Wet season 2009 - 2010

Rainfall was average to very much above average during the Northern Territory's wet season (October 2009 - April 2010). It started with dry conditions during October and November but had good falls during December and January.   Widespread heavy rainfall occurred from the 10th of December for several days mainly due to the weather associated with Tropical Cyclone Laurence.  It wasn't until 5 January when north-westerly winds descended on Darwin, and the associated rainfall marked the onset of the monsoon.

Tropical Cyclone Laurence in December, Ex-Tropical Cyclone Olga in January and Tropical Cyclone Paul in March all formed close to the Northern Territory coast and produced significant rainfall in various parts of the Territory.  Ex-TC Laurence produced heavy rainfall through the Alice Springs District in January and was followed by another tropical low at the end of February - producing two very substantial rainfall events for the season. The Todd river in Alice Springs flowed on at least four occasions during the season.

Rainfall over the north-western parts of the Territory during March was below normal, but was above normal in April. A surge of south-easterly winds progressed to the north coast by the end of April, heralding the end of the wet season and the start of “The Dry”, which officially began on 1 May.

In southern parts, the dry conditions remained for the first three months of the season. From January onwards Alice Springs Airport recorded above average rainfall in each month. For the second time during the recording period, January and February both recorded more than 100 mm of rainfall each (the previous occurrence was in 1974).  

Darwin

Darwin's wet season total rainfall of 2015.6 mm was well above the long-term average of 1662 mm. This is the highest wet season rainfall total since the 1999 - 2000 season. Maximum and minimum temperatures were both above average during the season.

Alice Springs

Total rainfall recorded at Alice Springs for the period October 2009 to April 2010 was 404.4mm, well above the long-term mean of 216.0mm. The maximum and  minimum temperatures remained within 1°C of the long term average.

Rainfall

Over the Territory as a whole, the area-averaged rainfall was 565.2mm, which is 58.3mm above the long-term average. There was a band centred along a line from the southwest corner of the Top End 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 average.

The wettest site overall was Channel Island which recorded a total of 2313.4 mm at for the wet season. This was followed by 2237.2 mm at Nightcliff Pool and then 2165.2 mm at Pinelands.

Some sites had their highest total wet season rainfall on record.

The wettest day of the season occured at Bulman AWS on 31 Mar 2010 when they observed 442.8 mm while Ex-TC Paul was in the area. This was followed by 358.4 mm at Centre Island AWS on 1 Apr 2010 and then by 290.2 mm at Channel Island on 13 Dec 2009.

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 south-western parts of the Alice Springs District.

The hottest day was 46.0 °C at Rabbit Flat on 8 Dec 2009, followed by 45.8 °C at Jervois on 9 Dec 2009, and then 45.6 °C at Rabbit Flat on 9 Dec 2009.

The warmest days on average were 37.6 °C at Kidman Springs, followed by 37.4 °C at Timber Creek and Victoria River Downs, followed by 37.3 °C at Bradshaw AWS.

The coolest days on average were 31.8 °C at Gove Airport, followed by 32.4 °C at Cape Don AWS and Point Fawcett AWS, followed by 32.5 °C at Dum In Mirrie AWS

The coldest day was 16.0 °C at Arltunga on 11 Dec 2009, followed by 18.9 °C at Watarrka on 13 Mar 2010 and then followed by 19.1 °C at Territory Grape Farm on 11 Dec 2009.

Some sites had their highest wet seasonal 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. Minimum temperatures were largely close to average, with above average temperatures in the far south.

The coldest night was 5.6 °C at Arltunga on 30 Apr 2010, followed by 5.7 °C at Watarrka on 2 Oct 2009 and then 5.8 °C at Arltunga on 29 Apr 2010.

The coolest nights on average were 18.2 °C at Alice Springs Airport, followed by 19.1 °C at Kulgera and then 19.2 °C at Curtin Springs.

