Cyclone 19/20 Australian Monsoon & TC Season Thread

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POW Hungry

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BoM should issue their National TC outlook in the next 2-3 weeks.

However, there's a few murmurs coming in from our neighboring regions regarding the forthcoming 2019/20 Tropical Cyclone season.

I couldn't imagine much action out of the NW shelf for a few months given the dry atmos as a result of the record +IOD event.

Nonetheless, SST's are showing some + anoms in the NW, and not far off supportive TC development 26/27C.
Coral sea is currently under the influence of cooler waters (-'ve anom).
anomc.10.10.2019.gif


global_small.c.gif
 
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chunky

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From Weatherzone for this season :-

Here are the names that will be given to the next 11 tropical cyclones that develop in Australia's area of responsibility:

  • Blake
  • Claudia
  • Damien
  • Esther
  • Ferdinand
  • Gretel
  • Harold
  • Imogen
  • Joshua
  • Kimi
  • Lucas
Anyone can request to have their name added to Australia's tropical cyclone naming list. However, the request has to be submitted to the Bureau of Meteorology in writing and if it does get accepted, it'll take more than a decade before it's used.
 

StormyLee

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*Sorry I put this in the NW thread initially, so have copy and pasted into this one instead.

So we had our first little storm of the season in Karratha last week, approx 4 - 6 weeks early for us. Airport rain gauge only gave us 0.2mm but it would have been a touch more than that, it was running off of the roof anyway and had a good flow down the road. The plants were happy :thumbs:

BOM released their 19/20 cyclone season outlook two weeks ago, Western Region is looking at a similar season to last year according to them:
Summary of the Tropical Cyclone Seasonal Outlook for Western Australia:
- ~40% chance of an above average number of tropical cyclones in waters off the northwest coast (average number five).
- Likelihood of around two coastal impacts.
- Significant risk of at least one severe tropical cyclone coastal impact during the season.
http://www.bom.gov.au/cyclone/outlooks/seasonal/wa.shtml

Lots of discussion around this upcoming season seems to be focused around the current Positive IOD and a late onset for the monsoon, but the waters to our NW shoulder seem to not GAF. Take a look at the below SST anomalies for the past week, not really what you would expect to see is it. All that warm water just cooking away waiting to birth some pretty clouds, will the NW do it's own thang once again? I'm feeling it. I'm not buying into all the doom and gloom for us anyway, I reckon we're going to jag an alright wet season. Is it too early to call it as a wet cyclone season minus the cyclones? I'm thinking more tropical lows, thunderstorms etc.

SSTs.PNG
 

Michael Hauber

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Lots of discussion around this upcoming season seems to be focused around the current Positive IOD and a late onset for the monsoon, but the waters to our NW shoulder seem to not GAF. Take a look at the below SST anomalies for the past week, not really what you would expect to see is it. All that warm water just cooking away waiting to birth some pretty clouds, will the NW do it's own thang once again? I'm feeling it. I'm not buying into all the doom and gloom for us anyway, I reckon we're going to jag an alright wet season. Is it too early to call it as a wet cyclone season minus the cyclones? I'm thinking more tropical lows, thunderstorms etc.

I think the IOD has resulted in drier and hotter conditions over NW Australia. The result is that the hot land mass is locally pulling against the general SE trades associated with the IOD, resulting in doldrums and sunny conditions over water near the Australian NW coast, and so warming up SSTs. Further west the SE trades are blowing strongly and keeping things cool. These winds are also removing moisture from the general region. Perhaps once the IOD breaks down the hotter landmass will result in a more intense monsoon due to this heat. So late but intense. Also we are under El Nino modoki influence which also favours late and intense monsoon activity.

EC surface winds 8am 30/10 via windy:

IOD winds.PNG


Edit: BOM IOD impact page only shows impacts up to Oct-Dec, with rainfall impacts clearly reducing but still evident for this period. Interesting that rainfall is enhanced in NW, but sparse rainfall during that time of year may make the data unreliable. There is also the issue of el nino/+ve IOD often occurring at the same time so NE Qld impacts may be ENSO and not IOD.

rain-decile-1012-pos-iod-lr.png
 
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Flowin

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I often find with site https://ruc.noaa.gov/tracks/ that going back to previous time of forecast issue shows forecast that are not apparent fully for current time. This maybe due to upload delays. Anyway I think HWRF at least is still producing forecasts for Rita or SH 01 as at 25 November 06Z.
 
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_Yossarian_

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*Sorry I put this in the NW thread initially, so have copy and pasted into this one instead.

