Dry July just the beginning as El Nino takes hold
THE Coffs Coast is experiencing its driest winter in 20 years as the influence of El Nino takes hold.
Just 88mm of rain has fallen on Coffs Harbour this winter - the lowest since 1995 when 65mm was recorded, and significantly down on last year's three month average of 321mm.
Bureau of Meteorology climatologist Felicity Gamble said a significant El Nino event was causing below average rainfall across eastern Australia
"The El Nino in the Pacific Ocean is continuing to strengthen and that's having an effect across much of the eastern seaboard," Ms Gamble said
"Sea surface temperatures in the central and eastern tropical Pacific Ocean are becoming warmer than average, causing a shift in the atmospheric circulation.
"High-pressure systems are meanwhile tending to sit over Australia, making it harder for clouds to develop and bring rain."
While Coffs Harbour recorded record rainfall during autumn, just 55.8mm of rain fell in June, 32.2mm in July, and rain gauges have remained empty in August.
Ms Gamble said historic modelling of El Nino events suggested dry and warmer conditions were here to stay.
"Historically we've seen El Nino linked with severe drought, warmer daytime temperatures and bushfire activity," Ms Gamble said.
"We're also in unprecedented times as we've never had an El Nino event in the current climate of global warming.
"We've now seen the hottest six months on record, the Indian Ocean has recorded its hottest July on record and 2015 is on track to become the hottest year on record.
"On the positive side, widespread flooding and tropical cyclones tend to be less frequent during an El Nino."
The Bureau of Meteorology is also monitoring other factors including sea surface temperatures to the north of Australia and in the Indian Ocean which are also affecting current conditions.
The El Nino is forecasted to last until autumn when the influence of the positive Indian Ocean dipole is expected to kick in.
August 2015 rainfall - 0mm. Long term average - 80.2mm
July 2015 rainfall - 32.2mm. Long term average - 72.5mm
June 2015 rainfall - 55.8mm. Long term average - 120.8mm