Tuesday, 3 May 2011 - Seasonal Climate Summary for Northern Territory - Product code IDCKGC22R0
Northern Territory Wet Season 2010-11: One for the record books
With a strong La Niña enhancing Northern Territory rainfall, and the added precipitation from Tropical Cyclone Carlos, the 2010/2011 wet season is one for the record books. Many rainfall records were broken across the Territory as well as several temperature records.
Three stations exceed 3 metres of rain
Prior to this year, only one station has ever surpassed the three-metre mark during a wet season, anywhere in the Northern Territory - when Pirlangimpi recorded 3048.6mm during the 1998/99 wet season. We now have three extra stations in this category, including a new NT wet season rainfall record. The three-metre club includes Karama* with 3016.2 mm, Wagait Beach with 3142.4 mm and Leanyer* is the new NT record holder with 3165.1 mm. On 16 February the rain gauges at Karama* and Leanyer* overflowed due to the extreme nature of the rainfall during Carlos. Consequently, these rainfall totals will be an underestimate of the true amount.
Darwin Airport breaks multiple rainfall records
In the 24 hour period to 9 am on 16 February, Darwin Airport recorded 367.6 mm of rain. The previous highest 24 hour rainfall for Darwin Airport was recorded on the 3rd of January 1997, when Tropical Cyclone Rachel brought 290.4 mm of rain. The 3-day total (15 to 17 February 2011) was 684.8 mm, breaking the previous 3-day record set between 8 and 10 December 1998, when Tropical Cyclone Thelma brought 462.0 mm of rain (see Special Climate Statement 29). The monthly rainfall total for February at Darwin Airport was 1110.2 mm, becoming the wettest of any month on record, passing the March 1977 total of 1013.6 mm.
On the morning of 4 March the rain gauge reading was only 15.4 mm, but this was enough to bring the wet season total to 2511.2 mm and passing the wet season record of 2499.4 mm set in the 1997/1998 wet season. By the end of the wet season Darwin Airport had received 2918.4 mm of rainfall in 147 rain days.
Strong La Niña enhances rainfall
Historically, La Niña brings above average rainfall to Northern Australia and this year has been no exception. This years La Niña episode in tropical Pacific Ocean has compared with 1998 and 1974 in both strength and influence on the Top End weather. The most notable aspect of this La Niña has been a very strong atmospheric component. Southern Oscillation Index (SOI) values have been at record highs for most of this wet season, which corresponds with low pressure anomalies and enhanced thunderstorm activity over Darwin. The moderate to strong oceanic component of this La Nina event produced warmer than normal sea surface temperatures (SSTs) around Northern Australia, which also enhanced rainfall in the region. From October through April, La Niña was the strongest contributor to this season’s large rainfall total.
TC Carlos forms over Darwin
TC Carlos formed over the Beagle Gulf early on 16 February and moved very slowly southeast over Darwin and surrounding rural area. This contributed further rainfall to the already wet condititons. TC Carlos was downgraded to a tropical low at 6:30 am CST on 17 February, near Batchelor. Ex-TC Carlos then tracked southwards over the western Top End reaching the WA/NT border on 19 February. Very heavy rainfall associated with TC Carlos broke many rainfall records in the region. The heavy rain had a major impact on Darwin and surrounding areas, causing widespread flooding of low lying areas, inundating many houses and damaging roads and properties. Flooding of coastal areas was exacerbated by some of the largest astronomical tides of the year.
Squally winds with gusts reaching 98 km/h lashed the Darwin area during the night of the 15th and again on the 16th, felling trees, cutting roads, power lines and damaging properties. Most government departments, schools and businesses were closed for two days during the event. Darwin Airport was also closed during the worst weather conditions on 16 February. Ex-TC Carlos caused widespread flooding elsewhere in the Darwin-Daly District, including a major flood in the Daly River, inundating the community of Nauiyu about 150 km south of Darwin.
