Models predict drier than normal autumn ahead, says bureau

Soil moisture levels have fallen dramatically since September in many parts of the Central-West, the Hunter and areas of the Northern Tablelands.

The soil moisture concern comes as the Bureau says NSW is set to record one of its top five hottest summers on record. It also says a very weak La Nina event is about to end, to be replaced by a neutral period through winter where there will not be markedly wetter or drier conditions.

It says the driest areas emerging will be in western NSW, with some of the dry moving into the east.

Meanwhile, some of the state is facing some of the lowest soil moisture levels on record.

Dr Amgad Elmahdi, head of the BOM’s Water Resources Section, said a region of eastern NSW stretching from the Manning district to the north down to the Illawarra is now among the driest in Australia, compared with normal conditions.

“This dry condition has caused soil moisture to be below average across much of the state and very much below average around Scone and Hunter and Hawkesbury river, " Dr Elmahdi said.

 “In NSW over 2017 soil moisture has steadily declined over the majority of NSW over 2017 as the soil was pretty dry by the end of last year, following low monthly rainfall totals over 2017 (Feb, Jun, July in particular).”

The BOM’s manager of long-range forecasts, Andrew Watkins, said a weak La Nina event was ending “possibly within a couple of weeks”, that would lead to  a neutral weather period through much of autumn and winter.

“It has already been pretty dry in NSW especially in the northern areas. The south has benefitted from some good December rain and recently around Canberra. But we have had quite a dry January and February. We’ve had warmer than average days.” There has been high evaporation and a lot of run off on the harder soils.

“In autumn we are looking at drier than normal conditions, especially in western parts of the state including near Griffith and Broken Hill. Further east there is a 50 per cent outlook for drier or wetter condtions, that means it won’t be extremely dry or extremely wet. On the Southern Tablelands it may be about 60 per cent drier than average and that rises to about 65 per cent further west.”  It was  “very unusual’ to see such a weak La Nina event (normally bringing wetter conditions).

Meanwhile, Jamie Brown reports patchy rain has delivered welcome respite for dryland cotton growers in parts of the north-west, around Moree and the Gwydir catchment, east of the Newell Highway, with falls from 100 plus mm to 40mm, says Cotton Australia regional manager - Northern NSW Paul Sloman.

However early-planted dryland cotton in these areas has already ceased growing and the late rain will offer no benefit. 

West of the Newell, around Burren Junction rain failed to fall and water for irrigation has run out leaving growers short with yield expectations down around seven to 10 bales per hectare.