Tuesday, 3 January 2012 - Monthly Climate Summary for Northern Territory - Product code IDCKGC22R0

Northern Territory in December 2011: A mix of wet & dry, hot & cool

Tropical Cyclone Grant brought heavy rains to the eastern Top End. Gove and Jabiru both recorded their wettest December on record while Darwin Airport and Alice Springs had below average rainfall.

Extremes Records Summaries Important notes the top

Tropical Cyclone Grant

For several days numerical weather prediction models were consistently developing a low off the north coast, however the location and movement was unclear. On Wed 21st, a surface low was identified to the north of the Cobourg Peninsula by satellite observations. During the next few days, multiple vortices developed within a sharp shear line along the monsoon trough with initially, strong, southeast winds feeding in followed by a strengthening monsoon feeding in from the north. The system lacked persistent deep convection and did not develop to tropical cyclone strength for several days. On the 23rd, the low started showing signs of development in the cloud structure, however the system still struggled to maintain persistent development. Overnight on Saturday the 24th, further development occurred and TC Grant was named at 3:30am on Christmas Day, Sunday the 25th.

McCluer Island was the only station that reported gales. Gusts to 35kt were first observed at 4am on the 25th and mean winds of 35kt were first observed at 10am on 25th. These winds steadily increased and at 12pm, storm force winds of 51kt gusting to 61kt were reported. TC Grant then moved in a south southwest direction along the coast over the far eastern Van Diemen Gulf. It was weakening, but maintained as a Category 2 system until early on the 26th. At 6:30am it had crossed the coast again at the southeastern corner of the Van Diemen Gulf as a Category 1 system. By mid-day on the 26th it was downgraded to below TC strength.

Ex-TC Grant moved east over Arnhem Land and re-emerged over the Gulf of Carpentaria and continued eastward over the Cape York Peninsula and then into the Pacific Ocean but did not regain cyclone strength.

Flash Floods

On the 26th, Ex-TC Grant moved southwards, west of Jabiru, then slowed down as it gradually turned southeast and then east overnight on the 26th near Pine Creek. During this time rainfall of over 300 mm fell in the Edith, Cullen, Fergusson and Katherine River Catchments, including 385 mm at Edith River Ridge, resulting in flash flooding along those rivers.

Rainfall

Gove Airport already had above average rainfall for December when the monsoon trough moved over in the last few days of the month giving them their highest total December rainfall on record with 516.4 mm. Jabiru airport was similar, they had already received 378.2 mm of rainfall up to the 23rd of the month, including 87.2 mm on the 4th. And then as ex-TC Grant moved into the region an additional 71 mm fell on the 26th. By the end of the month a total of 459 mm had fallen passing the previous December record of 413.9 which fell in December 1977.

The wettest overall was Ngayawili with 607.8 mm, followed by Edith Falls Ridge with 566.4 mm, and then Warruwi with 559.8 mm.

The wettest single day was on the 27th as ex-TC Grant pushed inland. The highest rainfall totals from this event were Edith Falls Ridge with 385.0 mm, followed by Cullen River with 342.0 mm, and then Upper Seventeen Mile Creek with 311.2 mm.

Some sites, including Centre Island and Fergusson River, had their highest December daily rainfall on record.

Maximum temperature

Between the 3rd and 5th areas of The Barkly and northern Alice Springs districts experienced refreshingly cool days. Daily maximum temperatures were 8-12 degrees below the long term average. Alice Springs Airport measured a maximum temperature of only 26.2 °C on the 3rd which is 9 °C below their monthly average, Curtin Springs measured only 27 °C on the 4th, and Jervois saw a high of only 26.3 on the 4th which is 11.4 °C below their long term average. Temperatures quickly rebounded to near average temperatures for the remainder of the month.

The hottest day was at Yulara Aero with 44.3 °C on the 25th, followed by Ali Curung with 44.1 °C on the 31st, and then Walungurru with 43.2 °C on the 10th.

The warmest days on average were at Rabbit Flat and at Walungurru both with 37.8 °C, followed by Lajamanu with 37.7 °C, and then Ali Curung with 37.5 °C.

The coolest days on average were at Black Point with 32.1 °C, followed by Ngayawili with 32.2 °C, and then Alyangula Police and Central Arnhem Plateau which both had 32.4 °C.

The coldest day was at Tennant Creek Airport with 24.4 °C on the 3rd, and at Central Arnhem Plateau which also had 24.4 °C but on the 27th. These were followed by Papunya with 25.0 °C on the 14th, and then Tindal RAAF with 25.1 °C on the 26th, and Borroloola which also had 25.1 °C on the 27th.

