victoria River Downs 37.6 +1.2 43.0 20 Nov 2014 23.6 +0.1 9.5 27 Apr 2015 637.9 642.1 average 99%
Barkly (district 15A)
Brunette Downs 37.0 +0.6 43.5 20 Nov 2014 22.8 +0.1 11.0 28 Apr 2015 518.0 394.5 high 131%
Tennant Creek Airport 35.7 +0.5 42.6 20 Nov 2014 23.7 +0.4 13.1 26 Apr 2015 482.3 442.1 average 109%
Alice Springs (district 15B)
Alice Springs Airport 34.0 +0.8 44.9 13 Nov 2014 18.0 +0.1 3.9 28 Apr 2015 251.0 218.1 high 115%
Arltunga 33.2 +0.3 42.7 15 Dec 2014 18.4 0.0 3.4 16 Oct 2014 315.0 238.6 high 132%
Curtin Springs 35.8 +1.6 43.9 14 Dec 2014 19.8 +1.4 5.4 25 Apr 2015 88.9 171.6 average 52%
Jervois 35.7 +0.4 44.0 19 Mar 2015 20.7 +1.5 7.6 16 Oct 2014 176.4 233.8 average 75%
Kulgera     42.5 2 Jan 2015 19.5 +1.1 4.6 15 Oct 2014
Rabbit Flat 37.5 +0.4 44.2 3 Dec 2014 20.7 -0.7 6.7 17 Oct 2014 344.0 454.0 average 76%
Territory Grape Farm 35.2 +0.6 42.1 18 Mar 2015 19.2 +0.1 6.9 16 Oct 2014 318.0 243.9 high 130%
Walungurru Airport 37.3 +0.4 44.9 7 Dec 2014 23.7 +0.2 12.0 26 Apr 2015 260.8 235.9 average 111%
Yulara Airport 36.0 +1.4 44.0 14 Dec 2014 19.8 +0.9 4.4 25 Apr 2015 90.0 221.5 low 41%

Notes

A Seasonal Climate Summary is prepared to list the main features of the weather in Northern Territory using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

A Climate Summary is generally published on the first working day of each month.

This statement has been prepared based on information available at 11 am on Friday 1 May 2015. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages for individual sites are long-term means based on observations from all available years of record, which vary widely from site to site. They are not shown for sites with less than 10 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average rain.

The Rank indicates how rainfall this time compares with the climate record for the site, based on the decile ranking (very low rainfall is in decile 1, low in decile 2 or 3, average in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a percentage of the long-term mean.

The ACORN-SAT dataset is used for temperature area averages.

Further information

Media
(03) 9669 4057
Enquiries