The warmest nights on average were 26.4 °C at Cape Don AWS, followed by 26.0 °C at Warruwi and then 25.8 °C at Dum In Mirrie AWS.

The warmest night was 32.2 °C at Rabbit Flat on 9 Dec 2009 and Jervois on 24 Dec 2009, followed by 31.8 °C at Lajamanu on 22 Nov 2009.

Wind

The strongest wind gust was 126 km/h at Darwin Airport on 27 Feb 2010, followed by 120 km/h at Borroloola AWS on 13 Nov 2009 and then 119 km/h at Yulara Aero AWS on 23 Dec 2009.

Further information

Media
(03) 9669 4057
Enquiries

Extremes in wet season 2009 - 2010
Hottest day 46.0 °C at Rabbit Flat on 8 Dec 2009
Warmest days on average 37.6 °C at Kidman Springs
Coolest days on average 31.8 °C at Gove Airport
Coldest day 16.0 °C at Arltunga on 11 Dec 2009
Coldest night 5.6 °C at Arltunga on 30 April 2010
Coolest nights on average 18.2 °C at Alice Springs Airport
Warmest nights on average 26.4 °C at Cape Don AWS
Warmest night 32.2 °C at Rabbit Flat on 9 Dec 2009 and Jervois on 24 Dec 2009
Wettest overall 2313.4 mm at Channel Island
Wettest day 442.8 mm at Bulman AWS on 31 Mar 2010
Highest wind gust 126 km/h at Darwin Airport on 27 Feb 2010

Record highest wet season daily rainfall
Highest daily rainfall (mm) Previous highest (mm) Years of
record
Tarlton Downs 123.0 on 28 Feb 2010 120.0 on 7 Jan 2007 43
Mallapunyah 282.0 on 29 Jan 2010 254.0 on 22 Mar 1964 39
Darwin River Dam 285.0 on 13 Dec 2009 208.4 on 10 Dec 1998 35
Channel Island 290.2 on 13 Dec 2009 249.6 on 3 Jan 1997 25
Atula 119.2 on 28 Feb 2010 118.1 on 3 Feb 1979 28
Stokes Hill 273.6 on 13 Dec 2009 246.6 on 16 Mar 1977 11
Wallace Rock Hole 109.6 on 9 Jan 2010 88.6 on 12 Feb 2000 21
Territory Grape Farm 111.0 on 7 Jan 2010 110.0 on 7 Feb 1991 12
The Granites 196.0 on 7 Jan 2010 173.9 on 24 Jan 1987 14
Nelson Springs 167.0 on 6 Jan 2010 143.4 on 12 Mar 2006 14
Trephina Gorge 195.4 on 9 Jan 2010 130.0 on 31 Mar 1988 15
Waite River 191.0 on 7 Jan 2010 143.0 on 7 Feb 1998 17
Batchelor Aero AWS 223.6 on 13 Dec 2009 197.8 on 3 Mar 2007 16
Bing Bong Port 266.0 on 1 Apr 2010 220.0 on 18 Mar 2006 12



Record highest total wet season rainfall
Total rainfall (mm) Previous highest (mm) Years of
record
Average (mm)
Atula 540.4 404.2 in 2000 - 2001 28 200.8
Nightcliff Pool 2237.2 1877.4 in 1966 - 1967 13 1392.9
Territory Grape Farm 441.6 398.4 in 1990 - 1991 10 223.8



Record highest wet season temperature
Highest temperature (°C) Previous highest (°C) Years of
record
Average (°C)
Black Point 36.1 on 19 Oct 2009 = 36.1 on 22 Oct 2008 14 32.0
Lajamanu 45.4 on 8 Dec 2009 45.0 on 5 Dec 2004 13 36.5
Dum In Mirrie AWS 38.0 on 18 Oct 2009 37.7 on 23 Oct 2008 10 32.1



Record highest wet season mean daily maximum temperature
Mean daily maximum
temperature (°C)
Previous highest (°C) Years of
record
Average (°C)
Dum In Mirrie AWS 32.5 32.4 in 2008 - 2009 10 32.1