Channel Point and Port Keats Aero both measured their highest December temperature on record. A few other temperature records include Tindal RAAF and Borroloola which had their coldest December day (lowest maximum temperature) on record. Alyangula Police their lowest December mean daily maximum temperature on record.

Minimum temperature

Minimum temperatures were average to above average along the north coast and in the Alice Springs District, but were below average across central NT. When averaged across the Territory, the monthly mean minimum temperature was 17.4 °C which is 1.1 °C below average. Black point had their lowest December temperature on record with 20.1 °C on the 27th breaking the old record of 21.2 set on the 30th in 1996. Channel Point tied their highest December mean daily minimum temperature on record with 25.8 °C which ties their record set in December 2000. Four sites, including Rabbit Flat and Timber Creek, had their lowest December mean daily minimum temperature on record.

The coldest night was at Kulgera with 10.5 °C on the 2nd, followed by Arltunga with 12.0 °C on the 7th, followed by Kulgera with 12.8 °C on the 1st.

The coolest nights on average were at Arltunga and Kulgera which both had an average minimum temperature of 18.9 °C. The next coolest places were Alice Springs Airport and Yulara Aero which both had 19.1 °C, and then Curtin Springs with 19.2 °C.

The warmest nights on average were at Cape Don with 27.5 °C, followed by Centre Island with 26.8 °C.

The warmest night was at Ngayawili with 29.9 °C on the 10th followed by Centre Island with 29.8 °C on the 11th.

Wind

The strongest wind gust was at McCluer Island with 126 km/h as TC Grant made landfall on the 25th, followed by Rabbit Flat with 107 km/h on the 11th, followed by Yulara Aero with 98 km/h on the 21st.

---

Extremes in December 2011
Hottest day	44.3 °C at Yulara Aero on the 25th
Warmest days on average	37.8 °C at Rabbit Flat 37.8 °C at Walungurru
Coolest days on average	32.1 °C at Black Point
Coldest day	24.4 °C at Tennant Creek Airport on the 3rd 24.4 °C at Central Arnhem Plateau on the 27th
Coldest night	10.5 °C at Kulgera on the 2nd
Coolest nights on average	18.9 °C at Arltunga 18.9 °C at Kulgera
Warmest nights on average	27.5 °C at Cape Don
Warmest night	29.9 °C at Ngayawili on the 10th
Warmest on average overall	30.9 °C at Walungurru
Coolest on average overall	26.6 °C at Arltunga
Wettest overall	607.8 mm at Ngayawili
Wettest day	385.0 mm at Edith Falls Ridge on the 27th
Highest wind gust	126 km/h at McCluer Island on the 25th

Extremes Records Summaries Important notes the top

---

Record highest December daily rainfall
	Highest daily rainfall in December 2011 (mm)		Previous wettest for December		Years of record
Centre Island	146.0	on the 28th	137.0	on the 26th in 2000	44
Mary River Rangers	192.8	on the 27th	155.1	on the 28th in 1993	23
North East Island	95.0	on the 23rd	94.0	on the 12th in 1993	21
Cape Wessel	148.8	on the 24th	66.0	on the 21st in 2003	20
Nitmiluk Rangers	184.6	on the 27th	157.0	on the 22nd in 2003	15
Fergusson River	144.4	on the 27th	96.8	on the 22nd in 2010	12
Seventeen Mile Creek	184.5	on the 27th	127.5	on the 22nd in 2003	12

---

Record highest total December rainfall
	Total rainfall for December 2011 (mm)	Previous wettest for December		Years of record	Average for December
Gove Airport	516.4	372.6	in 1999	35	174.1
Jabiru Airport	459.0	413.9	in 1977	33	227.0
Yirrkala Tropical Gardens	549.0	338.0	in 1992	22	136.4
North East Island	419.6	283.0	in 1993	19	76.8
Ngayawili	607.8	574.0	in 2003	11	249.4

---

Record highest December temperature
	Highest temperature in December 2011 (°C)		Previous warmest for December		Years of record	Average for December
Channel Point	35.7	on the 25th	35.4	on the 16th in 2004	16	32.3
Port Keats Aero	38.9	on the 25th	37.9	on the 6th in 2006	10	33.4

