Eastern Australia Sees another Coastal Low

Elsewhere in Weather News posts are beginning to sound like a broken record with all the recent flooding stories coming out of Australia. This past week there were yet again significant flash flooding problems across regions of Australia.

[map zoom=”11″ type=”hybrid” autofit=”1″ disable_scrollwheel=”1″] [pin tooltip=”Last week’s flooding”]Maitland, AU[/pin] [pin tooltip=”This week’s flooding”]Lismore river[/pin] [/map]

Northern New South Wales and southern Queensland were hardest hit this time as a low pressure quickly wrapped up just off the Eastern Coast of Australia – very similar to the setup that occurred last week. Observation sites indicate that there was a large swath of 150-200mm that fell across Northern NSW along the coast in just over 24 hours. With already saturated soils from the past week’s storm that dumped around 50mm in the same area, conditions were primed for flash flooding once the heavier rain bands arrived. Similar to last week’s low featured in EIWN, strong wind gusts of up to 100km/h were also observed.

Surface Map analysis from overnight Thursday shows the east coast low just off Australia's eastern shores and the tropical storm Quang about to make landfall on Western Australia territory. (Source: BoM)
Surface Map analysis from overnight Thursday shows the east coast low just off Australia’s eastern shores and the tropical storm Quang about to make landfall on Western Australia territory. (Source: BoM)

Flash flooding was the main cause of the damage in the region once again, as roads washed out and numerous homes were inundated. The Wilson and Lismore rivers were expected to peak later today at a moderate flood stage, meaning that properties along the banks of the rivers are at risk. In total, six people died from the most recent flood events, five of the six as they attempted to drive through flood waters that covered roads. This brings a harsh reminder to residents that when roads get flooded out it’s best to turn around and not drive through.

The east coast low wasn’t the only form of severe weather to affect Australia this past week – a cyclone also formed in the Eastern Indian Ocean and strengthened in to a category four over open waters. After substantially weakening due to cooler waters near Australia’s coast the system made landfall on Northwestern Australia’s shores as a tropical storm, prompting officials to issue rainfall warnings in the region. Damage from the storm appears to have been minimal, other than some minor flooding.

Elsewhere in Weather News: March 8th, 2014

Cyclone Takes Aim at Northern Queensland

On Thursday, March 7th an area of convection appeared off the northern coast of Australia in the Arafura Sea, associated with a weak tropical disturbance. Since then the convection has remained nearly stationary due to steering winds being fairly weak but not much organization has occurred. However, the disturbed area is expected to organize quickly today into tomorrow as it drifts slightly to the southeast where shear values are low and sea surface temperatures are very warm; 30-31°C. By Sunday evening it is expected that Gillian become a category two cyclone, just off the northern coast of Queensland.

Infrared satellite image of Gillian looking rather disorganized, but with some deep convection on Friday evening. (Source: CIMSS)
Infrared satellite image of Gillian looking rather disorganized, but with some deep convection on Friday evening. (Source: CIMSS)

The Australian Bureau of Meteorology (BoM) warns that winds could approach 150km/h in areas closest to where it makes landfall. Shoreline areas are most at risk along the peninsula due to the storm surge and large waves. Flooding/flash flooding is also expected as areas along the coast have received around 850mm in February; over double their average rainfall for that month. Another 250-400mm could fall in the region due to Gillian. It is expected that Gillian linger through the beginning of next week and die out as it continues south over land.

Queensland's rainfall for the past 30 days, note the area of 800+mm, this is where Gillian is headed. (Source:BoM)
Queensland’s rainfall for the past 30 days, note the area of 800+mm, this is where Gillian is headed. (Source:BoM)

Interestingly enough a second, weaker, cyclone is spinning off the east coast of Queensland and is expected to make landfall at about the same time that Gillian does as a strong category one. Both cyclones are to watch Sunday into the beginning of next week as they pose a threat to the northern and eastern areas of Queensland. The Australian cyclone season begins November 1st and ends April 30th and on average they see about ten cyclones per year.