543 replies to this topic

[HurricaneJosh]

am19psu, on 21 December 2011 - 06:47 AM, said:

I'm pretty ok with comparisons to Tracy at this point. That's pretty much the type of storm I'm forecasting (if it stays offshore)

Ooooohhhh, don't stop!

[Sunny and Warm]

Anybody have a SST map for the region down under?

[am19psu]

Sunny and Warm, on 21 December 2011 - 09:34 AM, said:

Anybody have a SST map for the region down under?

http://www.weatherzo...r_sst.jsp?c=sst

[HurricaneJosh]

The BoM has initiated advices on 94S. The long-term forecast-- not pictured here-- has it drifting WSW and strengthening to near Cat 3 (60 kt (10-min)) by 72 hrs. The Technical Bulletin indicates that the longer-term motion could be either WSW or ESE. As is often the case in this basin, the steering currents are not well-defined:

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[am19psu]

HurricaneJosh, on 21 December 2011 - 10:51 AM, said:

The BoM has initiated advices on 94S. The long-term forecast-- not pictured here-- has it drifting WSW and strengthening to near Cat 3 (60 kt (10-min)) by 72 hrs. The Technical Bulletin indicates that the longer-term motion could be either WSW or ESE. As is often the case in this basin, the steering currents are not well-defined:

The 3-5 day track forecast is the big wildcard. The stupid Arafura Sea is so difficult to forecast for track. If it stays over water, this thing is going to blow up over the weekend. It wouldn't shock me if this storm was sitting at 100 kts (1-min) Monday morning, if it is still over water.

[HurricaneJosh]

am19psu, on 21 December 2011 - 10:59 AM, said:

The 3-5 day track forecast is the big wildcard. The stupid Arafura Sea is so difficult to forecast for track. If it stays over water, this thing is going to blow up over the weekend. It wouldn't shock me if this storm was sitting at 100 kts (1-min) Monday morning, if it is still over water.

Wow.

And long-term, what general area of the coast do you feel is most threatened-- or can you even say at this point?

[am19psu]

HurricaneJosh, on 21 December 2011 - 11:05 AM, said:

Wow.

And long-term, what general area of the coast do you feel is most threatened-- or can you even say at this point?

Nope. The model tracks look like a squished spider.

[HurricaneJosh]

am19psu, on 21 December 2011 - 11:07 AM, said:

Nope. The model tracks look like a squished spider.

lolz

[HurricaneJosh]

For reference, here's the track of Cyclone Tracy (1974). It's interesting how it carefully skirted around the Tiwi Islands and then rolled into Darwin with perfect aim-- like a bullet. The track was so diabolical it was almost as if it was "on purpose".

As I mentioned above, the BoM recently reanalyzed it, and they estimate the landfall intensity at Darwin to be 95 kt (10-min)-- a very strong Cat 3 on our scale:

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[Sunny and Warm]

am19psu, on 21 December 2011 - 09:46 AM, said:

http://www.weatherzo...r_sst.jsp?c=sst

Thanks.

WOW. It certainly won't lack for energy. Is shear and/or winds coming off Oz an issue in a manner similar to South America for storms close to that continent?

[am19psu]

Sunny and Warm, on 21 December 2011 - 11:26 AM, said:

Thanks.

WOW. It certainly won't lack for energy. Is shear and/or winds coming off Oz an issue in a manner similar to South America for storms close to that continent?

No, not really. This basin is similar to the NIO in spring/fall with the way the monsoon trough is situated wrt land.

[OzTCchaser]

Gidday folks,
Some very interesting reading regarding the thoughts on the NT development. Down here in Darwin we have been spending many days trying to make sense of the model madness and attempting to resolve to a solution, and I suppose the balance from our point of view tends to lean towards the W/SW solution in the medium term before the inevitable SWT induced recurvature. I tend to think that given the more westerly initiation point that the GFS scenario seems a little unreasonable. The idea of an inland trough capturing this system from such a position just doesn't seem to compete with what looks to be a reasonable STR to the west cradling it and gradually moving it W/SW given the likelyhood of what looks like becoming a rapidly intensifying midget TC in the next 36 hours.