---

Record lowest December daily maximum temperature
	Lowest daily maximum temperature in December 2011 (°C)		Previous coolest for December		Years of record	Average for December
Larrimah	26.0	on the 27th	26.1	on the 6th in 2000	44	36.8
Tindal RAAF	25.1	on the 26th	26.1	on the 22nd in 2003	22	35.6
Borroloola	25.1	on the 27th	26.1	on the 31st in 2001	16	36.5
McCluer Island	28.9	on the 22nd	= 28.9	on the 11th in 2009	11	32.1
Ngayawili	27.3	on the 23rd	28.7	on the 28th in 2007	11	32.7

---

Record lowest December mean daily maximum temperature
	Mean daily maximum temperature for December 2011 (°C)	Previous coolest for December		Years of record	Average for December
Alyangula Police	32.4	= 32.4	in 2000	28	33.9

---

Record lowest December temperature
	Lowest temperature in December 2011 (°C)		Previous coolest for December		Years of record	Average for December
Black Point	20.1	on the 27th	21.2	on the 30th in 1996	18	26.2

---

Record highest December mean daily minimum temperature
	Mean daily minimum temperature for December 2011 (°C)	Previous warmest for December		Years of record	Average for December
Channel Point	25.8	= 25.8	in 2000	16	25.0

---

Record lowest December mean daily minimum temperature
	Mean daily minimum temperature for December 2011 (°C)	Previous coolest for December		Years of record	Average for December
Timber Creek	24.4	24.6	in 2000	29	25.4
Borroloola	24.2	= 24.2	in 2000	16	25.4
Rabbit Flat	22.4	22.6	in 2000	14	23.7
Port Keats Aero	24.8	= 24.8	in 2006	10	25.7

