Weekly update - 04 May 2017

During the week ending 3 May 2017 little to no rainfall was recorded across the majority of Australia, with isolated areas of eastern New South Wales, southern Victoria, western Tasmania, northern Western Australia and the Top End of the Northern Territory recording some useful falls. The highest recorded weekly total was 234 millimetres on Tiwi Island, north of Darwin in the Northern Territory.
The Top End of the Northern Territory has recorded the third-wettest wet season (1 November 2016 – 30 April 2017) on record. The 2016-2017 wet season recorded 2,484.4 millimetres of rainfall in Darwin, well above the average of 1,700 millimetres. The above average falls have boosted groundwater and surface water supplies and resulted in solid pasture growth with strong prospects heading into the dry season.

The rainfall analyses and associated maps utilise data contained in the Bureau of Meteorology climate database, the Australian Data Archive for Meteorology (ADAM). The analyses are initially produced automatically from real-time data with limited quality control. They are intended to provide a general overview of rainfall across Australia as quickly as possible after the observations are received.

For further information go to Weekly Rainfall Update

Rainfall - week ending 3 May 2017

 

©Commonwealth of Australia 2017, Australian Bureau of Meteorology - Issued: 03/05/2017

Rainfall for April 2017 was extremely high in south-western areas of New South Wales and the eastern half of Victoria, extending through most of South Australia into the central-east of Western Australia and the south-west corner of the Northern Territory. There were scattered areas along the northern coast of Western Australia and the Top End of the Northern Territory and Far North Queensland that also recorded extremely high rainfall. Rainfall was extremely low to severely deficient in the south-east Queensland, south-western Western Australia and western Tasmania.

In cropping regions, April rainfall was mostly average in New South Wales, severely deficient to average in Queensland and Western Australia and average to extremely high in Victoria and South Australia.

Rainfall percentiles for April 2017

Source: Bureau of Meteorology

Note: Spatial rainfall percentile analyses are based on historical monthly rainfall data provided by the Bureau of Meteorology. These rainfall percentile maps show how rainfall recorded during that given time period compared with the rainfall recorded for that same period during the entire historical record (1900 to present). Rainfall percentiles are a way of providing an indication of the spread of data in a data set. To calculate percentiles, the entire rainfall record at a certain point is divided into one hundred equal parts. The 5th percentile for April 2017 means that only five per cent of all Aprils in the historical record have recorded a rainfall total that is at or below the rainfall recorded during April 2017. Dark blue areas on the maps are those areas that were wetter than the same time of year during the entire historical record, and dark red areas are drier. For further information, go to http://www.bom.gov.au/jsp/awap/

The forecast for the next eight days indicates that little to no rainfall is forecast for most of mainland Australia. Rainfall totals exceeding 25 millimetres are expected along coastal Queensland and in western Tasmania.

This rainfall forecast is produced from computer models. As it contains no input from weather forecasters, it is important to check local forecasts and warnings issued by the Bureau of Meteorology.

Total forecast rainfall (mm) for the period 4 to 11 May 2017

 

©Commonwealth of Australia 2017, Australian Bureau of Meteorology - Issued: 04/05/2017

During the week ending 2 May 2017 maximum temperatures were generally below average across much of the country, with parts of southern Australia recording temperatures between 4°C and 6°C below average. Minimum temperatures were generally below average across most of Australia. Parts of central New South Wales, Queensland and Western Australia recorded minimum temperatures between 4°C and 6°C below average for this time of year.

Maximum temperature anomalies - week ending 2 May 2017

 

©Commonwealth of Australia 2017, Australian Bureau of Meteorology - Issued: 2/05/2017

Minimum temperature anomalies - week ending 2 May 2017

 

©Commonwealth of Australia 2017, Australian Bureau of Meteorology - Issued: 2/05/2017

Note: Spatial temperature analyses are based on historical weekly temperature data provided by the Bureau of Meteorology. These temperature anomaly maps show the departure of the maximum and minimum temperatures from their long-term averages. Temperature anomalies are calculated using high-resolution gridded datasets from 1911 onwards. For further information go to Daily maximum temperature for Australia.

The maps below show the levels of modelled upper layer (0 to 10 centimetres) soil moisture and lower layer (10 centimetres to 1 metre) soil moisture during April 2017. These maps show how modelled soil conditions during April 2017 compare with April conditions modelled over the 106 year reference period (1911 to 2016). Dark blue areas on the maps are those areas that were much wetter than the same time of year during the reference period, and dark red areas were much drier than during the reference period. These data are from the Australian Water Resources Assessment Landscape model (AWRA-L version 5.0), which was developed through the Water Information Research and Development Alliance (WIRADA) initiative. WIRADA is a collaborative project between the BoM and the CSIRO.

