Objective: The National Farmer's Federation in Australia requested a seasonal forecast for the spring season (September to November) based on the latest forecast (early August 2016). Rural activity in Australia is affected significantly by the El-Nino Southern Oscilation (ENSO) and/or the Indian Ocean Dipole (IOD), the two key drivers of Australia's climate. To learn more about IOD the Bureau of Meteorology (BoM) produced a schematic illustration of the IOD and its impact on Australia's weather.








Mockup image file mockup_IOD_2.png (version 4) not found. Did someone delete it?



The BoM makes available to the public updates of the Indian Ocean Dipole Index (see below). The index is the difference of area average SSTs between two regions in the Indian Ocean. Identify what is the current (July 2016) phase of IOD.

Skill of the forecast

Now that the sources of predictability are identified, lets learn about the forecast skill of the seasonal forecast system. A comprehensive assessment of Seasonal Forecast System 4 is available in a technical memoranda http://www.ecmwf.int/en/elibrary/11209-new-ecmwf-seasonal-forecast-system-system-4 .

Additionally,  the forecast skill of weather parameters is available as well with the seasonal forecast products on the web http://www.ecmwf.int/ (then select Forecasts →Charts → Long Range → Spatial Maps) .

Select the Ensemble-mean correlation for 2m temperature for valid for June-July-August and compare with the same map but for precipitation (map below).


What can you say about the skill of the forecast system for both temperature and precipitation (in particular for Australia) ?


Forecast Products

Climagrams are a subset of the seasonal forecast products currently available on the web. Find the corresponding Climagram for the sea surface temperature area average corresponding to the IOD index (discuss within the group what information is displayed in the chart). Compare it with the previous forecast started on July.  What can you say about the consistency between consecutive forecasts (July & August) for the target months (Sep. to Nov.) ?


Check as well the "Spatial Maps" products. In particular the "Ensembe Mean" and "tercile summary" (probabilistic) maps for temperature and precipitation. What the Farmers Federation can expect for the coming Spring (Sep-Oct-Nov 2016) ?

Verification (To be shown later ...)