Tuesday, 1 May 2012 - Monthly Climate Summary for South Australia - Product code IDCKGC13R0
South Australia in April 2012: A warm, dry start to the Growing Season
- Rainfall was average to below across most of the State, with very much below average totals across eastern parts of the State.
- Warm days with maximum temperatures in excess of 1 °C, though cool nights for eastern parts of the State.
South Australia received less than half of the average April rainfall for the State as a whole. Apart from the far northwest of State, where rainfall totals were slightly above average, most of South Australia reported below average to very much below average rainfall. See a map of rainfall deciles.
The wettest period across South Australia during April 2012 was between the 21st and 26th as a low pressure system located in the Great Australian Bight extended a trough of low pressure across the State. A cold frontal system followed, moving across parts of the agricultural areas ahead of a moist south to southwesterly airstream being directed across southern coastal districts.
The growing season, for cropping farming in agricultural districts, is typically viewed as starting in April, often with a significant rain event occurring towards the end of April as the break to the season. This year, a cold front in the third week of the month saw rainfall totals of 25mm or greater in a 3 day period across lower Eyre and Yorke Peninsulas, parts of the Mount Lofty Ranges and across Kangaroo Island, but other areas did not see a definite break to the growing season occur in April 2012.
While some locations in the Northwest received rainfall totals ranging between 20 and 40mm, most parts of the Pastoral districts were average to well below average for April 2012. Totals generally ranging between 5 to 15 mm across the Northeast and Far North, though several locations reported no rainfall for the month. Ernabella (Pukatja), in the Northwest, was the wettest location in the Pastoral districts, reporting 24 mm for the month.
Rainfall totals for April 2012 over Eyre and Yorke Peninsulas, Kangaroo Island, parts of the Mount Lofty Ranges and the Southeast districts were mostly average tending to below average over the Flinders Ranges and the Upper North, with totals generally ranging between 20 to 40mm. Rainfall totals of between 10 to 20mm were recorded over southern coastal areas grading to lesser values further inland. The wettest location for the State overall was at Aldgate Creek where 62.2mm of rainfall was recorded for the month.Some sites had their lowest total April rainfall on record.
The average temperature (the average of the daily maximum and daily minimum temperatures) for South Australia as a whole in April 2012 was 0.7 °C above the long-term April average; as opposed to the below average April mean temperature in 2011. All parts of the State, apart from the far Northwest Pastoral district, saw above average temperatures in April 2012. In particular, coastal regions in the western and southeastern agricultural districts reported average temperatures in excess of 1 °C above normal, much of the rest of the State reported slightly above average temperatures.
The maximum temperature averaged across the whole State was 1 °C above the long-term April average, being close to average across large areas of the northern parts of the State, grading to 1 to 2 °C above average over the coastal regions. See a map of maximum temperature anomalies. The warmest period of the month occurred through the first week of April as warm northerly winds were directed across the State ahead of the passage of a low pressure surface trough. This saw temperatures up to 6 °C warmer than average through the first week of the month.
The hottest day of the month for any location was recorded at Tarcoola Aerodrome on the 2nd where the maximum temperature reached 40.0 °C. Mount Lofty had the coldest day on the 23rd with a maximum of 9.5°C being recorded.
Minimum temperatures for the month were generally slightly greater than average for most of South Australia, averaging 0.3 °C above normal for the State as a whole. Minimum temperatures tended to 1°C above average across most parts of the State, while areas east of the Flinders Ranges, the Upper North and Upper Murray Valley recorded minimums below average. See a map of minimum temperature anomalies. Values across the State for the month as a whole ranged from 7.1°C at Yongala in the Upper North to16.1 °C at Neptune Island.
The coolest nights for many locations were between the 11th and 13th and again between the 24th and 28th of April. The coldest night for any location was recorded in the earlier period at Gluepot Reserve (Gluepot) where a minimum of -0.1 °C was recorded on the 12th; owing to the influence of a high pressure system centred to the Southeast of the State which resulted in cool and clear conditions.
The warmest nights of the month for many locations in South Australia occurred through the first week of the April as a warm northwesterly airstream was directed across the State ahead of a low pressure trough. Marla Police Station recorded the warmest night of the month with a minimum temperature of 25.5°C on April 2nd.Some sites had their warmest April night (highest daily minimum temperature) on record.
