Forecast

Issue Notes

The hemispheric long wave pattern has been relatively fast moving in recent weeks. There are five main troughs. Currently the most significant troughs are near the longitudes of South Africa, the Indian Ocean, Western Australia, the south Pacific, and South America.

Summary:

Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 26 January to 30 January, 6 February to 10 February, and 15 February to 19 February. Rain events originating in the tropics and moving south are possible about 29 January to 2 February, 6 February to 10 February, and 21 February to 25 February. Over Western Australia the strongest cold fronts should occur about 12 February to 16 February, and 20 February to 24 February.

Issue Notes - Issued Jan 14

ENSO status: Neutral IOD status: Neutral SAM status: Trending neutral Sea surface temperatures (SSTs) across the equatorial central Pacific remained stable throughout December with the Nino3.4 index registering a value of 0.4 throughout the month. On the other hand, the Southern Oscillation Index (SOI) recorded a value of -5.5 in December. The current outlook suggests warmer than average SSTs will persist across the equatorial Pacific Ocean through the coming months, but remaining within neutral values. Six out of eight international models maintain a warmer than average equatorial Pacific Ocean through the first two quarters of 2020, none of these reaching El Nino thresholds. To the west of Australia, the Indian Ocean Dipole (IOD) has now returned to neutral, as waters off Western Australia have warmed up considerably. All six international models maintain neutral values until the austral winter with indications we could see another positive event later this year. In terms of rainfall across Australia, the current outlook favours a clearer below average rainfall signal for Western Australia and the Northern Territory through the remainder of January. This however, excludes any extreme weather events such as tropical cyclones. For the eastern states, there is a wetter than average signal for the coming weeks. Looking further ahead, with no significant signature from ENSO, there are no significant climate drivers tilting the balance towards a drier or wetter February. The current outlook suggests average-to-below average odds for February and March across the eastern states. The northern and western half of the country, however, could see a wet end to summer/start to autumn.