The Break Newsletter
Seasonal climate and risk information for Victorian cropping regions
Volume 6/Issue 2 March 2011 | www.dpi.vic.gov.au/climaterisk | ISSN 1833-719
This Issue
- State Round Up
- Seasonal Outlook
- La Nina/IOD negative years
- Mallee
- Wimmera
- North East
- South West
- The Fiver
Break Out Season
Hi! Here at The Break editorial desk we feel we have witnessed a break out season. After years of talking droughts, half optimistic winters, followed by heartbreak springs, we finally had a year where winter and spring was kind to most. Who would have guessed summer could bring such pain. The reality of farming in Australia is a series of climatic challenges that keeps everyone on their toes. Many people seem to want the weather to go back to normal. But what is normal? Normal is some wet days, some dry days, some cold days and some hot days. We have had them all this summer. It’s just that we had too many wet days for most people’s liking.
A good thing to come out of the season so far is that it has reinforced the power of the oceans and their impact on our weather and climate. The La Nina has, in many scientists’ eyes, been the biggest on record with an unprecedented wet summer. Mind you we only have 100 odd years of data collected and when I drive through Northern Victoria I see some of those river channels quite deep and wide. I am always reminded that the Wimmera system is part of the Murray Darling basin, and did fl ow into the Murray at one stage in earlier geological times.
The very wet conditions and stubble residue from 2010 might make sowing a major challenge. Many growers will be exploring all the tools they have available including both the use of discs and matches. Each tool has its costs but needs to be evaluated as part of each person’s total system. Ensuring the crops have appropriate fertiliser at the right time is another challenge; a wet start may bring along both weed and disease control issues. Seed which is slightly weather damaged may not handle products like trifl uralin or some of the seed and fertiliser dressings used to control diseases. Seed germination and vigour testing becomes important.
I recommend an “Ask your Dad” session! He was farming in the mid seventies when it was wet, while the last 10 years has been all about managing risk when the dryness was at top of mind. Chewing over the fat with Dad is always a worthwhile exercise whether you learn heaps or nothing much; and an investment in thinking through the options could well be worthwhile.
Here’s hoping for a normal 2011!
State Round Up-In the paddock
Mallee: GSR Decile (10)
Summer/autumn weed control, stubble management (including selective burning), soil sampling, and grain quality assessments for sowing are in full swing with increasing mice numbers looking on in glee! A large planting of early canola is planned at the expense of pulses and maybe barley. Initial soil test results are generally very low in nitrogen but full to capacity of moisture. An early “in-crop” soil retest will be advised to confirm such low N results.
Wimmera: GSR Decile (10)
A full profile of moisture has lead to large numbers of summer weeds that people are only now having the chance to get under control after the long harvest and poor spraying weather. Stubble loads are a concern and some are already starting to work paddocks to ensure ease of sowing, others are confident that they will be able to retain stubble. Conditions are not yet right for burning.
North East: GSR Decile (10)
More rain this week and the locals are getting restless about a wet start. Full profiles, heavy stubbles and rampant weeds. Plenty of summer spraying in the last month and plenty of burning since the restrictions went off suggest that many people are concerned about getting their crops established with the current stubble loads.
South West: GSR Decile (3-10)
Harvest still progressing 80% complete, now all feed quality, delayed by frequent rain events, poor trafficability, full moisture profiles, some early winter wheat sowings planned. Plenty of weed control issues. Some stubble burning has occured under permit.
Gippsland: Summer Decile (6-8)
Winter weeds are germinating, soil moisture is good. Some farmers will start planting early winter wheats and fodder crops now, but most are waiting until April. Stubbles aren’t too heavy, burning conditions are still poor.
Dam Capacity
Grampians Wimmera Mallee 59.4%
Goulburn-Murray: Dartmouth 61.5%, Hume 96.9%, Eildon 82%, Eppalock 100%
NSW: Eucumbene 33.8%, Burrinjuck 96%, Menindee 92%
Seasonal Outlook
Summary: Tropical Pacific Ocean warms (16th March)
www.bom.gov.au/climate/enso/The La Niña event in the Pacific Ocean has continued to weaken over the past two weeks as Pacific Ocean temperatures along the equator have warmed. All available climate models suggest further weakening of the La Niña is likely through the southern hemisphere autumn, with a return to neutral conditions likely by winter 2011.
