Seasonal Climate Outlook

Summary

The Department of Primary Industries and Regional Development’s (DPIRD) Statistical Seasonal Forecast (SSF) system is indicating below median rainfall for the majority of the South-West Land Division (which includes the wheatbelt) for August to October 2017.

  • The SSF is indicating less than a 30% chance of exceeding median rainfall for August to October for the majority of the wheatbelt. For southern areas of the northern agricultural area, a small area of the central wheatbelt and south coast, chances are higher at 40-60%. For the Metropolitan region and Dardanup shire chances are higher still at 60-80%. The most probable decile range map indicates decile 2-3 rainfall is most likely for the majority of the wheat-belt. Predictive skill based on July conditions is poor to good (50-75% consistent).
  • The Bureau of Meteorology’s current seasonal outlook indicates the South-West Land Division (SWLD) has a 30-40% chance of exceeding median rainfall for August to October. Predictive skill is poor to moderate (45-65% consistent).
  • In the shorter-term, weather forecasts are indicating good rainfall for the first half of August.
  • Temperature outlooks for August to October from the Bureau indicate a 70-80% chance of above normal day-time maxima for the SWLD. Skill is poor to good at 50-75% consistent. Minimum temperature outlooks indicate 65-75% chance of above normal night-time minima for the SWLD, with poor skill at 45% consistent.
  • July rainfall in the South-West Land Division was generally near average. Maximum and minimum temperatures were near average to above average.

Three month outlook for the south-west of Western Australia

Statistical Seasonal Forecasting (SSF)

DPIRD’s Statistical Seasonal Forecast (SSF) system uses historical relationships between global sea surface temperature and sea level pressure with rainfall in south-west Australia to produce forecasts of rainfall for the coming months. Users can click on any station indicated on the map for location-specific forecast information from the Seasonal Climate Information page.

The SSF forecast for August to October 2017 is indicating less than a 30% chance of exceeding median rainfall for August to October for the majority of the wheatbelt. For southern parts of the northern agricultural area, and a small area of the central wheatbelt and south coast, chances are higher at 40-60%. For the Metropolitan region and Dardanup shire chances are higher still at 60-80%. Predictive skill based on July conditions is poor to good (50-75% consistent).

SSF forecast of probability of exceeding median rainfall for August to October 2017 indicating 0-30% chance of exceeding median rainfall for the majority of the wheatbelt.

SSF forecast of probability of exceeding median rainfall for August to October 2017.

Percent Consistent skill of the SSF at forecasting August to October rainfall using data up to and including July. Skill is between 50 and 75 percent consistent

Percent Consistent skill of the SSF at forecasting August to October rainfall using data up to and including July.