With nearly 472 mm above the wet season average, this wet season ranked 3rd wettest for the Northern Territory. Nearly every rainfall recording station in the NT measured either very much above average or highest on record this wet season. Some sites, including Darwin Airport, Adelaide River Post Office, Litchfield and Yirrkala Tropical Gardens, had their highest total October to April rainfall on record. Gove Airport, Tennant Creek Airport, Port Keats Aero, Jabiru Airport, and the Katherine Aviation Museum all measured their 2nd wettest wet season on record.
The wettest overall was Leanyer* with 3165.1 mm, followed by Wagait Beach with 3142.4 mm, followed by Karama* with 3016.2 mm. The driest overall was Curtin Springs with 244.7 mm. The wettest single day was at Darwin Airport with 367.6 mm on 16 Feb 2011.
The average daily maximum temperature for the NT during the 2010/2011 wet season was 33.0 C. This is 2.01 C below the wet season normal and ranks as the 3rd coolest wet season on record behind the 1973/1974 and 1975/1976 wet seasons. Batchelor Aero and Bradshaw are the only locations that had their coldest October to April day (lowest daily maximum temperature) on record. Seventeen sites had their lowest October to April mean daily maximum temperature on record, including the Katherine Aviation Museum and the Tindal RAAF which both had a mean daily maximum temperature of 33.6 C. The mean daily maximum temperature at Darwin Airport from October 2010 to April 2011 was 31.8 C, which is the lowest for this period since the 1956/57 wet season when the mean daily maximum temperature was 31.7 C (the average for this period is 32.4 C).
Even with the low average daily maximum temperature for the season, some high temperature records were broken. For Example, on 27 January, Yulara broke its highest temperature record when it reached a daytime maximum temperature of 46.3 °C, only to break this record again the following day with 46.4 °C. This new record falls just 1.9 °C shy of the Northern Territory maximum temperature record. Yulara recorded its hottest month on record in January with an average maximum temperature of 40.9 °C, which surpasses the previous record of 40.8 °C set in February 2007. Furthermore, Yulara measured 17 consecutive days above 40 °C during January, including 11 consecutive days above 42 °C which are both record longest hot spells of that magnitude for the site. The dates of this hot spell were from the 14 January to the 30 January, inclusive.
The hottest days in the NT were at Yulara Aero as mentioned above, followed by Walungurru with 46.2 °C on 28 Jan 2011. The coldest days in the NT were all on 15 Oct 2010 when the maximum temperature at Kulgera reached only 16.6 °C , at Arltunga the daily maximum was 17.2 °C and Alice Springs Airport had 17.6 °C. Kulgera had another cold day with 17.6 °C on 16 Oct 2010.
The warmest days on average were at Rabbit Flat with 35.3 °C, followed by McArthur River Mine and Timber Creek with 34.7 °C, and then Kidman Springs with 34.5 °C. The coolest days on average were at Arltunga with 30.2 °C, followed by Alice Springs Airport with 31.0 °C, followed by Channel Point, Gove Airport and Point Fawcett, all with 31.4 °C.
The average daily minimum temperatures around the Territory for the wet season were near average to slightly above average across the Top End, and below average to very much below average across the Alice Springs District. The average daily minimum temperature for the NT this wet season was 22.1 C which is 1.0 C below normal.
The coldest nights were recorded at Arltunga with 2.0 °C on 12 Apr 2011, followed by 3.8 °C on 25 Apr 2011, and then 4.4 °C on 19 Apr 2011. It is no surprise then that the coolest nights on average durring the wet season were at Arltunga with 16.1 °C. The next coolest nights were at Alice Springs Airport with 16.6 °C followed by Kulgera with 17.2 °C.
The warmest night was recorded at Papunya with 31.6 °C on 28 Jan 2011, followed by Walungurru with 30.9 °C also on 28 Jan 2011. The warmest nights on average were at Centre Island with 25.7 °C, followed by Warruwi with 25.3 °C.Lajamanu and Borroloola both tied their lowest October to April mean daily minimum temperature on record with 21.4 °C and 22.8 °C respectively. Darwin Airport with 24.3 °C and Tennant Creek Airport with 21.8 °C both recorded their lowest October to April mean daily minimum temperature since 1975.
