Seasonal Climate Outlook

Summary

The Department of Primary Industries and Regional Development’s (DPIRD) Statistical Seasonal Forecast (SSF) system is indicating less than a 40% chance of exceeding median rainfall for July to September and July to October 2018.

  • The SSF is indicating less than a 40% chance of exceeding median rainfall for the grainbelt for July to September 2018. The most probable decile range is decile 2-3 for most of the grainbelt. Predictive skill based on June conditions is mostly poor to good (50- 70% consistent).
  • The Bureau of Meteorology has a near-neutral rainfall outlook for July to September (a 40-50% chance of exceeding median rainfall). Predictive skill is mostly moderate to good (55-75% consistent) over southern WA.
  • Temperature outlooks for July to September 2018, from the Bureau of Meterology indicate a 50-80% chance of above normal day-time maxima for the south west land division (SWLD). Skill is poor to moderate at 50-65% consistent. Minimum temperature outlooks indicate a 60-80% chance of above normal night-time minima for the SWLD, with skill poor to moderate at 45-65% consistent.
  • For July to October, the SSF is also indicating less than a 40% chance of exceeding median rainfall for most of the grainbelt. The most probable decile range is decile 2-3 for most of the grainbelt. Predictive skill is mostly poor to good, 50 to 75% consistent.
  • June rainfall was below average for the grainbelt. June maximum temperatures were average to above average and minimum temperatures generally 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 web page.

For July to September, the SSF is indicating less than a 40% chance of exceeding median rainfall for the grainbelt. The most probable decile range is decile 2-3 rainfall for most of the grainbelt. Predictive skill based on June conditions is poor to good (50-75% consistent).

SSF forecast of the probability of exceeding median rainfall for July to September 2018. Indicating a drier than normal outlook (less than a 40% chance) of receiving median rainfall for the grainbelt.
SSF forecast of the probability of exceeding median rainfall for July to September 2018.

Percent Consistent skill of the SSF at forecasting July to September rainfall using data up to and including June. Skill is 50 to 70 percent consistent.
Percent Consistent skill of the SSF at forecasting July to September rainfall using data up to and including June.

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