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Aussie (& S-Hemisphere) Cyclone Action 2012-2013


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Aussie Region Cyclones
Because the party never ends for the Tropical Dudes! And as our hemisphere slowly starts to peter out, it's time to start looking Down Under for tropical pleasures. cool.png Australia's tropical cyclone season starts in one month-- on 01 November! thumbsupsmileyanim.gif

As I did previous years, I'm starting this thread with a quick primer on cyclones in Oz-- a reference source for those of you who want to get a basic lay of the land. (This info is reproduced from the previous years' threads because it's still useful!)

Geography
Here are the basic land areas and water bodies:

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Land
A large portion of Australia's coastline is threatened by cyclones. Since this is the S Hemisphere, it's like going through the looking glass-- meaning the tropics are to the N and therefore Australia's cyclone country is the N coast. This is actually a tremendous stretch of coastline that spans three states/territories:

* Queensland (QLD) (on the E)
* Northern Territory (NT) (in the middle)
* Western Australia (WA) (on the W)

Most of Australia's population is concentrated in the major cities in the SE-- Brisbane, Sydney, Melbourne, etc.-- and therefore Australia's cyclone country (up N) is mostly very sparsely populated. This means that intense cyclones often make landfall-- particularly in Western Australia-- without causing much damage.

Water
Like Mexico-- and unlike the USA-- Australia is threatened by cyclones from two oceans: the South Pacific to the E and the Indian to the W.

These two oceans are divided into several smaller bodies of water-- most of which are shallow, warm, and game for big cyclones:

The South Pacific (to the E) includes:

 

* Coral Sea-- along the E coast of Queensland
* Gulf of Carpentaria-- between Queensland and the Northern Territory
* Arafura Sea-- to the N of the Northern Territory


The Indian Ocean (to the W) includes:

 

* Timor Sea-- between Indonesia & Australia
* Joseph Bonaparte Gulf-- between the Northern Territory & Western Australia


Warning System
Australia's Bureau of Meteorology (BoM) handles cyclone warnings via its offices in the capital cities of each state/territory:

* BoM Queensland (QLD): Brisbane
* BoM Northern Territory (NT): Darwin
* BoM Western Australia (WA): Perth

Each BoM office has jurisdiction over its own region (including the adjacent waters), and when a cyclone passes from one region to the next, the responsibility for issuing advices (advisories) passes from one office to the next. Here's the regional breakdown (note that Eastern = Queensland):

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The different territories and jurisdictions means there's no convenient "one-stop shop" (like our National Hurricane Center) for tracking Aussie cyclones. (Grrrrr. biggrin.png) However, the BoM simplified their Website information architecture a couple of years ago, so now there's at least one convenient URL from which you can access the different regional warnings: http://www.bom.gov.au/weather/cyclone/.

All of this aside, the USA's Joint Typhoon Warning Center (JTWC) also covers the Aussie region, and they're a good secondary info source, although-- as discussed in other threads-- the JTWC tends to go a bit high with intensity estimates.

Tracking
If you feel inclined, here's the BoM's handy cyclone tracking map for the waters around Western Australia and the Northern Territory: http://www.bom.gov.a...racking_map.pdf cool.png

Here's one for the entire N coast of the continent, including Queensland-- Australia's entire cyclone zone: http://www.bom.gov.a...let/plotmap.pdf

Cyclone Intensity
In public advices, the BoM indicates cyclone intensity by max gusts-- not sustained (1-min) wind like our NHC. (However, technical discussions will express a sustained wind-- but note that it's a 10-min wind, not a 1-min wind like ours. The conversion factor-- to change a 10-min wind to a 1-min wind-- is ~1.13 to 1.15, depending on who you ask.) Also, note that for public advices, the Aussies use km/hr-- not mph like we do.

Aussie Intensity Scale
The Aussies have their own cyclone intensity scale-- as follows:

Cat 1 = max gusts: <125 km/h (<68 kt) -- max sustained (10-min): 63-88 km/hr (34-47 kt)
Cat 2 = max gusts: 125-169 km/h (68-91 kt) -- max sustained (10-min): 89-117 km/hr (48-63 kt)
Cat 3 = max gusts: 170-224 km/h (92-121 kt) -- max sustained (10-min): 118-159 km/hr (64-85 kt)
Cat 4 = max gusts: 225-279 km/h (122-151 kt) -- max sustained (10-min): 160-199 km/hr (86-107 kt)
Cat 5 = max gusts: >279 km/h (>151 kt) -- max sustained (10-min): >199 km/hr (>107 kt)

Aussie Intensity Scale vs. American Intensity Scale
How does the Aussie scale (AUS) compare to our Saffir-Simpson scale (USA)? It has five levels, but otherwise it's quite different! Here's a side-by-side comparison with ours:

Cat 1 AUS = tropical storm USA
Cat 2 AUS = tropical storm thru low/midrange Cat 1 USA
Cat 3 AUS = high/midrange Cat 1 thru low-end Cat 3 USA
Cat 4 AUS = midrange Cat 3 thru low-end Cat 4 USA
Cat 5 AUS = midrange Cat 4+ USA

Anything Cat 3 AUS and above is described as a "Severe Tropical Cyclone"-- so, while it sounds dramatic, this label could be (and is) applied to what we would call a strong Cat 1 'cane in the USA. biggrin.png

Here's an excellent graphic from the BoM's FAQs which illustrates the relationship between the Aussie and American intensity scales:

post-19-0-60969100-1349148238_thumb.png
______

OK-- there's your handy reference source for tracking Aussie cyclones!