Extremes Records Summaries Important notes the top

---

Summary statistics for December 2011
	Maximum temperatures (°C)				Minimum temperatures (°C)				Rainfall (millimetres)
	Mean	Diff from average	Highest		Mean	Diff from average	Lowest		Total	Average	Rank	Fraction of average
Darwin-Daly (district 14GA)
Batchelor Aero	34.3	+0.6	36.8	10th	24.2	+0.1	20.6	2nd	149.2	280.6	low	53%
Black Point	32.1	-0.3	34.4	7th	26.3	+0.1	20.1	27th	498.6	208.8	v high	239%
Bradshaw	36.5	0.0	39.6	1st	24.9	-0.6	21.4	2nd	89.0	170.4	average	52%
Cape Don	32.9		35.1	16th	27.5		23.3	12th	311.2	265.4	average	117%
Central Arnhem Plateau	32.4		36.9	14th	23.3		20.9	27th	212.0
Channel Point	33.3	+1.0	35.7	25th	25.8	+0.8	22.0	2nd	67.8	331.9	v low	20%
Darwin Airport	33.3	+0.7	35.0	28th	25.7	+0.4	22.4	2nd	234.2	250.4	average	94%
Delamere Weapons Range	35.4	-0.3	38.7	31st	24.0	-0.5	20.7	4th	156.8	175.2	average	89%
Douglas River	35.0	0.0	37.5	14th	24.3	+0.7	22.5	2nd	170.6	204.2	average	84%
Dum In Mirrie AWS	33.2	+0.8	34.5	21st	26.4	+0.3	23.0	2nd	159.8	288.2	low	55%
Jabiru Airport	34.2	-0.8	37.1	10th	25.0	+0.1	23.2	14th	459.0	227.0	highest	202%
Mango Farm	35.5	+0.7	38.4	31st	24.1	+0.3	21.9	15th	167.0	243.7	average	69%
Middle Point AWS	34.7		36.7	14th	24.1		22.6	4th	213.6
Noonamah AWS	35.0		36.9	14th	24.2		22.6	5th	365.6
Oenpelli	34.0	-0.9	36.8	14th	24.7	+0.2	22.1	26th	484.0	224.6	v high	215%
Pirlangimpi	33.3	+0.7	35.7	4th	25.2	+0.5	22.1	13th	427.4	350.4	high	122%
Point Stuart AWS	32.7		34.8	11th	25.0		22.6	2nd	178.4	205.5	average	87%
Port Keats Aero	34.8	+1.4	38.9	25th	24.8	-0.9	22.3	5th	132.8	146.4	average	91%
Tindal RAAF	35.3	-0.3	38.9	14th	24.6	-0.2	21.7	27th	218.0	201.3	high	108%
Arnhem (district 14BC)
Alyangula Police	32.4	-1.5	35.6	11th			21.5	31st	376.8	163.3	v high	231%
Cape Wessel	33.3		36.2	14th			24.3	25th	385.8	121.6	v high	317%
Gove Airport	33.0	+0.1	37.6	11th	24.9	+0.3	23.4	23rd	516.4	174.1	highest	297%
Groote Eylandt Airport AWS	33.4	-0.9	36.8	30th	25.1	0.0	23.3	6th	304.8	189.0	v high	161%
Ngayawili	32.2	-0.5	34.7	4th	25.9	+0.3	23.2	5th	607.8	249.4	highest	244%
North East Island	32.9		35.7	16th	26.7		23.9	23rd	419.6	76.8	highest	546%
Warruwi	32.8	-0.4	34.6	15th	25.9	-0.3	23.7	12th	559.8	191.9	v high	292%
Roper-Mcarthur (district 14DE)
Borroloola	34.5	-2.0	38.8	10th	24.2	-1.2	19.7	4th	316.8	127.2	high	249%
Centre Island	33.7	-0.9	37.1	10th	26.8	-0.6	22.7	4th	466.2	124.1	v high	376%
Daly Waters AWS	35.3	-2.0	39.0	31st	23.2	-1.1	17.8	30th	89.2	104.9	average	85%
Larrimah	35.1	-1.7	38.2	10th	23.8	-0.7	20.5	4th	147.0	137.7	average	107%
McArthur River Mine	36.0	-1.8	40.3	10th	24.8	-0.1	19.6	4th	194.6	119.3	high	163%
Ngukurr	35.8	-2.2	39.6	10th	25.5	0.0	22.1	4th	152.0	130.0	average	117%
Wollogorang	35.6	-1.2	39.5	14th	23.4	-0.8	20.0	9th	66.6	162.1	low	41%
Victoria (district 14F)
Kidman Springs	36.6	-0.9	40.3	25th	25.0	-0.4	21.5	3rd	94.7	137.9	low	69%
Lajamanu	37.7	-0.3	41.6	31st	23.6	-0.6	19.4	4th	87.6	75.3	average	116%
Timber Creek	36.4	-0.8	39.5	25th	24.4	-1.0	21.0	4th	148.9	177.7	average	84%
Victoria River Downs	36.4	-1.4	40.7	31st	24.5	-0.6	21.6	3rd	115.2	117.2	average	98%
Wave Hill	36.9	-1.3	41.2	31st	23.6	-0.9	18.8	30th	89.1	117.2	average	76%
Barkly (district 15A)
Brunette Downs	36.9	-1.6	40.4	31st	23.6	-0.8	19.3	5th	37.4	67.1	average	56%
Elliott	35.9	-2.8	39.4	31st	23.8	-0.6	18.5	30th	136.9	95.4	high	144%
Tennant Creek Airport	35.4	-1.9	39.9	11th	23.6	-1.3	17.8	4th	105.0	67.4	high	156%
Alice Springs (district 15B)
Ali Curung	37.5	-0.3	44.1	31st			17.5	5th	22.6	63.8	low	35%
Alice Springs Airport	36.4	+1.0	42.2	25th	19.1	-1.1	13.2	5th	3.6	37.1	low	10%
Arltunga	34.6	+0.3	40.6	10th	18.9	-1.5	12.0	7th	21.8	40.0	average	55%
Curtin Springs	35.6	-0.7	42.9	25th	19.2	-1.3	13.0	5th	22.5	29.8	average	76%
Jervois	36.6	-1.2	41.4	10th	21.1	-0.2	15.8	5th	28.8	38.7	average	74%
Kulgera	34.9	-0.1	42.3	25th	18.9	-1.5	10.5	2nd	12.7	34.5	average	37%
Papunya	35.2		40.5	31st	21.1		15.0	4th	63.3	33.0	high	192%
Rabbit Flat	37.8	-0.6	42.5	11th	22.4	-1.3	16.6	4th	73.8	79.5	average	93%
Territory Grape Farm	36.5	+0.2	41.2	10th	22.1	+1.1	17.6	4th	57.6	45.0	average	128%
Walungurru	37.8		43.2	10th	23.9		16.8	4th	57.0
Yulara Aero	35.4	-0.9	44.3	25th	19.1	-1.6	13.9	6th	57.8	43.5	average	133%
Offshore Islands (district 200)
Northern Endeavour	34.1	+0.6	36.0	6th	28.1	0.0	25.0	11th

Extremes Records Summaries Important notes the top

---

---