MEDIA RELEASE  - Friday, 1 May 2009

Northern Territory Wet Season 2008/09

The Top End of the Northern Territory saw a torrid build-up, with hotter than normal temperatures and below average rainfall between October and the middle of December. Australia’s northwest monsoon then set in over northern parts earlier than usual around the middle of December, when Tropical Cyclone Billy developed in the Joseph Boneparte Gulf southwest of Darwin. The monsoon trough remained south of the north coast for most of the time from then untill the middle of February. The Barkly District saw associated widespread flooding rains in early January. More widespread rainfall events, with more of a focus around the southwest of the Top End, occurred during the second half of January. The monsoon trough remained about the base of the Top End for the first half of February, and once again flooding rain was a feature around the eastern Barkly region. The trough retreated to the north coast of the Top End around the middle of February, and made its final retreat offshore late February, resulting in an earlier than usual withdrawal of the monsoon from the Northern Territory. March and April were consequently drier and hotter than usual over most of the Territory. A surge of southeasterly winds progressed to the north coast by the end of April, heralding the end of the wet season and the start of the “The Dry”, which officially begins on May 1.

In southern parts, while the Top End was sweltering in November, a long-running dry spell was broken in dramatic fashion. Alice Springs Airport recorded its wettest November on record, seeing the Todd River flow and a spate of severe thunderstorm events. This was the most significant rainfall period for the season though, without much subsequent follow-up. Central parts of the Territory consequently recorded a hotter than average season.

Darwin

The Darwin wet season total rainfall of 1583.2 mm was close to the long-term average of 1662 mm but almost 300 mm less than the 2007/08 wet season total. Maximum and minimum temperatures were both above average.

Rainfall

Over the Territory as a whole, the area-averaged rainfall was 565.2 mm, which is 58.3 mm above the long-term average. There was a band centred along a line from the southwest corner of the Top End and through the northern Barkly district, coinciding with where the monsoon trough persisted for much of January and early February, that saw above average rainfall for the season. The far northeast corner, and parts of the southern Alice Springs region also saw above average falls. Elsewhere rainfall was near to below average.

The wettest overall was 1894.2 mm at Bradshaw AWS, followed by 1760.4 mm at Dum In Mirrie AWS, followed by 1735.8 mm at Channel Island.

The driest overall was 110.0 mm at Anzac Oval, followed by 110.8 mm at Walungurru AWS, followed by 142.4 mm at Yulara Aero AWS.

Some sites had their highest total Wet Season rainfall on record.

Some sites had their lowest total Wet Season rainfall on record.

The wettest single day was 286.0 mm at Roper River Mataranka on 30 Dec, followed by 262.5 mm at Roper River Mataranka on 29 Dec, followed by 240.0 mm at Claravale on 24 Dec.

Some sites had their highest Wet Season daily rainfall on record.

Maximum temperature

The area-averaged maximum temperature over the Northern Territory was 35.3°C, which is 0.3°C above the long-term average. Cool anomalies were seen in the Victoria River region, as well as northern and eastern parts of the Barkly District, coinciding with the region where the persistent monsoon trough produced above average rainfall. The largest warm anomalies were in northwestern parts of the Alice Springs District.

The hottest day was 45.2°C at Wave Hill on 13 Nov, followed by 45.0°C at Elliott on 22 and 23 Nov, followed by 44.5°C at Elliott on 21 Nov.

The warmest days on average were 38.3°C at Rabbit Flat, followed by 37.1°C at Lajamanu AWS, followed by 36.9°C at Elliott.

The coolest days on average were 31.3°C at McCluer Island AWS, followed by 32.0°C at Gove Airport, followed by 32.3°C at Black Point and Ngayawili AWS.

The coldest day was 19.6°C at Rabbit Flat on 7 Oct, followed by 19.7°C at Arltunga on 8 Nov, followed by 20.5°C at Kulgera on 1 Nov 2008.

Some sites had their highest Wet Season temperature on record.

Some sites had their highest Wet Season mean daily maximum temperature on record.

Minimum temperature

The area-averaged minimum temperature over the Northern Territory was 22.6°C, which is 0.5°C above the long-term average. The pattern of minimum temperatures was similar to the maximums, with below average night-time temperatures over a central band where the monsoon was persistently active, and above average temperatures elsewhere.

The coldest night was 6.1°C at Arltunga on 25 Apr, followed by 6.4°C at Watarrka on 26 Apr, followed by 6.9°C at Arltunga on 13 Oct.

The coolest nights on average were 19.1°C at Alice Springs Airport, followed by 19.7°C at Curtin Springs, followed by 20.0°C at Territory Grape Farm AWS and Yulara Aero AWS.

The warmest nights on average were 26.4°C at Centre Island AWS.