Madagascar Cyclones
As we've expanded the scope of this thread to also include cyclones in the SW Indian Ocean, here's some updated stats Re: cyclones hitting Madagascar:

I decided just to concentrate on cyclones hitting Madagascar since 2000, as this last decade has been a very active period for the island nation. For the period 2000-2012, Madagascar had:

* 14 hurricane landfalls
* 8 major-hurricane landfalls (see note)
* 1 Cat-5 landfall (see note)

The map below shows the landfall points of all the majors. The NE portion of the island seems to be a magnet for intense landfalls-- so the second map zooms in on that region. Majors can hit the W coast (like Fanele 2009), but it happens much less often. (Note: These stats assume Bingiza 2011 was a Cat 3 (which I'm not sure about) and Gafilo 2004 was a Cat 5 (which technically it wasn't as per the updated SS Wind Scale that now puts the lower limit of Cat 5 at 137 kt).)

Not mentioned in these stats is a very near miss by another Cat 5-- Hary 2002-- which passed just offshore of that same NE region.

The large port city of Toamasina (pop. ~180K)-- on the E/C coast-- has been very lucky over the last decade, with no direct hits from any hurricane-strength cyclones. And the only 'canes to even come within 20 mi of the city in the last 30 yrs are Honorinina 1986 (Cat 1) and Geralda 1994 (Cat 3)-- so they've just been waaaaay lucky.

Note: Data are from Meteo France (La Reunion)-- the official agency for this region. All wind references are 1-min, converted from the original 10-min using a factor of 1.136. All scale references are the USA (SS) scale.

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post-19-0-56989300-1349148260_thumb.png

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Good first post. I don't feel so bad Bendy Mod locked my thread two weeks ago, nowhere near as informative, although the Oz cyclone chasers had all kinds of good nostalgia material on Cyclone Yasi.

Maybe this will be the year i-Cyclone spends 14 hours on a plane for a chase...

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Good first post. I don't feel so bad Bendy Mod locked my thread two weeks ago, nowhere near as informative, although the Oz cyclone chasers had all kinds of good nostalgia material on Cyclone Yasi.

Maybe this will be the year i-Cyclone spends 14 hours on a plane for a chase...

Thank you-- I'm glad you like it. :) Please feel free to post Yasi nostalgia/porn if you'd like-- it will put us all in the mood. :D

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Oh, and for anyone who's interested, Ed is referring to the the Oz Cyclone Chasers, a chasing duo who are the most high-profile hurricane chasers in Oz these days:

Facebook: http://www.facebook....zcyclonechasers

Website: http://www.auscyclonechasers.com/

They're awesome dudes-- really good guys whom I chat with often. We promote each others' work, etc.

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Quiet start to the Oz season-- however, models are hinting at some action in the S Pacific, with the Euro showing a hurricane-strength cyclone threatening Fiji in about a week.

Meanwhile, in the middle of the S Indian Ocean, S of Diego Garcia-- i.e., the middle of nowhere-- Cyclone Claudia is drifting S with winds of 105 kt.

Whatevz.

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Quiet start to the Oz season-- however, models are hinting at some action in the S Pacific, with the Euro showing a hurricane-strength cyclone threatening Fiji in about a week.

Meanwhile, in the middle of the S Indian Ocean, S of Diego Garcia-- i.e., the middle of nowhere-- Cyclone Claudia is drifting S with winds of 105 kt.

Whatevz.

I've consumed taxpayer subsidized beer during the Reagan years in Diego Garcia. Just passing through.

Nice lagoon, nice Class Six store, not much else. Claudia is a nice looking storm

post-138-0-80238900-1355039659_thumb.jpg

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The Fiji threat reminds me of how much I really dislike using the Fiji Meteorological Service Website. It's pretty dreadful-- not to mention slooooooow: http://www.met.gov.fj/

The NHC (USA) and BoM (Australia) have the best and most usable cyclone sites. The rest-- including the JMA and Meteo France and the one for the N Indian Ocean-- are pretty bad.

The JTWC's format is actually very good. We can debate their forecasting skill, but the graphical system is simple and informative-- you get all of the info (historical track & intensity, forecast track & intensity, cone of uncertainty) from one glance-- and it's also easy to dig deeper for more (in the text products).

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Not sure yet. But it's a good first step. The MJO should be favorable through at least the New Year.

At least...2nd half of December and first of Jan look more Niñaish, with averaging -OLR anomalies around the Timor and Arafura seas, probably a little closer to normal in the Coral sea.

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The Euro's lookin' less interesting tonight. It shows a low near Fiji kind of forming and jetting NE in the next couple of days (the JTWC has a Cyclone Formation Alert for it), and then another more substantial (but still not terribly sexy) cyclone forming and moving between Fiji and Vanuatu next week. Zzzzz.

Meanwhile, out in the middle of nowhere, Claudia is slowly weakening as it drifts S.

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