Thursday, 1 October 2009 - Monthly Climate Summary for Northern Territory - Product code IDCKGC22R0

Northern Territory in September 2009
Warm and Windy

September was warmer than usual overall, with both maximum and minimum temperatures above the long-term average. Rainfall values were close to normal across the Territory, but wetter than usual in the northwest due to a wet start to the month. Severe thunderstorms and dust storms were observed in the Alice Springs District.

Darwin
Darwin had a wet start to September, with afternoon showers about from the 5th to the 12th. Overall, Darwin Airport recorded a total rainfall of 34.4 mm for the month, which is 20.6 mm above its long-term September mean. Darwin also experienced a warm September this year, with the mean maximum temperature of 33.4°C being 0.9°C greater than the long-term September mean, and the mean minimum temperature of 24.0°C being 1.0°C above the long-term September mean.

Alice Springs
Alice Springs Airport recorded a total rainfall of 6.0 mm for September, which is 2.1 mm below its long-term mean. These rain events were due to shower and thunderstorm activity ahead of troughs over WA. It was quite windy ahead of one of these troughs on the 15th and 16th, with a maximum wind gust of 81km/h recorded on the 16th. Alice Springs was much warmer than normal this September, with a mean maximum temperature of 29.7°C being 2.5°C greater than climatology, and a mean minimum temperature of 14.2°C being 3.9°C above climatology!

An archive of previous monthly summaries for Northern Territory is also available, as are summaries for other states and many other climate summaries and diagnostics.

 

Rainfall

The northwest Darwin-Daly District experienced a wet start to the month, with afternoon showers about from the 5th to the 12th, and a few isolated storms. The highest rainfall amount recorded within this period was 62 mm at Elizabeth Valley on the 8th.

Thundery showers were about in the southwest Alice Springs District on the 14th, 15th and 16th ahead of a trough over Western Australia. No rainfall was recorded in any rain gauges on the 14th or 15th, but Watarrka recorded 0.8 mm of rain on the 16th. More showers and thunderstorms were about on the 17th, 18th and 19th ahead of another trough over WA, with widespread falls recorded at several stations.

Some areas of the northern Darwin-Daly, western Arnhem and southern Alice Springs districts had slightly more rainfall than usual for the month of September. The rest of the Territory was just under the long-term September average.

The average rainfall over the whole of the Territory was 3.7 mm which is 3.2 mm less than the long-term average of 6.9 mm.

The wettest overall was 86.6 mm at Noonamah AWS, followed by 84.8 mm at Elizabeth Valley, and then by 66.4 mm at Darwin River Ridge.

Some sites had their highest total September rainfall on record.

The wettest single days were all on the 8th with 62.2 mm at Elizabeth Valley, followed by 61.2 mm at Noonamah AWS, and then by 39.8 mm at Humpty Doo Fire Station.

Some sites had their highest September daily rainfall on record.

Maximum temperature

All stations across the Territory recorded mean maximum temperatures warmer than their long-term mean for September, with several stations recording their warmest September on record. Stations across the Territory recorded maximum temperatures of between 1 to 3°C greater than climatology, with areas in the southwest recording maximum temperatures of around 3 to 4°C above climatology.

The area-averaged maximum temperature was 33.6°C, which was 2.2°C warmer than the long-term average of 31.4°C.

The hottest days were all on the 23rd, with 41.5°C at Bradshaw AWS, followed by 41.1°C at Port Keats Aero, and then by 40.6°C at Mango Farm.

The warmest days on average were 38.3°C at Bradshaw AWS, followed by 38.2°C at Douglas River, and then by 38.1°C at Timber Creek.

The coolest days on average were 27.5°C at Kulgera, followed by 29.6°C at Arltunga, and then by 29.7°C at Alice Springs Airport.

The coldest day was 18.8°C at Kulgera on the 26th, followed by 20.2°C at Alice Springs Airport on the 26th, and then by 20.4°C at Kulgera on the 27th.

Some sites had their highest September temperature on record.

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

 

Minimum temperature

Average minimum temperatures have been much warmer than usual across the Territory this month, apart from a small area in the eastern Roper-McArthur District. Almost all stations recorded mean minimum temperatures of 1 to 3°C above climatology, with some sites in the south recording mean minimums of up to 5°C warmer than the long-term average. Some sites had their warmest September minimums on record.
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The area-averaged minimum temperature was 18.0°C, which was 2.1°C above the long-term average of 15.9°C.

