Australia braces for Cyclone Yasi as it hits Category 5

Simon at Australian Climate Madness notes this for rebuttal of the inevitable “Yasi caused by global warming” links that will be pushed on the blogs and by the press:

Tropical cyclone Mahina hit on 4 March 1899. It was a Category 5 cyclone, the most powerful of the tropical cyclone severity categories. In addition, Mahina was perhaps one of the most intense cyclones ever observed in the Southern Hemisphere and almost certainly the most intense cyclone ever observed off the East Coast of Australia in living memory. Mahina was named by Government Meteorologist for Queensland Clement Wragge, a pioneer of naming such storms.

Here’s what BoM has to say on their tracking page:

The forecast path shown above is the Bureau’s best estimate of the cyclone’s future movement and intensity. There is always some uncertainty associated with tropical cyclone forecasting and the grey zone indicates the range of likely tracks of the cyclone centre.

Due to the uncertainty in the future movement, the indicated winds will almost certainly extend to regions outside the rings on this map. The extent of the warning and watch zones reflects this.

This product is designed for land-based communities; mariners should read the coastal waters and high seas warnings.

Remarks:

SEVERE TC YASI IS A LARGE AND VERY POWERFUL TROPICAL CYCLONE AND POSES AN EXTREMELY SERIOUS THREAT TO LIFE AND PROPERTY WITHIN THE WARNING AREA, ESPECIALLY BETWEEN CAIRNS AND TOWNSVILLE.

THIS IMPACT IS LIKELY TO BE MORE LIFE THREATENING THAN ANY EXPERIENCED DURING RECENT GENERATIONS.

TC Yasi, CATEGORY 5, will continue to move in a west-southwesterly direction during the day. The cyclone is expected to cross the coast in the Innisfail area at about midnight.

Coastal residents within the warning area, and particularly between Cairns and Ayr are specifically warned of an EXTREMELY DANGEROUS SEA LEVEL RISE [i.e. storm tide] as the cyclone approaches, crosses the coast and moves inland. The sea is likely to steadily rise up to a level which will be VERY DANGEROUSLY above the normal tide, with EXTREMELY DAMAGING WAVES, STRONG CURRENTS and FLOODING of low-lying areas extending some way inland. People living in areas likely to be affected by this flooding should take measures to protect their property as much as possible, and be prepared to follow instructions regarding evacuation of the area if advised to do so by authorities.

DAMAGING WINDS with gusts to 90 km/hr that are currently developing on coastal islands, are forecast to develop about the coast by late morning and about the tropical interior overnight.

Between Cape Tribulation and Ingham these winds will become DESTRUCTIVE with gusts in excess of 125km/hr during the afternoon and early evening and VERY DESTRUCTIVE with gusts up to 300 km/hr between Cairns and Ingham during the evening as the cyclone approaches and crosses the coast. These VERY DESTRUCTIVE winds can also occur on the seaward side of hills to the north of the cyclone and are also forecast to reach the Atherton Tablelands.

Winds are forecast to ease about the east coast during Thursday morning as the cyclone moves inland.

FLOODING RAINS will develop from Cooktown to Sarina during the afternoon and then extend inland overnight.

People between Cape Melville and Sarina, extending inland to Croydon and Richmond should complete preparations quickly and be prepared to shelter in a safe place.

– Boats and outside property should be secured.

– For cyclone preparedness and safety advice, visit Queensland’s Disaster Management Services website (www.disaster.qld.gov.au)

– For emergency assistance call the Queensland State Emergency Service (SES) on 132 500 (for assistance with storm damage, rising flood water, fallen trees on buildings or roof damage).

People about the remaining tropical interior east of Camooweal and north of Winton should consider what action they will need to take if the cyclone threat increases.

– Information is available from your local government

– For cyclone preparedness and safety advice, visit Queensland’s Disaster Management Services website (www.disaster.qld.gov.au)

– For emergency assistance call the Queensland State Emergency Service (SES) on 132 500 (for assistance with storm damage, rising flood water, fallen trees on buildings or roof damage).

Name: Severe Tropical Cyclone Yasi

The next Forecast Track Map will be issued by 11:00 am EST Wednesday

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UPDATE:

Commenter sHx writes:

AS of this moment Yasi is right on top of Willis Island. http://en.wikipedia.org/wiki/Willis_Island

Apparently the island has a meteorological post. It even has radar! http://www.bom.gov.au/products/IDR412.loop.shtml

It must be frightening to be that radar operator looking at this, knowing when that eyewall hits you are going to be subject to Cat5 winds and you have a 30meter tall radar tower right next to you, and there’s really no shelter elsewhere on the island and no place to go. I wonder how long we’ll continue to get a signal from the Willis Island’s radar?

UPDATE2: Just about the time I pressed “update” the radar went out, the radar station is offline. The last image from the station is above. We hope for the best for the BoM employees there. The storm surge must be ferocious. Hopefully BoM evacuated them and they left the radar on “auto”. Given the size and composition of the island versus the size of the hurricane, Willis Island may very well be erased by this storm.

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Good luck to our friends in Queensland, especially Dr. Bob Carter and Nigel, who helped during my tour in Townsville last year.

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UPDATE 3: Hurricane expert Dr. Ryan Maue brings to our attention the differences in tropical cyclone scales. The Saffir-Simpson scale used maximum sustained one-minute winds while the Australian Region scale uses ten-minute averaged sustained winds.  The convention to convert is (10-minute)*1.14 = 1-minute sustained (units are knots).  This image combined from Wikipedia’s article.

The JTWC advisory intensity at 00Z Feb 2 of 125 knots is a strong Category 4 on the Saffir-Simpson scale.  The Australian Bureau of Meteorology reports central pressure of 930 hPa, and backs out Category 5 winds from that.  Also, feel free to call Yasi a “willy-willy“.