Current observations of warming in the Pacific Ocean are consistent with the life cycle of past La Niña events. In some contrast to the weakening in the ocean, atmospheric indicators of the La Niña, including trade winds, cloudiness and the Southern Oscillation Index (SOI) remain consistent with a well developed La Niña event. These atmospheric indicators are expected to return to neutral over the coming months.
During La Niña events, tropical cyclone numbers are typically higher than normal during the November to April period, with February and March the peak. The infl uence of La Niña on Australian rainfall and temperature typically peaks during winter to mid-summer, and then weakens during the following autumn. The infl uence of the Indian Ocean Dipole (IOD) on Australian rainfall is limited during the months from December through to April.
SOI: Southern Oscillation Index
http://www.bom.gov.au/climate/enso/
SOI: Is the air pressure difference between Tahiti and Darwin.
The SOI has been consistently positive since July indicating that the Walker Circulation (wind patterns over the equator region of the Padific Ocean) is enhanced. This is indicative of La Nina conditions.
SST: Sea Surface Temperature Anomalies
http://www.osdpd.noaa.gov/ml/ocean/sst/anomaly.html
SST’s in the central Pacific have recently warmed to neutral conditions. The Coral Sea has warmed after Cyclone Yasi stirred it up. The Timor Sea is cooler, where the Indian Ocean off Carnarvon remains warmer.
Sub-surface Sea Temperatures
www.bom.gov.au/oceanography/oceantemp/pastanal.shtml
The sub-surface Pacific Ocean equatorial temperature anomaly continues to remain cooler than average at depth but is on a neutralising warming trend. Some heat was lost during February and this is continuing in March.
ENSO Forecast Models - POAMA
www.bom.gov.au/climate/ahead/ENSO-summary.shtml
The POAMA model in the NINO 3.4 region predicts ocean temperatures to slowly rise into neutral levels for most of the growing season, but tending close to the El Nino threshold in Spring.
Widespread flooding in 2010-11 compared with other years
By Blair Trewin, Climate Analyst BoM, b.trewin@bom.gov.au
Flooding has been exceptionally widespread in eastern Australia during late 2010 and early 2011. Queensland has been the worst-aff ected state, but all four eastern states have seen major flooding at various times since September.
The last time flooding was seen in eastern Australia on a comparable scale was in the early months of 1974. Both times, major flooding in and around Brisbane arose from events relatively localised in southeast Queensland and somewhat separated from more general flooding. While the summer of 1974 was wetter than normal further south, it took until April and May before the most serious flooding aff ected southern New South Wales, Victoria and Tasmania. A number of substantial floods occurred in the coastal rivers of northern New South Wales and a more localised event in late March resulted in the Tasmanian State daily rainfall record being set at Cullenswood, near St. Marys.
1950 and 1956 were actually wetter in eastern Australia than 1974, which turned relatively dry in its second half. Both years saw extensive flooding, with 1950 ranking alongside 1974 as the most significant Lake Eyre fillings of the century and 1956, the year of the lower Murray’s largest flood of the last 100 years. Fortunately, fewer population centres were aff ected than in 1974 or 2010-11. All were strong La Niña years.
Further back, the largest southeast Queensland flood was recorded in February 1893. In fact there were two separate floods a fortnight apart, both well above anything recorded since at Brisbane. The first flood was driven largely by phenomenal rainfall north of Brisbane. Crohamhurst, in the Glasshouse Mountains, had 907mm on 3 February (still an Australian daily record), 1417mm in two days and 1964mm in four. It is likely that, had there been measurements at more elevated high-rainfall sites such as Maleny and Mt. Glorious, the totals there would have been higher still. The second event was more widespread with much of the area east of Toowoomba receiving 300mm or more in the three days from 16-18 February. Many sites in the region received more than 1000mm for the month and Crohamhurst ended up with 2999mm, which was high enough on its own to rank as the fourth-highest annual total there.
The records show...
Overall rainfall was heavier in 1974 than in 2011. In 1974, eastern Australia received 682mm over the five months from January to May, compared with 559mm for the five months from September 2010 to January 2011. January 1974, the wettest month of either period, was exceptional for the extent and persistence of rain. While there was no individual standout event outside the Brisbane area, widespread rain fell almost every day, the statewide daily average in Queensland exceeded 10mm on 17 consecutive days and the heavy rains extended all the way to and beyond the Northern Territory border. Central Queensland catchments such as the Fitzroy and Condamine-Balonne escaped relatively lightly in 1974, but further west almost every major river had record or near-record floods. In 2010-11 flooding in western rivers, while significant, was not exceptional.