The coldest night was 3.0°C at Curtin Springs on the 11th, followed by 3.1°C at Yulara Aero AWS on the 8th, and then by 3.2°C at Arltunga on the 9th and on the 28th.

The coolest nights on average were 11.8°C at Yulara Aero AWS, followed by 12.3°C at Curtin Springs, and then by 12.3°C at Kulgera.

The warmest nights on average were 25.0°C at Warruwi AWS.

The warmest night was 28.5°C at Kidman Springs on the 22nd, followed by 28.0°C at Kidman Springs on the 6th and 26th, and then by 27.9°C at Dum In Mirrie AWS on the 23rd.

Some sites had their warmest September night (highest daily minimum temperature) on record.

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

 

Wind

The strongest wind gust was 117 km/h at Yulara Aero AWS on the 16th, followed by 81 km/h at Alice Springs Airport on the 16th, and then by 80 km/h at Yulara Aero AWS on the 2nd.

 

Other phenomena

Severe Thunderstorms

Severe thunderstorms were observed on radar in the Alice Springs District from the 16th to the 19th ahead of a trough over WA. On the 16th, these storms were observed near Yulara and Curtin Springs, with a 117km/h wind gust recorded at Yulara AWS and a dust storm reported. Wind gusts were estimated to 111km/h at Curtin Springs, with large trees uprooted, and a very thick dust storm reported. Several other severe thunderstorms were observed on radar, in the northeast Alice Springs District on the 17th, and in the southern Alice Springs District on the 18th and 19th. A 117km/h was recorded at Oodnadatta (in South Australia) on the 19th.

Dust Storms

On the 21st a dust storm was reported at Kulgera ahead of a strong cold front moving in from the west. This cold front brought fresh to strong and gusty westerlies over the Alice Springs District on the 22nd with more areas of raised dust. This front continued east through NSW and Queensland, with dust reducing visibility across NSW and southern QLD on the 23rd. This dust eventually reached the north Island of New Zealand on the 24th, after the front carried this dust across the Tasman Sea.

 

Further information

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

Extremes

Hottest day
Highest temperature
41.5°C at Bradshaw AWS on the 23rd *
Warmest days on average
Highest mean daily maximum temperature
38.3°C at Bradshaw AWS *
Coolest days on average
Lowest mean daily maximum temperature
27.5°C at Kulgera
Coldest day
Lowest daily maximum temperature
18.8°C at Kulgera on the 26th
Coldest night
Lowest temperature
3.0°C at Curtin Springs on the 11th
Coolest nights on average
Lowest mean daily minimum temperature
11.8°C at Yulara Aero AWS
Warmest nights on average
Highest mean daily minimum temperature

25.0°C at Warruwi AWS
Warmest night
Highest daily minimum temperature
28.5°C at Kidman Springs on the 22nd
Wettest overall
Highest total rainfall
86.6 mm at Noonamah AWS
Wettest day
Highest daily rainfall
62.2 mm at Elizabeth Valley on the 8th
Highest wind gust
117 km/h at Yulara Aero AWS on the 16th
* Bradshaw AWS recorded the highest September temperature for the Northern Territory and its hottest September temperature to date, but is not included in the Records Table due to its short climate record of 8 years.

Records

Record highest September daily rainfall
Highest daily rainfall
(mm)
Previous highest
Years of
record
Palm Valley 19.0 on the 17th 18.2 on the 1st in 1997 26
Elizabeth Valley 62.2 on the 8th 53.0 on the 29th in 1986 23
Karama 35.0 on the 8th 17.7 on the 29th in 2007 21



Record highest total September rainfall
Total rainfall
(mm)
Previous highest
Years of
record
Elizabeth Valley 84.8 53.0 in 1986 23
Batchelor Aero AWS 26.6 14.0 in 1999 12



Record highest September temperature
Highest temperature
(°C)
Previous highest
Years of
record
Mango Farm 40.6 on the 23rd 40.5 on the 27th in 1997 28
Black Point 34.7 on the 25th 34.4 on the 25th in 2008 17
Lajamanu AWS 40.3 on the 21st 40.0 on the 30th in 2005 14
Groote Eylandt Airport AWS 36.4 on the 25th 36.0 on the 23rd in 2007 10