The strongest wind gust was at Daly Waters with 98 km/h on 16 Nov 2010. Darwin Airport also experienced a wind gust of 98 km/h on 15 Feb 2011 associated with pre-TC Carlos. The next highest gusts were at Walungurru with 96 km/h on 28 Jan 2011, followed by North East Island with 94 km/h on 21 Jan 2011.
The Madden-Julian Oscillation (MJO) played a surprisingly minor role in this wet season's rainfall. The pattern of the oscillation was somewhat broken and erratic, and even when the MJO showed signs of a strong burst its effects were seemingly dwarfed by the strong La Nina.
|Extremes in October to April 2010-11|
46.4 °C at Yulara Aero on 28 Jan 2011
|Warmest days on average||
35.3 °C at Rabbit Flat
|Coolest days on average||
30.3 °C at Arltunga
16.6 °C at Kulgera on 15 Oct 2010
2.0 °C at Arltunga on 12 Apr 2011
|Coolest nights on average||16.1 °C at Arltunga|
|Warmest nights on average||25.7 °C at Centre Island|
|Warmest night||31.6 °C at Papunya on 28 Jan 2011|
|Warmest on average overall|| 29.3 °C at Ngukurr
|Coolest on average overall||
23.2 °C at Arltunga
3165.1 mm at Leanyer*
|Driest overall||244.7 mm at Curtin Springs|
|Wettest day||367.6 mm at Darwin Airport on 16 Feb 2011|
|Highest wind gust||
98 km/h at Daly Waters on 16 Nov 2010
98 km/h at Darwin Airport on 15 Feb 2011
* Rain gauge overflowed on 16 February
|Record highest total October to April rainfall|
for October to April 2010-11 (mm)
for October to April
October to April
|Darwin Airport||2926.8||2499.4||in 1997/1998||69||1666.2|
|Helen Springs||1034.9||846.6||in 1973/1974||56||401.7|
|Darwin Botanic Gardens*||2602.0||2419.0||in 1998/1999||48||1680.7|
|Adelaide River Post Office||2359.0||1926.0||in 2005/2005||34||1427.5|
|Darwin River Dam||2688.2||2231.6||in 1998/1999||35||1563.6|
|Mango Farm||2519.4||1803.7||in 2005/2006||26||1375.8|
|Channel Island||2945.3||2639.0||in 1996/1997||26||1612.0|
|Keep River Rangers||1417.3||1213.5||in 1988/1989||23||809.3|
|Stokes Hill||2522.2||1956.3||in 1976/1977||14||1422.1|
|Elizabeth Valley||2715.6||2309.6||in 1996/1997||14||1654.0|
|Yirrkala Tropical Gardens||2228.0||1680.4||in 1999/2000||11||1164.7|
|CSIRO Berrimah||2886.3||2528.6||in 1994/1995||10||2005.1|
|Pine Creek Council||2036.6||1833.2||in 2005/2006||10||1440.8|
|Wagait Beach||3142.4||2324.6||in 1997/1998||10||1784.3|
* Rain gauge overflowed on 16 February
|Record lowest October to April daily maximum temperature|
Lowest daily maximum
in October to April 2010-11 (°C)
for October to April
October to April
|Batchelor Aero||23.9||on 16 Feb 2011||24.8||on 4 Mar 2007||11||34.2|
|Record lowest October to April mean daily maximum temperature|
Mean daily maximum
for October to April 2010-11 (°C)
for October to April
October to April
|Brunette Downs||33.7||33.9||in 2000/2001||38||36.5|
|Victoria River Downs||34.1||34.8||in 2000/2001||34||36.5|
|Daly Waters AWS||33.7||34.2||in 2000/2001||38||36.0|
