Rainfall update 20 September 2018
Rainfall for the month to date
Rainfall so far in September has been below average.
Seasonal rainfall
Rainfall since 1 April has been good in some parts, however southern parts of the grainbelt are still tracking at decile 2-3 rainfall. Monthly rain to date [2] is available from the DPIRD weather stations and radar page (select Month to Date from the drop-down menu).
Soil mositure
Soil mositure map shows relative root zone soil water storage to 19 September 2018 from the Bureau of Meteorology’s Landscape Water Balance model [4]. Good rain in August has improved soil water storage for much of the grainbelt and the south coast. Parts of the south-eastern grainbelt remain with relatively low levels of soil water storage for this time of year.
For soil water estimates at individual locations with and without crop water use refer to the Soil water tool [5].
Potential yield
Potential crop yield is estimated using the French-Schultz equation, and uses seasonal rainfall from 1 April to date. Rainfall for the rest of the growing season (to 31 October) is assumed to be decile 5. This model does not account for crop diseases or soil constraints. There is little change in yield potential from the previous report, as most of the seasonal rainfall is unchanged.
Rainfall forecast for the next two weeks
There is little rainfall forecast for the next two weeks.
Rainfall forecast [8] for the next week shows only light rain expected for the south coast.
Beyond next week, the US NCEP [10] model indicates only light rainfall for the second week. All climate models surveyed indicate September to November is more likely to be drier than normal. This appears to raise the risk of a drier than normal finish to the 2018 growing season.