This is a reprint of an article from the BoM Climate and Water Update Newsletter - March 2011
Mallee: Output from Decision Support Tools
Rainfall Deciles
Deciles generated by 'Rainman', developed by QLD DEEDI
| Month 2011Mildura | Decile | Ouyen | Decile | Swan Hill | Decile | Birchip | Decile | |
|---|---|---|---|---|---|---|---|---|
| January | 129 | 10 | 131 | 10 | 135 | 10 | 181 | 10 |
| February | 183 | 10 | 98 | 10 | 46 | 9 | 41 | 9 |
| Annual | 312 | 10 | 229 | 10 | 181 | 10 | 222 | 10 |
PYCAL
PYCAL soil moisture is calculated using rainfall from 1st Dec to date and evaporation rates from a bare soil surface using the Ritchie model. It is possible in some locations that November rain and/or the inclusion of stubble cover could increase these values.
| Mildura | Ouyen | Swan Hill | Birchip | |
|---|---|---|---|---|
| Plant Available Water (mm) | 310 Sandy loam |
235 Sandy loam |
105 Sandy Loam |
160 Loam |
Cumulative rainfall up until end of February with potential season outcomes (Decile 1,5,9) compared to the long term median (average). Graph sourced from the Australian Bureau of Meteorology. http://www.bom.gov.au/watl/rainfall/ranges.shtml
Wimmera: Output from Decision Support Tools
Rainfall Deciles
Deciles generated by 'Rainman', developed by QLD DEEDI
| Month 2011 | Nhill | Decile | Warracknabeal | Decile | Longerenong | Decile | Edenhope | Decile |
|---|---|---|---|---|---|---|---|---|
| January | 107 | 10 | 165 | 10 | 160 | 10 | 110 | 10 |
| February | 25 | 7 | 57 | 9 | 69 | 10 | 66 | 10 |
| Annual | 132 | 10 | 222 | 10 | 229 | 10 | 176 | 10 |
PYCAL
PYCAL soil moisture is calculated using rainfall from 1st Dec to date and evaporation rates from a bare soil surface using the Ritchie model. It is possible in some locations that November rain and/or the inclusion of stubble cover could increase these values.
| Nhill | Warracknabeal | Longerenong | Edenhope | |
|---|---|---|---|---|
| Plant Available Water (mm) | 108 Clay loam |
175 Clay loam |
170 Light clay |
190 loam |
Cumulative rainfall up until end of February with potential season outcomes (Decile 1,5,9) compared to the long term median (average). Graph sourced from the Australian Bureau of Meteorology. http://www.bom.gov.au/watl/rainfall/ranges.shtml
North East: Output from Decision Support Tools
Rainfall Deciles
Deciles generated by 'Rainman', developed by QLD DEEDI
| Month 2011 | Boort | Decile | Rochester | Decile | Tungamah | Decile | Rutherglen | Decile |
|---|---|---|---|---|---|---|---|---|
| January | 203 | 10 | 112 | 10 | 59 | 9 | 72 | 9 |
| February | 102 | 10 | 125 | 10 | 156 | 10 | 250 | 10 |
| Annual | 305 | 10 | 237 | 10 | 215 | 10 | 322 | 10 |
PYCAL
PYCAL soil moisture is calculated using rainfall from 1st Dec to date and evaporation rates from a bare soil surface using the Ritchie model. It is possible in some locations that November rain and/or the inclusion of stubble cover could increase these values.