Record highest wet season daily minimum temperature
Highest temperature (°C) Previous highest (°C) Years of
record
Average (°C)
Darwin Airport 29.7 on 10 Dec 2009 = 29.7 on 3 Dec 2007 65 24.8
Black Point 30.2 on 9 Dec 2009 30.0 on 26 Nov 1998 14 25.5
Lajamanu 31.8 on 22 Nov 2009 30.1 on 2 Dec 2007 12 22.2
Rabbit Flat 32.2 on 9 Dec 2009 31.2 on 30 Nov 1996 10 21.5



Record highest wet season mean daily minimum temperature
Mean daily minimum
temperature (°C)
Previous highest (°C) Years of
record
Average (°C)
Tindal RAAF 24.5 24.3 in 1997 - 1998 18 23.7
Delamere Weapons Range 24.2 24.1 in 2002 - 2003 11 23.6
Batchelor Aero AWS 23.8 23.7 in 2005 - 2006 10 23.3

Summary statistics for wet season 2009-2010
Maximum temperatures (°C) Minimum temperatures (°C) Rainfall (mm)
Mean Diff
from
average
Highest Mean Diff
from
average
Lowest Total Average Rank Fraction of
average
Darwin-Daly (district 14GA)
Batchelor Aero AWS 34.3 +0.1 39.2 3 Oct 2009 23.8 +0.5 17.8 19 Oct 2009 1661.4 1497.6 average 111%
Bradshaw AWS 37.3   44.0 5 Dec 2009 25.1   17.3 19 Oct 2009 1113.8
Cape Don AWS 32.4   35.8 6 Dec 2009 26.4   22.8 11 Dec 2009 1199.2 1230.7 average 97%
Central Arnhem Plateau AWS 33.3   39.4 15 Nov 2009 22.9   12.9 7 Oct 2009 1420.0
Darwin Airport 33.0 +0.6 38.0 18 Oct 2009 25.1 +0.3 22.3 19 Oct 2009 2015.6 1661.1 high 122%
Delamere Weapons Range AWS 36.3 +0.9 42.2 5 Dec 2009 24.2 +0.6 17.6 8 Oct 2009 478.0 893.8 lowest 53%
Dum In Mirrie AWS 32.5 +0.4 38.0 18 Oct 2009 25.8 +0.4 21.0 19 Oct 2009 1825.4 1749.4 average 104%
Jabiru Airport AWS 35.7 +0.8 41.2 18 Nov 2009 24.7 +0.4 18.1 8 Oct 2009 1568.0 1503.2 average 104%
Katherine Aviation Museum 35.6 +0.1 41.5 9 Dec 2009 23.9 +0.3 14.3 8 Oct 2009 1033.4 1105.0 average 94%
Mango Farm 35.6 +0.8 41.0 3 Oct 2009 23.1 -0.1 13.2 8 Oct 2009 1360.1 1376.5 average 99%
Middle Point AWS 35.2   40.2 17 Oct 2009 23.6   16.2 19 Oct 2009 1116.0
Noonamah AWS 35.0   40.8 17 Oct 2009 23.9   16.7 19 Oct 2009 1987.4
Pine Creek Council 34.9   39.7 18 Nov 2009 24.1   20.4 8 Oct 2009 1212.7
Pirlangimpi AWS 33.2 +0.8 36.8 18 Oct 2009 24.6 +0.7 20.4 19 Oct 2009 2069.4 1929.3 average 107%
Point Fawcett AWS 32.4 +0.3 36.3 17 Oct 2009 25.1 +0.1 18.8 19 Oct 2009 1453.2 1429.9 average 102%
Tindal RAAF AWS 35.6 +0.5 41.1 15 Nov 2009 24.5 +0.8 15.2 19 Oct 2009 782.4 1075.5 low 73%
Arnhem (district 14BC)
