543 replies to this topic

[HurricaneJosh]

boomer, on 17 November 2011 - 04:04 AM, said:

http://rammb.cira.co...tifier=SH952012
It's quite clear why I am unhappy with how the region is observed.
See above
Too late now... as to your comment re me feeling more comfortable elsewhere... don't you think that is rather snide?
If you put up a forum, you take all comers, no matter how they may rock the established cosiness.
If you do not wish it to be a genuinely public forum then place restrictions on who can enter (or you can just make it so unwelcoming they will feel they have to go elsewhere).
Or then again, they may feel like staying.

You have got to be the biggest bore on the planet. No one cares. Move on from it.

[am19psu]

So, it's looking like the MJO will swing around near Dec 1. Monsoon trough setting up by the 3rd? First storm by the 7th?

[alby_14]

am19psu, on 21 November 2011 - 05:37 PM, said:

So, it's looking like the MJO will swing around near Dec 1. Monsoon trough setting up by the 3rd? First storm by the 7th?

Could be on the mark there! Below is from the Weekly Tropical Note, which is updated every Tuesday and can be found here: http://reg.bom.gov.a.../tropnote.shtml





Weekly Tropical Climate Note
Issued on Tuesday 22 November 2011


La Niña conditions continue in the Pacific
La Niña conditions remain in place over the Pacific Ocean. Forecast models surveyed by the Bureau suggest the event is likely to peak towards the end of 2011, and persist into early 2012. It is considered unlikely that the current La Niña will be as strong as La Niña event of 2010-11.

Below average sea surface temperatures (SSTs) and sub-surface temperatures persist across the tropical Pacific Ocean. The latest weekly data from the NINO3.4 region shows SSTs are below average, at −0.8 °C. Cloudiness near the International Date Line continues to be below average.

The Southern Oscillation Index (SOI) has dropped slightly compared to last week, with a 30-day SOI value of +8.3 to the 19th of November. The contributing pressure anomalies are +0.9 hPa at Tahiti and −0.3 hPa at Darwin. The monthly SOI for October was +7.3. The 5-month running mean (centered on August) was +6.4.

La Niña periods are usually associated with above average rainfall across northern Australia during the wet season. Daytime temperatures are typically cooler from December onwards, and we tend to see more cyclone activity than normal between November and April.

See the Bureau's ENSO Wrap-Up which includes a compilation of ENSO computer model predictions.


The MJO heads into the Indian Ocean
Over the past couple of weeks, a fast moving Madden-Julian Oscillation (MJO) event has circumnavigated earth in just 30 days. A weak MJO is currently over Africa, heading east into the Indian Ocean. The majority of climate models surveyed by the Bureau of Meteorology suggest that if this MJO continues at the current speed, it will redevelop in the western Maritime Continent in early December.

Over the next week, decreased rainfall and tropical cyclone potential is likely in the northwest Pacific and the Maritime Continent, influenced by the current position of the MJO. However, an increase in cyclone potential is likely over the next week in the southwestern Indian Ocean.

Climatologically, the onset of the monsoon rains coincides with the Christmas holidays. Based on the current scenario, there is potential for an earlier onset of the monsoon across northern Australia.

See the Bureau's MJO Monitoring for more information, including rainfall maps.

Next update expected by 29 November 2011 | Product Code IDCKGEWOOO

For more information please contact climate.nt@bom.gov.au

[k***]

decent microwave presentation

[Ed Lizard]

Quote

IDW10800
Australian Government Bureau of Meteorology
Western Australia

Tropical Cyclone three-day outlook for the Western Region
Issued at 2:18pm WST on Monday the 5th of December 2011
Valid until midnight WST Thursday


Existing Cyclones in the Western region:
Nil.

Potential Cyclones:
At midday WST Monday, a tropical low was located near 12.2S 87.9E. The low is
expected to develop into a tropical cyclone to the west of 90E during Monday.
The system is expected to remain west of 90E on Tuesday but is likely to move
into the Western region as a cyclone during Wednesday.

Likelihood of this system being a tropical cyclone in the Western Region:
Tuesday :Low [out of area]
Wednesday :High
Thursday :High

Euro kills it long before it reaches W.A. But glass half full, the season is really starting,

[HurricaneJosh]

Hey, guys-- I'm back! Sorry for neglecting this thread. I was in Florida for a storm chasers' gathering, and then visiting my grandmother for a couple of days-- had my hands full.

So what's the bottom line? We have two cyclones way W of Australia, and they're both going to fizzle out there?

[Ed Lizard]

The NCEP page allows one to look at the GFS everywhere in the world. Except the Southern Hemisphere Indian Ocean, unless I am really missing something.

