After having one of the driest starts to the wet season on record, the monsoon trough is making a comeback and is set to bring heavy rain and possibly a cyclone.
Since the end of January when Ex-Tropical Cyclone Oswald battered the east coast, northern Australia has seen a decrease in monsoonal activity thanks to the Madden Julian Oscillation having left the region.
The Madden Julian Oscillation is an eastward moving pulse of cloudy and rainy weather that affects the Australian region around every 30 to 60 days during the monsoon season. The oscillation is now becoming re-established in the Australian region, causing rain and thunderstorms to increase and elevating the risk of tropical cyclones.
So far this wet season parts tropical Australia have been particularly dry, with many northern parts of the NT recording 100-200mm less than normal between November and January.
Darwin Airport has recorded four months of below average rainfall. A total of 502mm fell between November and January, over 300mm less than normal. The Arnhem District has also been particularly dry. Nhulunbuy only received 162mm in the same period, more than 350mm less than usual, with no rain recorded at all during November. Meanwhile in WA's Kimberley, Broome only saw 58 percent of their regular rain between November and January.
As the monsoon ramps up this week, heavy showers and thunderstorms are likely across much of the northern tropics. A tropical low is also expected to form over the eastern Indian Ocean over the coming days. This low has a risk of developing into a tropical cyclone over the weekend and may affect WA's northwest coast early next week.
As the Madden Julian Oscillation tracks further east over the next week or two, it will heighten the risk of cyclone develop in the Coral Sea.
© Weatherzone 2013
20:25 EDT A dwindling number of volunteers is collecting some of the weather bureau's most important data from across South Australia.