Anyway, I would be very interested to hear more of the views of our American friends in regards to this development. We are currently posting our thoughts and current chase plans at http://www.xweatherl...75&p=5417#p5417 and on our FB page http://www.facebook....zcyclonechasers . Also for anyone interested, we will be live streaming our attempts to intercept this system (pending internet coverage in what could be some remote areas) via Severe Studios on our website www.ozcyclonechasers.com

Look forward to the input from the clearly very knowledgeable crew at Americanweather ( brilliant forum by the way )

Cheers

[Sunny and Warm]

am19psu, on 21 December 2011 - 11:30 AM, said:

No, not really. This basin is similar to the NIO in spring/fall with the way the monsoon trough is situated wrt land.

Thanks. This is my first foray into Aussie TC's, so I'm sure I'll come up with some dumb questions as I read the thread.

[Sunny and Warm]

OzTCchaser, on 21 December 2011 - 11:42 AM, said:

Gidday folks,
Some very interesting reading regarding the thoughts on the NT development. Down here in Darwin we have been spending many days trying to make sense of the model madness and attempting to resolve to a solution, and I suppose the balance from our point of view tends to lean towards the W/SW solution in the medium term before the inevitable SWT induced recurvature. I tend to think that given the more westerly initiation point that the GFS scenario seems a little unreasonable. The idea of an inland trough capturing this system from such a position just doesn't seem to compete with what looks to be a reasonable STR to the west cradling it and gradually moving it W/SW given the likelyhood of what looks like becoming a rapidly intensifying midget TC in the next 36 hours.

Anyway, I would be very interested to hear more of the views of our American friends in regards to this development. We are currently posting our thoughts and current chase plans at http://www.xweatherl...75&p=5417#p5417 and on our FB page http://www.facebook....zcyclonechasers . Also for anyone interested, we will be live streaming our attempts to intercept this system (pending internet coverage in what could be some remote areas) via Severe Studios on our website www.ozcyclonechasers.com

Look forward to the input from the clearly very knowledgeable crew at Americanweather ( brilliant forum by the way )

Cheers

welcome!

[am19psu]

New Euro absolutely crushes Darwin with a Tracy repeat at 0z on the 28th.

[HurricaneJosh]

am19psu, on 21 December 2011 - 01:38 PM, said:

New Euro absolutely crushes Darwin with a Tracy repeat at 0z on the 28th.

Wow.

[HurricaneJosh]

Re: Darwin and cyclones...

Although the city is deep in the tropics and is of course famous for being flattened by Cyclone Tracy, it's not terribly cyclone-prone. Part of it has to do with geography: it's really "tucked in" to the Top End, and a cyclone has to approach from a very particular angle to score a direct hit.

Since Tracy, no hurricane-strength cyclones have directly hit the city. And before then, the only big events were in 1897, 1917, and 1937. The details Re: these events is sketchy, but apparently each had a great impact on the city. The 1897 cyclone in particular was a monster.

[am19psu]

HurricaneJosh, on 21 December 2011 - 01:56 PM, said:

Re: Darwin and cyclones...

Although the city is deep in the tropics and is of course famous for being flattened by Cyclone Tracy, it's not terribly cyclone-prone. Part of it has to do with geography: it's really "tucked in" to the Top End, and a cyclone has to approach from a very particular angle to score a direct hit.

And to Josh's point, the 12z Euro really is the perfect scenario for a devastating hit to Darwin. The storm recurves southeastward and bombs out just prior to landfall.

Take all of this with a grain of salt, since it is a 156hr model forecast. If it stays over water, though, it has a very high chance of bombing out to an intense cyclone and the Euro has been showing this SE recurve scenario for a few runs now.

[Ed Lizard]

Looks like about $1500 from Prague to Sydney.


Just saying.

[calamity]

12z ECMWF saved for verification purposes.



The GFS, on the other hand, shoots the cyclone east into the Coral Sea, so there's a lot of uncertainty with this one. The models have been consistently developing it for the past week or so.

[HurricaneJosh]

Ed Lizard, on 21 December 2011 - 03:32 PM, said:

Looks like about $1500 from Prague to Sydney.

Just saying.

Ha ha ha, what a troublemaker you are. But of course the idea did creep into my mind tonight-- especially because my company is closed down all next week and I could slip away without being missed. But it would still be terribly naughty and piggish after all the NATL and EPAC chasing is did this year.

calamity, on 21 December 2011 - 03:49 PM, said:

12z ECMWF saved for verification purposes.

Whoa-- look at that. I'm glad you saved it. That's quite a provocative model scenario there.