Attached Files

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[k***]

Ed Lizard, on 6 December 2011 - 12:56 PM, said:

The NCEP page allows one to look at the GFS everywhere in the world. Except the Southern Hemisphere Indian Ocean, unless I am really missing something.

Here is the eastern IO...the west is covered by all sorts of australian sites.
http://www.weatheron...&ZOOM=0&PERIOD= and

[Ed Lizard]

k***, on 7 December 2011 - 10:10 AM, said:

Here is the eastern IO...the west is covered by all sorts of australian sites.
http://www.weatheron...&ZOOM=0&PERIOD= and

Thanks. Bookmarked.

[k***]

still working on that SW eyewall

[HurricaneJosh]

boomer, on 12 December 2011 - 05:10 AM, said:

Willis Island Radar station (450km east of Cairns) is back up and running after being smashed by Yasi earlier this year. Staff had been evacuated the day before, but the radar dome got demolished and hence the radar.
It will soon be manned again meaning balloons will also be back.

Awesome news!

I was reorganizing my hard drive this weekend, including all my hurricane imagery. The radar shots of Yasi-- both from Willis Island and the radar-- are terrific additions to my collection.

Speaking of radar... The value of radar for post-analysis cannot be overstated. When a hurricane makes landfall without radar coverage, we're at a serious disadvantage afterward as we try to understand what happened and how strong it was. Hurricane Jova's landfall in a remote part of Mexico's Pacific coast in October is a good example of this. I believe it was a bit stronger than the operational estimate, but the radar site was down, and it's hard to really know what happened with the inner core without that. Grrrrr.

[HurricaneJosh]

Back on topic... The BoM outlooks for all three Aussie regions are totally negative for the next three days. We're in a lull.

[am19psu]

HurricaneJosh, on 12 December 2011 - 05:38 AM, said:

Back on topic... The BoM outlooks for all three Aussie regions are totally negative for the next three days. We're in a lull.

But, on the bright side, the monsoon trough looks to be building south over the next week or so, which should mean the first threat will be following up closely behind

[HurricaneJosh]

am19psu, on 12 December 2011 - 06:32 AM, said:

But, on the bright side, the monsoon trough looks to be building south over the next week or so, which should mean the first threat will be following up closely behind

Cool. I could use a good cyclone. Looking at all the Yasi imagery over the weekend kinda re-ignited my hawts for this basin.

[am19psu]

boomer, on 13 December 2011 - 07:44 AM, said:

Cmon guys.... take a stab... you are the experts

The monsoon trough is slowly sagging farther south and models aren't showing anything developing... until that happens, this thread will be mostly dead.

[EastCoastLow]

Remember what the monsoon trough did to potential TC's last year....totally sucked the life out of them. As soon as they'd look like forming, the trough would assimilate them.

[am19psu]

EastCoastLow, on 15 December 2011 - 03:11 AM, said:

Remember what the monsoon trough did to potential TC's last year....totally sucked the life out of them. As soon as they'd look like forming, the trough would assimilate them.

Huh? Explain.

[HurricaneJosh]

Still dead as a door nail-- but the Northern Region and Coral Sea outlooks are both mentioning a monsoon trough developing during the coming week. Hopefully it will bring a bit of fertility to these barren waters.

[HurricaneJosh]

By the way, Christmas is the 37th anniversary of Cyclone Tracy-- probably the most significant cyclone event in Australian history.

There's an ongoing debate about its intensity, which remains a rather contentious topic. A few years ago, the BoM's foremost Tracy expert and a thought leader in wind-pressure relationships, Joe Courtney, performed a close reanalysis of the cyclone's landfall at Darwin, and his verdict was 95 kt (10-min), which converts to ~110 kt (1-min)-- what we would call a high-end Cat 3 in the USA. As has been discussed here in the past, the cyclone was extremely small, with an RMW probably under 5 n mi-- a true microcane-- however, the inner core aimed perfectly and really smashed the city. The airport measured a peak gust of 117 kt (before the instrument failed) and 950 mb in the eye.

I'll do a more extensive post about Tracy around Christmas, if there's nothing else to talk about.

[HurricaneJosh]

The Euro has been hinting at a small, intense cyclone forming near the Kimberley coast and threatening the region around Christmas-- but I notice the latest (Mon 00Z) run seems to lose it.

Either way, it looks like we're about to enter a more fertile period. Cool.

[am19psu]

92P will probably get named, but it won't be more than monsoon depression-type piece of garbage.

The system in the Arafura Sea will be the one to watch later this week. Can't wait to spend Christmas morning forecasting

[HurricaneJosh]

am19psu, on 19 December 2011 - 07:26 AM, said:

92P will probably get named, but it won't be more than monsoon depression-type piece of garbage.

