Seasonal Climate Outlook

Summary

The Department of Primary Industries and Regional Development’s (DPIRD) Statistical Seasonal Forecast system is indicating a neutral (40-60%) chance of exceeding median rainfall for February to April 2018 for the majority of the grainbelt.

  • The SSF is indicating a 40-60% chance of exceeding median rainfall for the majority of the South West Land Division (SWLD) for February to April 2018. This chance has increased to greater than 60% for the Lake Grace, Kondinin, Kulin and Esperance shires. There is a 30-40% chance for some parts of the central agricultural region. The most probable decile range map indicates decile 2-3 rainfall is most likely for the central grainbelt, with decile 8-10 rainfall for the southern grainbelt and Esperance and decile 4-7 elsewhere. Predictive skill based on January conditions is poor to good (50-70% consistent).
  • The Bureau of Meteorology’s current seasonal outlook indicates generally a 50-60% chance of exceeding median rainfall for February to April 2018 for the SWLD. Predictive skill is poor to moderate (45-65% consistent).
  • Temperature outlooks for February to April 2018 from the Bureau indicate a 30-55% chance of above normal day-time maxima for the SWLD. Skill is moderate to good at 55-75% consistent. Minimum temperature outlooks indicate a 35-55% chance of above normal night-time minima for the SWLD, with poor to good skill at 50-75% consistent.
  • January rainfall in the SWLD was above average due to ex-tropical cyclone Joyce bringing rainfall in mid-January. January maximum and minimum temperatures were near 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 is indicating a 40-60% chance of exceeding median rainfall for the majority of the SWLD. This chance has increased to greater than 60% for the Lake Grace, Kondinin, Kulin and Esperance shires. There is a 30-40% chance for some parts of the central agricultural region. The most probable decile range map indicates decile 2-3 rainfall is most likely for the central grainbelt, with decile 8-10 rainfall for the southern grainbelt and Esperance and decile 4-7 elsewhere. Predictive skill based on January conditions is poor to good (50-70% consistent).

SSF forecast of probability of exceeding median rainfall for February to April 2018. Indicating less mostly neutral outlook 40-60% chance of receiving median rainfall for the majority of the grainbelt and higher chances (above 60%) for part of southern ag
SSF forecast of probability of exceeding median rainfall for February to April 2018

Percent Consistent skill of the SSF at forecasting February to April rainfall using data up to and including January. Skill is 50-75 per cent consistent which is poor to good.
Percent Consistent skill of the SSF at forecasting February to April rainfall using data up to and including January