|Timber Creek||34.7||35.5||in 2000/2001||29||36.6|
|McArthur River Mine||34.6||35.2||in 1978/1979||17||36.6|
|Katherine Aviation Museum||33.6||34.5||in 2000/2001||23||35.5|
|Tindal RAAF||33.6||33.9||in 2000/2001||19||35.1|
|Douglas River||33.4||34.0||in 20052006||13||35.0|
|Lajamanu||34.2||= 34.2||in 1973/1974||14||36.5|
|Delamere Weapons Range||33.4||34.0||in 1998/1999||12||35.5|
|Kidman Springs||34.5||35.6||in 1999/2000||11||36.8|
|Batchelor Aero||32.5||33.1||in 1999/2000||11||34.2|
|Pine Creek Council||32.7||33.6||in 2000/2001||10||34.5|
|Record lowest October to April mean daily minimum temperature|
Mean daily minimum
for October to April 2010-11 (°C)
for October to April
October to April
|Borroloola||22.8||= 22.8||in 2006/2007||12||23.4|
|Lajamanu||21.4||= 21.4||in 2000/2001||13||22.2|
|Dum In Mirrie||25.0||= 25.0||in 2007/2008||11||25.5|
|Pine Creek Council||23.2||= 23.2||in 2007/2008||10||23.7|
|Summary statistics for October to April 2010-11|
|Darwin-Daly (district 14GA)|
|Batchelor Aero||32.5||-1.7||38.3||2 Oct 2010||23.4||0.0||15.1||20 Apr 2011||2355.6||1511.3||highest||156%|
|Channel Point||31.4||-0.7||34.5||30 Nov 2010||24.3||-0.3||18.4||20 Apr 2011||2141.2||1759.7||high||122%|
|Darwin Airport||31.8||-0.6||36.5||24 Oct 2010||24.3||-0.5||19.1||21 Apr 2011||2926.8||1666.2||highest||176%|
|Delamere Weapons Range||33.4||-2.1||40.0||4 Oct 2010||23.2||-0.4||16.9||29 Apr 2011||1346.4||861.8||high||156%|
|Douglas River||33.4||-1.6||39.7||4 Oct 2010||23.0||0.0||13.9||20 Apr 2011|
|Dum In Mirrie||31.7||-0.5||36.5||2 Oct 2010||25.0||-0.5||19.3||20 Apr 2011||2231.8||1755.7||v high||127%|
|Jabiru Airport||33.7||-1.2||38.9||4 Oct 2010||24.3||-0.1||19.7||28 Apr 2011||2422.6||1505.2||v high||161%|
|Katherine Aviation Museum||33.6||-1.9||39.2||6 Dec 2010||23.1||-0.5||13.7||20 Apr 2011||1651.9||1102.7||v high||150%|
|Middle Point||33.4||38.1||3 Oct 2010||23.4||16.3||20 Apr 2011||2286.0|
|Noonamah||33.4||38.1||4 Oct 2010||23.5||16.9||20 Apr 2011||2667.4|
|Pine Creek Council||32.7||-1.8||38.5||4 Oct 2010||23.2||-0.5||17.2||19 Apr 2011||2036.6||1440.8||highest||141%|
|Point Fawcett||31.4||-0.8||33.9||8 Dec 2010||24.4||-0.6||16.5||21 Apr 2011||2894.4||1431.7||highest||202%|
|Port Keats Aero||32.6||-1.0||38.0||2 Oct 2010||24.1||-0.4||15.3||20 Apr 2011||1956.8||1062.4||v high||184%|
|Tindal RAAF||33.6||-1.5||39.3||6 Dec 2010||23.2||-0.5||14.3||20 Apr 2011||1264.0||1064.3||high||119%|
|Arnhem (district 14BC)|
|Gove Airport||31.4||-0.5||34.6||1 Dec 2010||23.9||+0.2||20.3||19 Apr 2011||2135.8||1286.4||v high||166%|
|Groote Eylandt Airport||32.5||-0.9||36.1||5 Dec 2010||23.6||+0.1||16.1||19 Apr 2011||1553.4||1354.2||high||115%|
|Maningrida Aero||32.0||36.4||6 Nov 2010||24.2||20.7||3 Nov 2010||2489.0|
|Ngayawili||31.8||-0.3||35.6||1 Dec 2010||24.7||+0.1||21.0||5 Nov 2010||1546.4||1514.0||average||102%|
|Warruwi||31.8||-0.4||35.4||6 Dec 2010||25.3||-0.3||22.2||16 Feb 2011||1576.6||1125.5||v high||140%|