| Boort | Rochester | Tungamah | Rutherglen | |
|---|---|---|---|---|
| Plant Available Water (mm) | 230 Clay loam |
165 Clay loam |
155 Clay loam |
210 Clay loam |
Cumulative rainfall up until end of February with potential season outcomes (Decile 1,5,9) compared to the long term median (average). Graph sourced from the Australian Bureau of Meteorology. http://www.bom.gov.au/watl/rainfall/ranges.shtml
South West: Output from Decision Support Tools
Rainfall Deciles
Deciles generated by 'Rainman', developed by QLD DEEDI
| Month 2011 | Hamilton | Decile | Willaura | Decile | Lismore | Decile | Winchelsea | Decile |
|---|---|---|---|---|---|---|---|---|
| January | 124 | 10 | 126 | 10 | 146 | 10 | 140 | 10 |
| February | 41 | 8 | 45 | 8 | 58 | 8 | 34 | 7 |
| Annual | 165 | 10 | 171 | 10 | 204 | 10 | 174 | 10 |
PYCAL
PYCAL soil moisture is calculated using rainfall from 1st Dec to date and evaporation rates from a bare soil surface using the Ritchie model. It is possible in some locations that November rain and/or the inclusion of stubble cover could increase these values.
| Hamilton | Willaura | Lismore | Winchelsea | |
|---|---|---|---|---|
| Plant Available Water (mm) | 150 Clay loam |
180 Sandy clay loam |
115 Sandy loam |
90 Sandy clay loam |
Cumulative rainfall up until end of February with potential season outcomes (Decile 1,5,9) compared to the long term median (average). Graph sourced from the Australian Bureau of Meteorology. http://www.bom.gov.au/watl/rainfall/ranges.shtml
The Fiver
Floods on the web
After a bit of a break from churning out The Fiver (blame locusts and floods, not my inability to multitask) I feel all inspired to do a huge dump of websites. I am going to resist and drip feed over the coming months.
Hopefully you will see the quality, compelling themes and value add as you read through them. As part of the quality control for an enjoyable relevant Fiver, we are doing our annual Break survey where we ask you if we are making a difference and how you think we can improve the product. Please do the survey! The results are widely read and your input much appreciated.
So where do you get quality flood information on the web? Well it depends a bit. I quite like NEARMAP for great crisp images of how high the flood rose in many areas throughout Australia. If you head to the Horsham page and focus in on Quantong, you can see my house and land. We were far luckier than many around the state. Mind you if you work for government you won’t be able to access the site while at work.
http://www.nearmap.com
DSE have made a number of images of the floods available. There are cool before/after flickr shots and the aerial imagery from around Kerang-Swan Hill. The flood severity map I think is great for the display of the January floods. Hopefully a February one is also created.
http://www.water.vic.gov.au/__data/assets/pdf_file/0018/107208/DSE-flood-severity.pdf
http://www.dse.vic.gov.au/
http://www.flickr.com/photos/dsevictoria/sets/72157625892582168/
Next up is the flood data itself. The tools everyone was using to let the Indian drums beat on how high the floods would get. The first link is the obvious flood warning page at the BOM.
http://www.bom.gov.au/australia/warnings/index.shtml
Once the flood watch appears then it is onto rainfall watching. I find this the go-to table when wanting to get snapshots of how wet it has been
http://www.bom.gov.au/vic/observations/vicall.shtml
To check the rainfall for the last 24 hours to 9am and for the last week, I use this link and scroll to the middle of the page to get the daily and weekly rainfall bulletins.
http://www.bom.gov.au/vic/observations/index.shtml
Once the rain has bucketed down it’s off to the rainfall and river height site. Choose the river height display and then click on the station I am interested in.
http://www.bom.gov.au/vic/flood/
I then choose to look at the river height bulletin for the particular area of interest.
http://www.bom.gov.au/vic/flood/rain_river.shtml
Finally I choose the rainfall and river data to get the historical rainfall and river height data so I can then can become a “qualified hydrologist who knows floods.” (I know this statement is not true).
http://www.bom.gov.au/water/about/agencyDataAuxNav.shtml
To use it you need to find the river height station you are most interested in, then you become data rich looking at the historical data and flood heights from past floods.
Finally I promised some sexy pictures that would say you read The Break for the pictures not the stories.
http://blog.reflexstock.com/2009/07/23-awesome-photos-not-photoshops/
By Chris Sounness (DPI, Horsham)
Editors:
DPI Horsham:
De-Anne Price & Chris Sounness
03 53622111
deanne.price@dpi.vic.gov.au
chris.sounness@dpi.vic.gov.au
DPI Cobram:
Dale Grey
03 58710600
dale.grey@dpi.vic.gov.au
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Published by the Department of Primary Industries, Grains
110 Natimuk Rd
Horsham Vic 3401, September 2010