[HurricaneJosh]

Well... The 00Z Euro ain't quite as sexy. It has the low hovering in the general vicinity of Darwin and the Tiwi Islands for a couple of days-- then moving E, brushing the Top End and spilling out into the Gulf of Carpentaria, where it strengthens a bit and then goes poof!

Blah.

Here's the latest BoM forecast:

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[am19psu]

As I was saying yesterday, the Arafura Sea sucks for track forecasting. I'm looking at the Euro Ensemble members and they are split from the Cape York to Broome as a possible location by Wednesday afternoon (EST).

[HurricaneJosh]

am19psu, on 22 December 2011 - 06:06 AM, said:

As I was saying yesterday, the Arafura Sea sucks for track forecasting. I'm looking at the Euro Ensemble members and they are split from the Cape York to Broome as a possible location by Wednesday afternoon (EST).

Cape York to Broome... lolz.

[am19psu]

HurricaneJosh, on 22 December 2011 - 06:23 AM, said:

Cape York to Broome... lolz.

lolz indeed. There is a definitely an eastward skew to the ensemble tracks. The median track still looks like 94S will head around the Tiwis to south of Darwin and that's what I stuck with this morning.

[HurricaneJosh]

am19psu, on 22 December 2011 - 06:46 AM, said:

lolz indeed. There is a definitely an eastward skew to the ensemble tracks. The median track still looks like 94S will head around the Tiwis to south of Darwin and that's what I stuck with this morning.

Very interesting. And what kind of intensity are you calling for the near-Darwin landfall?

[am19psu]

HurricaneJosh, on 22 December 2011 - 06:51 AM, said:

Very interesting. And what kind of intensity are you calling for the near-Darwin landfall?

I mean, if it stays over water, this is an obvious RI case. I went Cat 2 (S-S) in my forecast today, but it could be stronger. Or, if the more overland solutions verify, it won't get past a weak TS.

[HurricaneJosh]

am19psu, on 22 December 2011 - 06:53 AM, said:

I mean, if it stays over water, this is an obvious RI case. I went Cat 2 (S-S) in my forecast today, but it could be stronger. Or, if the more overland solutions verify, it won't get past a weak TS.

Wow-- so bottom line: look out if this stays over water.

If the cyclone misses S of Darwin, it shouldn't be too big a deal, as there's not much civilization S of the city. All I can really find is Dundee Beach.

[HurricaneJosh]

By the way, during all this talk of 94S, Tropical Cyclone Fina formed and fizzled in the Coral Sea.

I don't care about it, but just didn't want a cyclone to slip by undocumented in this here thread:

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[am19psu]

HurricaneJosh, on 22 December 2011 - 08:10 AM, said:

By the way, during all this talk of 94S, Tropical Cyclone Fina formed and fizzled in the Coral Sea.

I don't care about it, but just didn't want a cyclone to slip by undocumented in this here thread:

IDQ65001.gif

[HurricaneJosh]

Omg. Troll.

Even the crappy cyclones need to be documented in this here thread.

[HurricaneJosh]

The latest BoM advice has the low center quite a bit further W. While the models seem to be converging on a SE solution, the low doesn't have to get much further W to skirt around the Tiwi Islands. Either, the system ain't organizing too fast, and the Technical Bulletin says cyclone status remains a good 36-60 hr away.

The track is so uncertain that the entire Top End remains under a Cyclone Watch:

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[calamity]

Worth noting, Wunderground has added Australian radar sites to their website. I haven't seen these posted on here before, but they could be useful if the cyclone passes close to Darwin.

[HurricaneJosh]

calamity, on 22 December 2011 - 11:34 PM, said:

Worth noting, Wunderground has added Australian radar sites to their website. I haven't seen these posted on here before, but they could be useful if the cyclone passes close to Darwin.

Yeah, the Australian radar system is pretty good. And if you want to view the data in their "native" format, you can go here: http://www.bom.gov.a...alia/radar/?ftr

[HurricaneJosh]

The Low shifted direction and moved E last night, and now it's just kind of meandering N of the Top End, where it's expected to become (and remain) a weak cyclone for a few days. (Typically erratic, loopy track for this region.)

The Technical Bulletin indicates that the models are agreeing on E motion in the longer term. The Euro is on board with that-- showing the cyclone strengthening in the Gulf of Carpentaria around Day 5 and crossing the Cape York Peninsula (from the W) around Day 6 as a strong cyclone.

A Cyclone Warning is in effect for central portions of the Top End.

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