30,000 People Urged to Evacuate Cairns, Australia, Due to Storm Surge Threat

In a statement released at 9:11PM Australian Eastern Standard Time, the Australia Bureau of Meteorology reported that Severe Tropical Cyclone Ita was crossing the Queensland Coast near Cape Flattery, with wind gusts reaching 230 km/hr (142 MPH). This makes Ita a dangerous category-4 tropical cyclone.

Severe Tropical Cyclone Ita made landfall shortly after 9:00PM Australian Eastern Standard Time on Friday, April 11. As the system tracks to the southwest and then south, strong winds and destructive storm surge are forecast for cities like Cooktown and Cairns.

A destructive storm surge is expected near and to the south of the landfall location. Cities that will likely be impacted by the surge include Cooktown and Cairns. More than 30,000 people have been urged to evacuate the Cairns area because of storm surge threat. Link: http://www.abc.net.au/news/2014-04-11/cyclone-ita3a-cairns-residents-brace-for-storm-surge/5385256.

Cairns is susceptible to storm surge in this case because the city is located on a harbor that is open to the northeast. The strongest onshore winds from Ita will blow right into the harbor and help funnel high storm surge towards Cairns. Although harbors are typically safe place for marine infrastructure, during tropical cyclones, storm surge levels are typically higher inside harbors than other areas along the open coast.

The harbor at Cairns opens to the northeast, which will enable Ita's strongest winds in this area to funnel water onto the Cairns' waterfront. People along this coastline are at risk from storm surge inundation. Image: www.yesaustralia.com.

A radar loop provided by Brian McNoldy at the University of Miami shows Ita making landfall, and the progression of intense squalls moving south along the Queensland Coast. Link: http://andrew.rsmas.miami.edu/bmcnoldy/tropics/radar/. Surge levels from Cooktown to Cairns should continue to build as Ita tracks to the southwest, then south.

A still image from radar loop shows progression of intense squalls moving south along Queensland Coast. Radar loop provided by Brian McNoldy at: http://andrew.rsmas.miami.edu/bmcnoldy/tropics/radar/.