The bulk of plant roots occur in the top 20 centimetres of the soil profile. Soil moisture in the upper layer of the soil profile (10 centimetres) is therefore the most appropriate indicator of the availability of water, particularly for germinating plants. The lower layer soil moisture is a larger, deeper store that is slower to respond to rainfall and tends to reflect accumulated rainfall events over longer time periods.

Relative upper layer soil moisture for April 2017 was well above average to extremely high in a band covering northern Western Australia, South Australia, southern New South Wales and Victoria. The relative upper layer soil moisture was well below average to extremely low in central and western Queensland and adjacent areas of the Northern Territory, western Tasmania and south-western Western Australia. The pattern of relative upper layer soil moisture reflects rainfall received during April 2017.

Modelled upper layer soil moisture for April 2017

Source: Bureau of Meteorology (Australian Water Resources Assessment Landscape model)

Relative lower layer soil moisture for April 2017 was well above average to extremely high in eastern New South Wales and western Victoria, northern and south-eastern Queensland and across most of Western Australia, and the Top End of the Northern Territory. Lower layer soil moisture for April 2017 was well below average to extremely low in a large area of central Australia, across most of western Queensland and adjacent areas of Northern Territory, scattered areas of north-western New South Wales, north-eastern and southern South Australia and parts of Western Australia.

Modelled lower layer soil moisture for April 2017

Source: Bureau of Meteorology (Australian Water Resources Assessment Landscape model)

Water storage levels in the Murray–Darling Basin (MDB) decreased during the week ending 4 May 2017 by 267 gigalitres (GL) to 15,331 GL and are at 68 per cent of total capacity. This is 38 percentage points or 8,679 GL more than at the same time last year.

Water storages in the Murray-Darling Basin (NSW, Victoria and Queensland)

 

Information on irrigation water available in the Murray–Darling Basin from 1 January 2001 to 4 May 2017 is shown above. The top horizontal (short dash) line indicates the storage level during a similar time last year. The bottom horizontal (long dash) line indicates the amount of ‘dead’ or unusable storage.

Water storages

Changes in regional water storage for April 2017 and the previous 12 months are summarised in the table and graph below (current at 4 May 2017).

Region	Total capacity	Current volume	Current volume	Monthly change	Monthly change	Annual change
	(GL)	(GL)	(%)	(GL)	(%)	(GL)
Murray-Darling Basin (MDB)	22,598	15,331	68	-192	-1	8,679
Murray-Darling Basin Authority (MDBA)	9,352	5,716	58	-93	-1	3,475
Queensland MDB	186	178	96	1	1	72
Central Queensland	3,154	2,792	87	-243	-8	92
South-east Queensland	3,517	2,397	68	-57	-2	96
New South Wales MDB	13,884	8,791	63	-168	-1	5,434
Coastal New South Wales	1,074	953	89	-2	0	42
Victoria MDB	8,488	6,151	72	-25	0	2,962

Water storages in the Murray-Darling Basin by state (NSW, Victoria and Queensland)

 

Wheat

A large snowstorm and strong winds swept across the US plains wheat belt on 29 and 30 April. While the extent of damage is still being assessed, early reports indicate winter wheat crops have been affected in Kansas, Colorado, Oklahoma and Nebraska. These states are estimated to account for almost half of the total area planted to US winter wheat in 2017. Winter wheat crops are susceptible to damage because of their current stage of development. Corn and soybean crops are less vulnerable because they are in the planting and emergence stage of development.

Dairy

The price of anhydrous milk fat (AMF) rose 4 per cent to US$6,185 a tonne at the Global Dairy Trade (GDT) auction event on 2 May 2017, while the price of skim milk powder fell by 3 per cent to US$1,982 a tonne. The ratio of AMF to skim milk powder is currently at the highest level since these products began trading on the GDT in 2010 (Figure 1). This divergence of milk fat to solids‑not‑fat follows large exportable surpluses of skim milk powder, particularly in the European Union, and strong global demand for milk fat.

Figure 1 Ratio of AMF and SMP prices on GDT, March 2010 to April 2017

Source: Global Dairy Trade

• Selected world indicator prices
• Global dairy trade weighted average prices
• Selected domestic crop indicator prices
• Selected domestic livestock indicator prices
• Movements in selected fruit and vegetable prices
• Data attribution