|Extremes in April 2012|
|Hottest day||40.0 °C at Marla Police Station on the 2nd|
|Warmest days on average||29.3 °C at Marree Comparison|
|Coolest days on average||18.6 °C at Mount Lofty|
|Coldest day||9.5 °C at Mount Lofty on the 23rd|
|Coldest night||-0.1 °C at Gluepot Reserve (Gluepot) on the 12th|
|Coolest nights on average||7.0 °C at Yongala|
|Warmest nights on average||16.1 °C at Neptune Island|
|Warmest night||25.5 °C at Marla Police Station on the 2nd|
|Warmest on average overall||21.8 °C at Oodnadatta Airport|
|Coolest on average overall||14.8 °C at Mount Lofty|
|Wettest overall||62.2 mm at Aldgate Creek|
0 mm at Andamooka|
0 mm at Arkaroola
0 mm at Clare (Neagles Rock)
0 mm at Gammon Ranges (Arcoona Bluff)
0 mm at Leigh Creek (Maynards Well)
0 mm at Leigh Creek Airport
0 mm at Marree Aero
0 mm at Marree Comparison
0 mm at Moomba Airport
0 mm at South Para Resv (Saw)
|Wettest day||42.0 mm at Aldgate Creek on the 23rd|
|Highest wind gust||98 km/h at Cape Willoughby on the 6th|
|Record lowest total April rainfall|
for April 2012 (mm)
|Marree Comparison||0.0||= 0.0||in 2011||127||10.8|
|Arkaroola||0.0||= 0.0||in 2004||75||14.4|
|Andamooka||0.0||= 0.0||in 1997||47||15.1|
|Leigh Creek Airport||0.0||= 0.0||in 1999||26||13.4|
|Record highest April daily minimum temperature|
Highest daily minimum
in April 2012 (°C)
|Andamooka||24.1||on the 6th||23.3||on the 2nd in 2005||43||13.9|
|Marla Police Station||25.5||on the 2nd||25.4||on the 5th in 1992||26||13.6|
|Whyalla Aero||23.2||on the 6th||22.7||on the 14th in 2004||25||11.7|
|Summary statistics for April 2012|
|Northwest (district 16)|
|Coober Pedy Airport||27.3||38.0||5th||14.6||7.2||11th||5.2|
|Roxby Downs (Olympic Dam Aerodrome)||27.6||37.6||2nd||11.2||2.7||11th||0.2|
|Far North (district 17)|
|Leigh Creek Airport||27.0||+0.8||35.5||2nd||12.5||-0.4||6.5||28th||0||13.4||lowest||0%|
|Western Agricultural (district 18)|
|Coulta (Coles Point)||23.0||+0.9||30.8||20th||12.1||+0.3||6.7||16th||40.6|
|North Shields (Port Lincoln AWS)||24.0||+2.0||33.2||2nd||12.1||0.0||7.6||13th||23.6|
|Port Augusta Aero||27.5||38.2||2nd||12.1||4.7||11th||0.4|
|Upper North (district 19)|
|Northeast (district 20)|
|Gluepot Reserve (Gluepot)||25.8||34.0||2nd||8.1||-0.1||12th||2.2|
|Lower North (district 21)|
|Clare High School||23.0||32.2||5th||9.2||4.2||28th||15.4|
|Port Pirie Aerodrome||26.1||36.5||2nd||10.9||4.6||24th||8.6|
|Port Pirie Nyrstar Comparison||26.0||+1.2||35.5||5th||14.2||+1.0||8.9||24th||7.6||27.5||low||28%|
|Snowtown (Rayville Park)||25.5||35.3||2nd||10.0||4.6||12th||8.2|
|Yorke Peninsula (district 22A)|
|Kangaroo Island (district 22B)|
|Parndana Cfs AWS||22.0||31.8||5th||10.7||6.8||13th||50.6|
|Adelaide Plains (district 23A)|
|Adelaide (Kent Town)||24.2||+1.6||34.6||5th||12.6||+0.2||7.6||24th||27.0||40.1||average||67%|
|County Light (district 23B)|
|Rosedale (Turretfield Research Centre)||25.1||+2.0||34.8||2nd||10.9||+0.2||4.4||24th||9.2||36.4||low||25%|
|Mount Lofty Ranges (district 23C)|
|Hindmarsh Island AWS||22.9||33.5||5th||12.8||7.4||11th||19.2|
|Kuitpo Forest Reserve||20.9||30.7||5th||12.1||6.7||11th||43.8|
|Mount Crawford (Mt Crawford AWS)||20.8||30.3||5th||12.0||5.0||11th||14.0|
|Parawa (Second Valley Forest AWS)||20.0||30.0||5th||12.2||8.4||24th||51.0|
|Victor Harbor (Encounter Bay)||22.6||32.5||2nd||10.3||2.5||13th||21.8|
|Upper Murray Valley (district 24A)|
|Loxton Research Centre||25.2||+1.3||33.4||6th||8.4||0.0||1.4||12th||8.6||15.9||average||54%|
|Lower Murray Valley (district 24B)|
|Murray Bridge (Pallamana Aerodrome)||24.8||34.7||2nd||8.9||1.9||12th||16.4|
|Murray Bridge Comparison||25.3||+1.8||34.3||5th||10.5||+0.3||4.5||12th||24.9||28.8||average||86%|
|Murray Mallee (district 25A)|
|Upper Southeast (district 25B)|
|Lameroo (Austin Plains)||24.3||33.4||6th||8.8||2.6||11th||12.6|
|Lower Southeast (district 26)|
|Cape Jaffa (The Limestone)||21.1||+1.3||28.2||5th||11.3||+0.8||5.8||12th||48.6|
|Mount Gambier Aero||22.0||+2.6||29.9||5th||9.4||+0.7||2.7||12th||39.6||54.8||average||72%|
A Monthly Climate Summary is prepared to list the main features of the weather in South Australia 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 10 am on Tuesday 1 May 2012. 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
all available years of record, which vary widely from site to site.
They are not shown for sites with less than 20 years of record, 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.