The system in the Arafura Sea will be the one to watch later this week. Can't wait to spend Christmas morning forecasting

Awesome-- we'll spend Xmas together-- you forecastin' and me peckin'.

[HurricaneJosh]

So things are getting more active.

* A Tropical Low (92P) has formed in the Coral Sea, SE of Papua New Guinea. It's expected to develop-- however, it should stay way offshore and not affect Queensland.

* More interesting is the Euro's repeated insistence on a small, very intense cyclone forming near the Top End and threatening the Kimberley in about a week (94S). The Northern Territory outlook is now suggesting a high likelihood of cyclone formation by Friday.

 Wind3285032and32mslp_Australia_192.gif   57.73K   0 downloads

[am19psu]

HurricaneJosh, on 20 December 2011 - 03:59 AM, said:

* A Tropical Low has formed in the Coral Sea, SE of Papua New Guinea. It's expected to develop-- however, it should stay way offshore and not affect Queensland.

Still boring.

HurricaneJosh, on 20 December 2011 - 03:59 AM, said:

* More interesting is the Euro's repeated insistence on a small, very intense cyclone forming near the Top End and threatening the Kimberley in about a week. The Northern Territory outlook is now suggesting a high likelihood of cyclone formation by Friday.

Yep. The big forecast dilemma is when/where does it move over land. The overnight Euro run was the first in the last 3 to keep it off land enough to intensify strongly.

[HurricaneJosh]

am19psu, on 20 December 2011 - 06:09 AM, said:

Still boring.

Totally. I felt obligated to mention it because it's on the map, but zzzzzz.

am19psu, on 20 December 2011 - 06:09 AM, said:

Yep. The big forecast dilemma is when/where does it move over land. The overnight Euro run was the first in the last 3 to keep it off land enough to intensify strongly.

Ah, OK. So that's why yesterday's runs looked so crappy? I hadn't looked that closely.

[HurricaneJosh]

The current Euro run brings the cyclone ashore in a remote areas with just wilderness and national parks. However, if it shifts a little further down the coast, some sizable towns (Broome (pop. ~14K) and Derby (pop. ~3K)) could be threatened.

[phil882]

HurricaneJosh, on 20 December 2011 - 06:16 AM, said:

The current Euro run brings the cyclone ashore in a remote areas with just wilderness and national parks. However, if it shifts a little further down the coast, some sizable towns (Broome (pop. ~14K) and Derby (pop. ~3K)) could be threatened.

It seems like the initial disturbance is currently just offshore on the N coast of the Northern Territory. The ECWMF shows a slow ramp up over the next 72 hours with more robust intensification beyond this period as it continues to drift westward.



Some Model Eye Candy

[HurricaneJosh]

The Euro is still showing it. The latest run depicts a small, intense cyclone forming very near Darwin and impacting the coast not too far away. The size/strength of the cyclone and the SE recurve kind of give this a Tracy vibe. (I know, very weenie thing to say.)

[tmagan]

Following the Joint Typhoon Warning Center web site reminds me of a pet peeve about their site: Their graphics are pretty much the same since the late 1990's.

[am19psu]

tmagan, on 21 December 2011 - 02:50 AM, said:

Following the Joint Typhoon Warning Center web site reminds me of a pet peeve about their site: Their graphics are pretty much the same since the late 1990's.

And they are terrible at forecasting tropical cyclones.

[HurricaneJosh]

am19psu, on 21 December 2011 - 06:07 AM, said:

And they are terrible at forecasting tropical cyclones.

Harshyharsh.

[am19psu]

HurricaneJosh, on 21 December 2011 - 06:11 AM, said:

Harshyharsh.

Welcome to 2011-12 Australia Season. This is what I do for 4 months out of the year.

[HurricaneJosh]

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

Welcome to 2011-12 Australia Season. This is what I do for 4 months out of the year.

Are you proud for me-- Re: my valuable donations to the science of analyzing unraveling tropical storms in MX?

[am19psu]

HurricaneJosh, on 21 December 2011 - 06:30 AM, said:

Are you proud for me-- Re: my valuable donations to the science of analyzing unraveling tropical storms in MX?

Don't sell yourself short. You also have valuable donations to the science of understanding unraveling tropical storms in the US, too!

[am19psu]

HurricaneJosh, on 21 December 2011 - 02:19 AM, said:

The Euro is still showing it. The latest run depicts a small, intense cyclone forming very near Darwin and impacting the coast not too far away. The size/strength of the cyclone and the SE recurve kind of give this a Tracy vibe. (I know, very weenie thing to say.)

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)