Three tropical cyclones have taken shape over the waters surrounding Australia.
Tropical Cyclone Pam developed early in the week to the east of the Solomon Islands and northwest of Fiji. Rapid strengthening throughout the week has brought Pam to exceptional strength, the equivalent of a Category 4 Hurricane in the Atlantic or Eastern Pacific.
While no direct landfall is expected as it continues its track southward to just north of New Zealand, there will be effects for the Islands to the north.
Tropical Cyclone Nathan slowly tracked westward throughout the week but now will take an abrupt u-turn and head back towards open water through the weekend. Before completely pulling away from the Cape York Peninsula, northern Queensland will get a few rounds of wet weather.
Flooding downpours are expected from just south of Cairns northward through Cape Melville where rainfall of 50-100 mm (2-4 inches) will be common with localized amounts over 200 mm (8 inches). While the strongest winds will remain offshore, isolated gusts can still result in downed branches and power lines into Friday.
The final area of concern takes us to the western coast of Australia where a cluster of showers and thunderstorms several hundred miles west of Broome developed into Tropical Cyclone Olwyn Wednesday evening, local time.
Olwyn continues to track southward, bringing with it the threat for strong winds and heavy rainfall.
Nicholls said “landfall on Friday, local time, is expected near Exmouth”. Olywn will then it will continue to slide along the Western Australia coastline. Rain is expected to extend southward to Perth throughout the weekend.
Flooding would likely be the greatest concern with this system, as rainfall amounts of 25-75 mm (1-3 inches) will be common. Any damaging winds will be limited to coastal areas near Exmouth, as weakening is expected once the potential cyclone interacts with the coastline. However, these coastal winds could be as high as 140 kph (85 mph) near landfall.
While the rain will potentially lead to flooding problems, the rains will also be beneficial in the long run around Perth and the surrounding area. Rainfall since Feb. 4 has totaled only around 1 mm (0.04 of an inch).
Southeastern parts of Australia continue to escape the rain and wind from these three tropical systems. However, a dazzling lightning show light up the sky in Sydney on Wednesday evening. This storm brought with it gusting winds that caused structural damage and power outages.
http://www.accuweather.com/en/weather-news/tropics-come-to-life-around-au/43664486