Record highest September mean daily maximum temperature
Mean daily maximum
temperature (°C)
Previous highest Years of
record
Jabiru Airport AWS 37.5 37.4 in 2008 31
Mango Farm 37.8 37.5 in 1997 28
Timber Creek 38.1 37.7 in 2005 28
Pirlangimpi AWS 34.6 33.9 in 2008 24
Douglas River 38.2 37.6 in 1997 18
Borroloola AWS 35.9 35.8 in 1997 13
Channel Point 31.8 31.3 in 2004 11
Delamere Weapons Range AWS 36.7 36.4 in 2005 12
Point Fawcett 32.7 32.6 in 1998 11
Dum In Mirrie AWS 32.1 32.0 in 2004 10
Groote Eylandt Airport AWS 33.3 33.2 in 2001 10



Record highest September daily minimum temperature
Highest daily minimum
temperature (°C)
Previous highest Years of
record
Darwin Airport 27.2 on the 22nd 26.7 on the 27th in 1998 68
Alice Springs Airport 27.4 on the 21st 26.0 on the 24th in 1971 67
Curtin Springs 22.4 on the 21st = 22.4 on the 28th in 2006 44
Mango Farm 25.6 on the 24th 24.5 on the 16th in 1998 28
Territory Grape Farm AWS 26.2 on the 21st 24.0 on the 23rd in 2003 16
Lajamanu AWS 27.5 on the 21st 27.2 on the 24th in 1971 14
Channel Point 27.0 on the 22nd 26.7 on the 30th in 1996 12
Batchelor Aero AWS 24.9 on the 24th 24.2 on the 29th in 1997 12
Kidman Springs 28.5 on the 22nd 28.2 on the 20th in 2008 13
Point Fawcett 27.7 on the 23rd 26.9 on the 23rd in 2003 11
Dum In Mirrie AWS 27.9 on the 23rd 27.0 on the 25th in 2003 10



Record highest September mean daily minimum temperature
Mean daily minimum
temperature (°C)
Previous highest Years of
record
Alice Springs Airport 14.2 13.7 in 1996 67
Jervois 14.4 = 14.4 in 1997 41
Channel Point 23.5 22.9 in 2005 14
Batchelor Aero AWS 22.5 21.9 in 1992 13
Dum In Mirrie AWS 24.7 24.2 in 2005 10
McCluer Island AWS 25.4 25.2 in 2000 10