Gove Airport 31.8 -0.1 36.1 2 Dec 2009 23.9 +0.2 18.9 26 Oct 2009 1271.8 1286.7 average 99%
Groote Eylandt Airport AWS 33.4 0.0 37.8 3 Dec 2009 23.3 -0.3 13.9 7 Oct 2009 1549.8 1334.6 high 116%
Maningrida Aero AWS 32.9   37.3 18 Oct 2009 24.5   17.1 7 Oct 2009 1331.2
Warruwi AWS 32.7 +0.5 36.4 3 Dec 2009 26.0 +0.4 23.3 11 Dec 2009 972.8 1127.5 average 86%
Roper-Mcarthur (district 14DE)
Borroloola AWS 35.0 -0.1 40.7 2 Dec 2009 23.2 -0.2 13.3 6 Oct 2009 1198.0 888.1 high 135%
Bulman AWS 35.8   41.2 15 Nov 2009 23.4   12.4 7 Oct 2009 1498.0
Larrimah 35.7 0.0 41.5 8 Dec 2009 22.8 -0.3 13.0 10 Oct 2009 678.2 840.7 average 81%
McArthur River Mine 36.2 -0.4 41.9 6 Dec 2009 24.0 +0.6 14.5 10 Oct 2009 929.6 721.2 high 129%
Wollogorang 34.9 -0.7 41.5 7 Dec 2009 22.4 -0.2 10.7 6 Oct 2009 1718.7 908.8 v high 189%
Victoria (district 14F)
Kidman Springs 37.6 +0.8 43.5 7 Dec 2009 24.5 +0.6 12.2 19 Oct 2009 496.2 740.5 low 67%
Lajamanu 36.8 +0.3 45.4 8 Dec 2009 22.5 +0.3 11.6 10 Oct 2009 618.6 471.3 high 131%
Timber Creek 37.4 +0.9 43.5 7 Dec 2009 24.4 +0.3 12.0 11 Oct 2009 684.3 953.6 low 72%
Victoria River Downs 37.4 +1.0 43.4 8 Dec 2009 24.0 +0.5 12.2 10 Oct 2009 607.4 636.0 average 96%
Wave Hill 37.2 +0.4 44.6 7 Dec 2009 23.2 +0.5 11.3 10 Oct 2009 647.8 661.1 average 98%
Barkly (district 15A)
Elliott 36.9 -0.3 43.5 9 Dec 2009 22.6 0.0 11.5 10 Oct 2009 738.4 573.9 high 129%
Tennant Creek Airport 34.8 -0.5 43.0 8 Dec 2009 23.3 -0.1 16.1 24 Nov 2009 585.6 427.6 high 137%
Alice Springs (district 15B)
Alice Springs Airport 32.8 -0.4 43.2 8 Dec 2009 18.2 +0.3 6.3 18 Oct 2009 404.4 213.2 v high 190%
Curtin Springs 34.4 +0.2 44.0 7 Dec 2009 19.2 +0.9 8.0 3 Oct 2009 156.3 166.9 average 94%
Jervois 34.1 -1.2 45.8 9 Dec 2009 20.2 +1.1 7.9 9 Oct 2009 568.2 227.8 v high 249%
Kulgera 32.8 -0.2 43.0 27 Jan 2010 19.1 +0.7 6.9 18 Oct 2009 119.2 196.2 low 61%
Rabbit Flat 37.1 -0.2 46.0 8 Dec 2009 21.4 -0.1 7.6 19 Oct 2009 330.6 451.6 average 73%
Watarrka 34.0 -1.0 43.4 17 Nov 2009 20.3 -0.2 5.7 2 Oct 2009 433.8 233.6 high 186%
Yulara Aero AWS 34.4 -0.3 43.8 7 Dec 2009 19.5 +0.7 6.6 3 Oct 2009 241.6 206.8 high 117%

Notes

This statement has been prepared based on information available at 9 am on Tuesday 4 May 2010. 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 2010. 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.

Further information

Media
(03) 9669 4057
Enquiries