|Roper-Mcarthur (district 14DE)|
|Borroloola||33.9||-1.2||40.5||5 Dec 2010||22.8||-0.6||13.5||19 Apr 2011||1375.4||908.8||high||151%|
|Bulman||33.7||40.2||5 Dec 2010||23.2||15.6||19 Apr 2011||1807.4|
|Centre Island||32.4||-1.0||37.4||14 Dec 2010||25.7||-0.6||21.8||16 Oct 2010||1839.4||1006.7||v high||183%|
|Daly Waters||33.7||-2.3||40.1||25 Oct 2010||21.9||-0.9||11.7||20 Apr 2011||1132.8||636.5||v high||178%|
|Larrimah||33.8||-1.9||40.1||25 Nov 2010||22.4||-0.7||12.0||19 Apr 2011||1319.6||837.8||v high||158%|
|McArthur River Mine||34.6||-2.0||40.7||5 Dec 2010||23.4||0.0||14.9||19 Apr 2011||1462.2||727.0||v high||201%|
|Ngukurr||34.4||-1.8||40.9||5 Dec 2010||24.1||0.0||17.2||19 Apr 2011||1395.0||744.6||v high||187%|
|Wollogorang||33.7||-1.9||39.4||25 Oct 2010||22.3||-0.3||12.3||17 Oct 2010||1111.3||934.3||average||119%|
|Victoria (district 14F)|
|Kidman Springs||34.5||-2.3||41.6||24 Nov 2010||23.5||-0.4||12.4||19 Apr 2011||981.6||731.9||high||134%|
|Lajamanu||34.2||-2.3||42.6||30 Jan 2011||21.4||-0.8||9.7||19 Apr 2011||927.8||474.8||v high||195%|
|Timber Creek||34.7||-1.9||41.5||24 Nov 2010||23.7||-0.5||13.8||19 Apr 2011||1499.1||943.9||v high||159%|
|Victoria River Downs||34.1||-2.4||40.9||4 Oct 2010||22.9||-0.6||11.9||19 Apr 2011||1164.5||636.0||v high||183%|
|Barkly (district 15A)|
|Brunette Downs||33.7||-2.8||41.0||15 Dec 2010||21.9||-0.8||11.1||16 Oct 2010||808.4||389.2||v high||208%|
|Tennant Creek Airport||32.8||-2.5||41.1||27 Jan 2011||21.8||-1.6||12.2||16 Oct 2010||843.6||431.5||v high||196%|
|Alice Springs (district 15B)|
|Alice Springs Airport||31.0||-2.2||43.0||27 Jan 2011||16.6||-1.3||4.7||1 Nov 2010||492.0||215.9||v high||228%|
|Arltunga||30.3||40.2||27 Jan 2011||16.1||2.0||12 Apr 2011||713.6||234.0||highest||305%|
|Curtin Springs||33.1||-1.1||45.5||28 Jan 2011||18.1||-0.2||6.0||16 Oct 2010||244.7||166.9||high||147%|
|Kulgera||31.4||-1.6||44.9||28 Jan 2011||17.3||-1.1||4.5||11 Apr 2011||337.6||192.0||high||176%|
|Rabbit Flat||35.3||-2.0||44.1||30 Jan 2011||20.7||-0.8||9.2||24 Apr 2011||719.2||442.6||high||162%|
|Territory Grape Farm||32.6||-2.1||43.5||27 Jan 2011||17.5||-1.6||6.6||16 Oct 2010||430.4||235.3||v high||183%|
|Yulara Aero||33.2||-1.5||46.4||28 Jan 2011||18.5||-0.4||6.9||16 Oct 2010||391.8||208.6||high||188%|
|Offshore Islands (district 200)|
|Northern Endeavour||32.8||36.0||11 Jan 2011||27.5||22.0||27 Dec 2010|
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.
This statement has been prepared based on information available at 2 pm on Wednesday 27 April 2011. Some checks have been made on the data, but it is possible that results will change as new information becomes available.
Averages are long-term means based on observations from
the years 1800 to 2009.
They are not shown for sites with less than 10 years of record in that time, 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
(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.