Summaries

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

Summary statistics for September 2009
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(mm)
Mean Diff
from
average
Highest Mean Diff
from
average
Lowest Total Rank Fraction
Darwin-Daly (district 14GA)
Batchelor Aero AWS 36.6 +0.6 38.0 23rd 22.5 +2.1 16.6 29th 26.6 highest 719%
Black Point 32.4 +0.9 34.7 25th 24.1 +1.2 21.4 29th 2.1 very high 233%
Bradshaw AWS 38.3 +1.3 41.5 23rd 23.4 +1.6 18.2 8th 0
Cape Don AWS 31.6   33.4 28th 24.9   23.5 3rd 0 lowest 0%
Central Arnhem Plateau AWS 34.5   36.2 7th 20.4   13.4 29th 23.8
Channel Point 31.8 +0.9 35.0 28th 23.5 +2.1 17.9 29th 0.6 average 11%
Darwin Airport 33.4 +0.9 35.2 24th 24.0 +1.0 22.0 8th 34.4 high 236%
Delamere Weapons Range AWS 36.7 +1.2 39.8 23rd 21.5 +0.8 15.6 30th 0.4 average 10%
Douglas River 38.2 +1.7 40.4 23rd 21.1 +2.6 14.5 29th 0 lowest 0%
Dum In Mirrie AWS 32.1 +0.7 33.5 16th 24.7 +1.8 21.4 29th 31.6 very high 343%
Jabiru Airport AWS 37.5 +1.4 38.7 26th 23.0 +1.5 20.1 29th 24.2 high 384%
Katherine Aviation Museum 36.7 +0.9 39.0 23rd 21.5 +1.5 14.0 29th 0.2 average 3%
Mango Farm 37.8 +1.6 40.6 23rd 20.3 +1.0 16.7 29th 0.5 average 6%
McCluer Island AWS 29.7 +0.6 31.3 23rd 25.4 +0.8 23.8 1st 1.6 very high 800%
Middle Point AWS 37.2   38.4 15th 21.0   18.0 19th 35.8
Noonamah AWS 37.2   39.1 1st 22.1   19.0 19th 86.6
Pine Creek Council 36.4   38.4 23rd 22.9   18.4 29th 6.8
Pirlangimpi AWS 34.6 +1.7 36.3 25th 22.9 +1.7 21.0 2nd 24.8 average 87%
Point Fawcett AWS 32.7 +0.8 34.4 27th 22.0 +0.6 18.2 19th 0.4 average 7%
Tindal RAAF AWS 37.0 +1.4 39.5 23rd 22.2 +2.2 17.3 29th 1.2 average 16%
Arnhem (district 14BC)
Alyangula Police 31.4 +0.2 33.0 24th 21.5 +1.3 18.4 29th 0.3 average 8%
Gove Airport 30.9 +0.7 32.5 24th 20.4 +0.8 17.8 18th 0 lowest 0%
Groote Eylandt Airport AWS 33.3 +0.7 36.4 25th 18.4 +0.9 14.4 12th 0.2 low 11%
Maningrida Aero AWS 32.5   36.2 27th 21.6   17.4 29th 0
Milingimbi AWS 32.4   35.7 28th 22.2   19.0 29th 0
Ngayawili AWS 32.6   34.4 28th 21.4   19.7 1st 0.2
Warruwi AWS 31.5 +0.7 33.8 29th 25.0 +1.5 23.4 1st 0.2 high 22%
Roper-Mcarthur (district 14DE)
Borroloola AWS 35.9 +1.0 39.2 26th 18.2 +0.6 13.4 29th 0 lowest 0%
Daly Waters AWS 36.5 +2.0 39.3 22nd 17.8 +0.7 7.9 29th 0 lowest 0%
Larrimah 36.4 +1.3 38.5 22nd 19.4 +1.0 10.5 29th 0 lowest 0%
McArthur River Mine 36.8 +1.6 39.3 26th 19.3 +2.3 13.7 30th 0.2 average 4%
Wollogorang 35.2 +0.9 37.9 25th 16.0 +0.2 9.3 29th 0 lowest 0%
Victoria (district 14F)
Kidman Springs 37.7 +1.0 40.0 23rd     13.9 30th 0 lowest 0%
Timber Creek 38.1 +1.7 39.8 22nd 20.9 +0.3 14.8 8th 0 lowest 0%
Victoria River Downs 37.7 +2.2 39.8 22nd 19.0 +0.8 11.7 29th 0 lowest 0%
Wave Hill 36.7 +1.6 39.0 22nd 20.1 +2.2 11.4 29th 0 lowest 0%
Barkly (district 15A)
Elliott 36.4 +1.1 40.0 22nd 18.0 +0.6 9.5 29th 0 lowest 0%
Tennant Creek Airport 33.5 +1.9 38.6 22nd 19.5 +1.1 13.6 27th 5.8 average 72%
Alice Springs (district 15B)
Alice Springs Airport 29.7 +2.5 37.4 21st 14.2 +3.9 4.0 28th 6.0 average 74%
Arltunga 29.6   36.2 20th 12.5   3.2 9th 2.4 average 44%
Curtin Springs 29.7 +2.0 36.8 20th 12.3 +2.4 3.0 11th 14.2 high 161%
Jervois 31.4 +1.6 39.2 21st 14.4 +3.2 4.8 9th 0.6 average 10%
Kulgera 27.5 +0.5 36.2 16th 12.3 +1.1 3.5 27th 15.8 high 103%
Rabbit Flat 36.2 +1.7 40.1 20th 16.7 +2.2 7.2 25th 0 lowest 0%
Territory Grape Farm AWS 31.3 +0.8 37.1 20th 13.1 +0.9 4.7 28th 2.2 average 27%
Watarrka 30.3 +0.6 35.4 21st 13.6 +0.3 3.4 9th 10.2 high 140%
Yuendumu 32.1 +2.6 37.2 20th 15.6 +2.6 8.6 10th 2.9 average 34%
Yulara Aero AWS 29.9 +1.1 35.9 19th 11.8 +1.1 3.1 8th 6.8 high 121%

Notes

This statement has been prepared based on information available at 10 am on Thursday 1 October 2009. 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 2008. 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 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.

Further information

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