The warmest night was 31.5°C at Yulara Aero AWS on 25 Jan, followed by 30.7°C at Elliott on 23 Nov and Walungurru AWS on 26 Feb, followed by 30.5°C at Port Keats Aero on 26 Nov.

Some sites had their highest Wet Season mean daily minimum temperature on record.

Wind

The strongest wind gust was 102 km/h at Darwin Airport on 15 Oct, followed by 100 km/h at Darwin Airport on 17 Mar, followed by 98 km/h at Yulara Aero AWS on 18 Nov 2008.


Extremes

Hottest day
Highest temperature
45.2°C at Wave Hill on 13 Nov
Warmest days on average
Highest mean daily maximum temperature
38.3°C at Rabbit Flat
Coolest days on average
Lowest mean daily maximum temperature
31.3°C at McCluer Island AWS
Coldest day
Lowest daily maximum temperature
19.6°C at Rabbit Flat on 7 Oct
Coldest night
Lowest temperature
6.1°C at Arltunga on 25 Apr
Coolest nights on average
Lowest mean daily minimum temperature
19.1°C at Alice Springs Airport
Warmest nights on average
Highest mean daily minimum temperature
26.4°C at Centre Island AWS
Warmest night
Highest daily minimum temperature
31.5°C at Yulara Aero AWS on 25 Jan
Wettest overall
Highest total rainfall
1894.2 mm at Bradshaw AWS
Wettest day
Highest daily rainfall
286.0 mm at Roper River Mataranka on 30 Dec
Highest wind gust
102 km/h at Darwin Airport on 15 Oct

Records

Record highest Wet Season daily rainfall
Highest daily rainfall
Wet Season 2008−09 (mm)
Previous highest Years of
record
Bullita 214.0 on 25 Dec 2008 165.1 on 28 Dec 1929 23
Daly Waters AWS 156.8 on 30 Jan 2009 147.1 on 15 Mar 1944 28
Mataranka Station 176.0 on 24 Dec 2008 175.3 on 15 Apr 1963 19



Record highest total Wet Season rainfall
Total rainfall
Wet Season 2008−09 (mm)
Previous highest Years of
record
Kidman Springs 1374.0 1330.2 in 05−06 34



Record lowest total Wet Season rainfall
Total rainfall
Wet Season 2008−09 (mm)
Previous lowest Years of
record
Delamere Weapons Range AWS 494.6 558.2 in 2006 11



Record highest Wet Season temperature
Highest temperature
Wet Season 2008−09 (°C)
Previous highest Years of
record
Pirlangimpi AWS 37.7 on 22 Oct 2008 = 37.7 on 18 Oct 1982 21
Black Point 36.1 on 22 Oct 2008 35.5 on 19 Dec 2006 13



Record highest Wet Season mean daily maximum temperature
Mean daily maximum
temperature
Wet Season 2008−09 (°C)
Previous highest Years of
record
Black Point 32.3 32.2 in 2001−02 13



Record highest Wet Season mean daily minimum temperature
Mean daily minimum
temperature
Wet Season 2008−09 (°C)
Previous highest Years of
record
Black Point 25.9 = 25.9 in 2005−06 13




Summaries

This table is very wide and may not fit if printed.

