World Meteorological Organization Expert Team Meeting CAgM ET 2.2 Nairobi 21 to 24 October 2008 Weather and Ocean Services Policy Branch
Agrometeorological tools Short term forecasts out to 7 days ahead. Forecast rainfall using a probability matched ensemble mean. Frost potential using the Operational Consensus Forecast. Longer term forecasts out to 3 to 12 months ahead. Seasonal forecasts. POAMA and ACCESS.D:\Loxton_photo\test2.jpg Decision support tools.d:\loxton_photo\p1010094.jpg APSIMD:\Loxton_photo\P1010094.JPGD:\Loxton_photo\test2.jpg Yield Prophet Whopper Cropper Pycal Aussiegrass
Forecast rainfall using a probability matched ensemble mean Operational since August 2006 in Australia Easy to understand colour coded maps indicating likely amounts of rainfall by day and by 1-4 and 5-8 day totals.
How does it work? Rainfall for each grid box from each of say 8 local and international forecast models is averaged and stored. Australia wide set of rainfall amounts for all grid boxes for all models is ranked highest to lowest Average values taken out again and the highest 8 values are assigned to the highest average grid box and reassigned the central value of the top eight. Repeat the process for the second highest and so on for all grid boxes.
How good is it? Reliability Relative Operating Characteristic (ROC)
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What has been said: I have been using your rain forecast site since it's release and wish to compliment the Bureau staff. I work at an isolated gold mine in the NT and regularly refer to teh site when managing our sites logistics etc. I don't hesitate to refer people to teh site which is uncanningly accurate. Congadulations Great site. The visual rainfall maps are tereffic. I have recently begun using your "forecast rainfall" and "chance of rainfall" maps (selecting the Kimberley and Northern Interior regions of WA) as tools for planning road (4WD) trips out from Halls Creek WA to various Aboriginal commuities for work purposes. These communities are each a few hundred kilometres out along dirt roads which are subject to effects of rainfall making them impassable. I have found your maps give me much greater confidence in judging whether or not a trip can be undertaken on a particular day (within the next five days) The forecast rainfall maps are brilliant. We're in the construction business and they will be useful when it starts to rain here again. (do you have a "click and drag" facility where we can use the mouse to pull some of that rainfall down here from Queensland?)
Feasibility of its use in other regions Can be configured to any domain worldwide. Can be configured for any number of model inputs. Can be run on relatively inexpensive computer hardware. Supercomputing not required. Internet access required for data gathering and dissemination. Provides daily forecast rainfall amounts and confidence level of receiving that amount of rainfall.
Frost potential service Statistical and multi model approach (ensemble) called Operational Consensus forecasts (OCF). Location based, automatic weather station sites with hourly data only. Hourly data computed out to 48 hours Five levels Grey Green Orange Dark orange Red Minimum temp above +4 deg C +1 to +4 deg C -2 to +1 deg C -5 to -2 deg C Less than -5 deg C Number of hourly predictions within each level is available by mouse over. Trial service until end 2008.
How does it work? Combining local and overseas computer forecast models and producing a forecast out to 2 days at hourly intervals. Models include 4 local and 5 overseas models at varying resolution and time intervals that are Blended into an hourly forecast. Comparing these with observed temperatures on a station by station basis over the past 30 days. A minimum sample of 15 days is required to determine the temperature bias. Adjust the blended model and sort the hourly temperature forecasts into categories and produce colour coded maps and tables of location based data. Produce web output once a day at around 5 pm EST with forecasts for the next 2 days.
Frost potential maps and tables + http://www.bom.gov.au/jsp/watl/weather/frost.jsppresented by Vernon Carr, Australian Bureau of Meteorology
Some limitations of this method Watch out for elevated stations. The table provides the station elevations above mean sea level. They tend to show a high level of frost potential through the most part of the winter months. It is believed that some alpine resorts may have some interest with this service for snowmaking. Based on computer guidance (temperatures) only. No forecaster input. Forecast is for the weather station (square metre below the instrument screen). Local knowledge will have to do the rest. This is well understood by most farmers using the service.
How good are the figures? Average minimum temperature errors (RMS) Day 1 forecast (2008): For Tasmania Day 2 forecast(2008): For Tasmania As a guide, use plus or minus 2 degrees C
Seasonal 3 month outlooks Users experienced difficulty in understanding our seasonal rainfall outlooks traditionally in terms of % chance of exceeding the median rainfall. Survey of farmers and natural resource managers driving the service change.
Seasonal 3 month outlooks Changed to chance of at least xx mm of rainfall over the next 3 months Or 75% of exceeding xx mm of rainfall Plus tables of values for a number of locations
Seasonal 3 month outlooks % chance of at least xx amount % chance of receiving a given amount
Decision support tools Agricultural Production Systems simulator APSIM from APRSU Plant, soil and management modules Simulates growth of crops, pastures and trees Inputs: Climate, location and management License fees. May be reduced for National Agricultural Research Systems in developing countries.
Yield Prophet Wheat, canola, sorghum & barley - dryland & irrigated Real-time information during crop growth Inputs: paddock-specific soil, crop & climate information Outputs: impact of management decisions [crop type & variety, sowing time, fertilisers, irrigation] on yield & quality Online, subscriber-only service
Whopper Cropper Grain & cotton - district-level output Targeted at advisors to explore crop management strategies at start of season Database of pre-run APSIM simulations (10 districts in Vic) Inputs: soil conditions, sowing date, plant density, N application rates Outputs: yield, protein levels, WUE, days to flowering, leaf area index CD-ROM based
Potential Yield Calculator [PYCAL] Cereals, legumes, oilseeds Inputs: rainfall to date & other climate data Outputs: potential yield; stored soil water; WUE Calculates likelihood of receiving rainfall to achieve target yield Less input data required than Yield Prophet More general application CD-ROM based
AussieGRASS Grazing and pasture application, providing regional-level output Simulation model based - accounts for interactions between climate, soils, fires, grazing management Outputs: forecasts potential grass growth & cover; projected grazing pressure; risk of degradation; impact of management decisions Internet-based, password protected; broadly field calibrated across all mainland states
Longer term strategies Improved understanding of seasonal outlooks Improved understanding of our variable climate Adaptation to climate change some winners some losers Longer term forecasts using dynamic coupled oceanatmosphere models for example POAMA and the Bureau s new numerical prediction suite ACCESS. Improved understanding of uncertainty in our forecasts Improved understanding of climate change versus climate variability.
Acknowledgements I would like to thank the following for their assistance with this presentation: Professor Roger Stone Professor in Climatology and Water Resources Director Australian Centre for Sustainable Catchments University of Southern Queensland, Toowoomba, Australia Mr Colin Creighton Land and Water Australia, Managing Climate Variability Program Dr Elizabeth E Ebert Centre for Australian Weather and Climate Research, Australian Bureau of Meteorology Dr Andrew B Watkins National Climate Centre, Australian Bureau of Meteorology