Seasonal Climate Outlook

Summary

The Department of Agriculture and Food, Western Australia’s Statistical Seasonal Forecast (SSF) system is indicating a mixed rainfall outlook for February-April 2017. However rainfall events and major flooding from a tropical low on 9-10 February means that February-April rainfall will be above average regardless of any more rainfall for the Great Southern and Esperance region.

  • The SSF is indicating 30-40% chance of exceeding median rainfall for the northern wheatbelt and south-west corner, 60-80% chance of exceeding median rainfall in the Great Southern and 40-60% (neutral chance) elsewhere. Predictive skill based on January conditions is poor to good (50-75% consistent).
  • The Bureau of Meteorology’s current seasonal outlook indicates that SWWA and the southern wheat-belt have equal chances of a wetter or drier February-April 2017, with 45-55% chance of exceeding the median rainfall. For the individual month of February the chances have increased to 60-80% but are lower 25-40% for the month of March. Predictive skill is poor to good (45-75% consistent).
  • Temperature outlooks from the Bureau indicate a 45-55% (neutral) chance of above normal day-time maxima and above normal night-time minima across the region for the February-April period (poor to good skill, 50-75% consistent).
  • Rainfall in January was average to above average in northern, central and south eastern parts of the South-West Land Division, but average to below average in the southwest. For SWWA, maximum temperatures were average to above average in January, whilst minimum temperatures were below average to average.

Three month outlook for the south-west of Western Australia

Statistical Seasonal Forecasting (SSF)

DAFWA’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.

The SSF forecast for February-April 2017 is indicating 30-40% chance of exceeding median rainfall for the northern wheatbelt and south-west corner, 60-80% chance of exceeding median rainfall in the Great Southern and 40-60% (neutral chance) elsewhere. Predictive skill based on January conditions is poor to good (50-75% consistent). The most probable decile range map indicates decile 2-3 rainfall for February-April for the majority of the wheatbelt and south-west and decile 8-9 for the Great Southern and north and east of the Esperance shire.

SSF forecast of probability of exceeding median rainfall for February to April 2017. Indicating 30-40% chance of exceeding median rainfall for the northern wheatbelt and south-west corner, 60-80% chance of exceeding median rainfall in the Great Southern a
SSF forecast of probability of exceeding median rainfall for February-April 2017
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-April rainfall using data up to and including January