Summary statistics for Wet Season 2008−09
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean Diff
from
average
Highest Mean Diff
from
average
Lowest Total Rank Fraction of
average
Darwin-Daly (district 14GA)
Batchelor Aero AWS 34.3   39.5 14 Oct 2008 23.5   14.7 30 Apr 2009 1236.4
Black Point 32.3 +0.4 36.1 22 Oct 2008 25.9 +0.5 22.3 30 Mar 2009 983.2 low 81%
Bradshaw AWS 36.5   41.5 23 Nov 2008 24.6   14.6 30 Apr 2009 1894.2
Darwin Airport 33.0 +0.6 37.5 22 Oct 2008 25.2 +0.4 20.6 16 Oct 2008 1583.2 average 96%
Douglas River 35.4 +0.4 41.4 22 Oct 2008 23.2 +0.2 14.0 29 Apr 2009
Dum In Mirrie AWS 32.4   37.7 23 Oct 2008 25.7   19.2 30 Apr 2009 1760.4
Jabiru Airport AWS 35.4 +0.5 40.1 13 Oct 2008 24.8 +0.4 21.7 30 Apr 2009 1185.2 low 79%
Katherine Aviation Museum 35.4 0.0 40.3 21 Nov 2008 23.1 −0.6 12.9 30 Apr 2009 1214.8 average 111%
Mango Farm 35.0 +0.2 40.5 13 Oct 2008 23.2 0.0 17.5 30 Apr 2009 1597.7 high 119%
McCluer Island AWS 31.3   34.9 9 Dec 2008 26.7   22.7 30 Mar 2009 951.6 average 83%
Pine Creek Council 34.7   39.3 12 Oct 2008 23.8   18.6 29 Apr 2009 1557.4
Tindal RAAF AWS 35.5 +0.4 40.7 31 Oct 2008 23.5 −0.2 13.9 30 Apr 2009 1085.0 average 101%
Arnhem (district 14BC)
Alyangula Police 32.5 −0.4 36.8 21 Nov 2008 25.0 +0.2 20.7 22 Oct 2008 1398.0 high 123%
Gove Airport 32.0 +0.1 36.4 28 Nov 2008 24.1 +0.4 19.7 27 Oct 2008 1289.2 average 100%
Groote Eylandt Airport AWS 33.6   39.3 21 Nov 2008 23.6   17.7 28 Apr 2009 1656.2
Maningrida Aero AWS 32.8   36.4 10 Nov 2008 24.7   20.1 28 Apr 2009 876.0
Ngayawili AWS 32.3   36.6 10 Nov 2008 24.8   21.3 29 Oct 2008 1521.0
Roper-Mcarthur (district 14DE)
Borroloola AWS 35.4 +0.3 42.6 22 Nov 2008 23.1 −0.4 13.0 29 Apr 2009 419.8 low 45%
Centre Island AWS 33.7 +0.3 38.3 16 Dec 2008 26.4 +0.2 22.6 8 Jan 2009 715.4 low 71%
Daly Waters AWS 36.1 +0.1 42.5 21 Nov 2008 21.9 −0.9 14.3 18 Mar 2009 1154.8 very high 186%
Larrimah 35.5 −0.3 40.6 25 Nov 2008 22.4 −0.7 10.5 29 Apr 2009 1202.4 high 145%
McArthur River Mine 36.6 0.0 42.2 22 Nov 2008 24.0 +0.6 14.2 29 Apr 2009 946.4 high 128%
Ngukurr 36.0 −0.2 42.1 25 Nov 2008     18.0 29 Apr 2009 671.2 average 92%
Wollogorang 35.2 −0.4 41.5 7 Nov 2008 22.5 −0.1 13.0 28 Apr 2009 1161.7 high 126%
Victoria (district 14F)
Kidman Springs 36.6 −0.1 41.6 4 Nov 2008 23.6 −0.4 11.5 30 Apr 2009 1374.0 highest 191%
Lajamanu AWS 37.1 +0.7 42.8 1 Nov 2008 22.3 0.0 11.0 29 Apr 2009 382.8 average 80%
Timber Creek 36.6 +0.1 42.0 25 Nov 2008 23.4 −0.8 12.9 29 Apr 2009 1279.3 very high 138%
Victoria River Downs 36.6 +0.2 43.1 21 Nov 2008 23.2 −0.3 11.1 30 Apr 2009 929.7 very high 148%
Wave Hill 36.4 −0.4 45.2 13 Nov 2008 22.5 −0.2 10.1 30 Apr 2009 848.8 high 128%
Barkly (district 15A)
Elliott 36.9 −0.3 45.0 23 Nov 2008 22.6 −0.1 14.5 29 Apr 2009 756.1 high 131%
Tennant Creek Airport 35.4 +0.2 42.0 22 Nov 2008 23.5 +0.1 15.5 29 Apr 2009 497.0 average 115%
Alice Springs (district 15B)
Alice Springs Airport 33.8 +0.7 41.3 6 Feb 2009 19.1 +1.2 7.6 29 Apr 2009 236.8 high 110%
Curtin Springs 35.0 +0.8 44.0 6 Feb 2009 19.7 +1.4 7.0 25 Apr 2009 156.1 average 93%
Jervois 35.6 +0.3 43.4 4 Dec 2008 20.8 +1.7 8.8 28 Apr 2009 205.8 average 88%
Papunya 35.9   42.1 13 Nov 2008 20.5   11.0 29 Apr 2009 174.4 average 85%
Rabbit Flat 38.3 +1.2 43.7 12 Jan 2009 21.7 +0.1 9.8 25 Oct 2008 232.8 low 47%
Territory Grape Farm AWS 35.2 +0.6 41.3 14 Nov 2008 20.0 +1.0 9.6 30 Apr 2009 154.4 low 58%
Watarrka 34.9 −0.1 42.5 6 Feb 2009     6.4 26 Apr 2009 273.3 high 117%
Yulara Aero AWS 35.0 +0.3 44.2 6 Feb 2009 20.0 +1.2 7.2 24 Apr 2009 142.4 average 66%

Further information

NT Climate Services Centre
Bureau of Meteorology
Phone (08) 8920 3813
Email climate.nt@bom.gov.au