So we had our first little storm of the season in Karratha last week, approx 4 - 6 weeks early for us. Airport rain gauge only gave us 0.2mm but it would have been a touch more than that, it was running off of the roof anyway and had a good flow down the road. The plants were happy :thumbs:

BOM released their 19/20 cyclone season outlook two weeks ago, Western Region is looking at a similar season to last year according to them:
Summary of the Tropical Cyclone Seasonal Outlook for Western Australia:
- ~40% chance of an above average number of tropical cyclones in waters off the northwest coast (average number five).
- Likelihood of around two coastal impacts.
- Significant risk of at least one severe tropical cyclone coastal impact during the season.
http://www.bom.gov.au/cyclone/outlooks/seasonal/wa.shtml

Lots of discussion around this upcoming season seems to be focused around the current Positive IOD and a late onset for the monsoon, but the waters to our NW shoulder seem to not GAF. Take a look at the below SST anomalies for the past week, not really what you would expect to see is it. All that warm water just cooking away waiting to birth some pretty clouds, will the NW do it's own thang once again? I'm feeling it. I'm not buying into all the doom and gloom for us anyway, I reckon we're going to jag an alright wet season. Is it too early to call it as a wet cyclone season minus the cyclones? I'm thinking more tropical lows, thunderstorms etc.

SSTs.PNG
BoM seasonal outlook suggests average rainfall off the NW over summer.

rain.forecast.median.national.month1.20191121.hr.png

rain.forecast.median.national.season1.20191121.hr.png


SSTs of the NW still holding above average.
20191126.ssta_pacific_weekly.png
 

Jacko4650

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If and when things liven up there will be a few observers up here. Myself and @William here in Cairns and @whether down the road in Townsville. I'm pretty sure there are a few North Queensland refugees from Weatherzone in here as well.
Whilst direct hits from cyclones are less likely here on the Fraser Coast, trailing lows that cause flooding are more realistic and of significant concern. Last biggie was 2013 - another dry, hot start to summer I heard??
 
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_Yossarian_

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AshestoAshes

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Yeah Euro is sniffing out a bit of a disturbance in a similar area too. Dry mids might be an issue down the track, time will tell.

20191221_092754.jpg
Would this create the onset of the monsoon because the main run (EC) is backing a small low with the NW wind flow accompanying it. That would be bang on time as well if it was.
 
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comet

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The IOD atmospheric state is certainly starting to change, but I don’t think it will be fully done until midway in January.

This is good news I think?
Perhaps major floods for 2020 summer?
The unit above me flooded on 3-12-2019 and made a horrible, catastrophic mess on 4 floors.
I, and many others, had to out to temp. accommodation until the power and air con. could be restored.
I wondered, as I experienced the huge upheaval and stress of all of this, whether it may have been an harbinger of things to come?
Just some thoughts. Hope they are not inappropriate.
 

Orebound

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Jul 4, 2019
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Would this create the onset of the monsoon because the main run (EC) is backing a small low with the NW wind flow accompanying it. That would be bang on time as well if it was.

At this stage the cross-equatorial flow looks to be relatively weak and the convergence associated with an "active" phase of the monsoon looks confined to the Top End and points westward. Whether or not there is any incursion onto the Top End coast will depend on if and where any potential low pressure areas might develop. Generally speaking a focal point to the west of Darwin would minimize any significant monsoon incursion.

Climatology suggests the week between Christmas and New Year for the first active monsoon phase (usually over the NT coast and northern Cape York) so at best it will likely be a week or two late.
 

Michael Hauber

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Capture.PNG


EC forecast 850hp winds for Tuesday 31st at 6pm. NW Pacific is quite favourable with a nice easterly flow fed by a high in the NW Pacific - a good sign for a possible transition from el nino modoki conditions towards La Nina. At the same time the SW Pacific has a tropical system a long way east which is drawing a week westerly wind burst in the western Pacific and drawing away some of the moisture from the NW Pacific. This is also blocking any E or NE flow to the east of the monsoon activity which might otherwise give NE Australia more rain. Its promising to see an almost total absence of weak low pressure systems in the NW Pacific which have been frequently drawing away monsoon energy in the last couple seasons. In the Indian there is still a fair easterly flow, with enhanced convection near the east coast of Africa which is also drawing away some of the NW Pacific infeed. Finally there is a week southerly flow off the coast of WA which is feeding dry air into the general westerly flow to the north of Australia, so that the moisture isn't as good as it might otherwise look.

It seems that despite unfavorable patterns in Pacific and Indian Oceans that are still drawing monsoon moisture away from Australia, the strength of the flow with the NW, combined with the amount of warmth north of Australia, and in the heat low over land are managing to draw in some of this flow in the middle.
 

Greysrigging

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Accumulated precip numbers on the rise for those parts of the coast exposed to the convergent W-NW flow (via EC)

Capture.PNG


ecmwf_mslp_uv850_aus_11.png
Hope so..... I want some rain down Timber Creek way to fire up the Barramundi fishing in the Victoria River..... there is a Million Dollar Fish out there with my name on it....err... ok I'll settle for a 10k one.
 

Orebound

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Hope so..... I want some rain down Timber Creek way to fire up the Barramundi fishing in the Victoria River..... there is a Million Dollar Fish out there with my name on it....err... ok I'll settle for a 10k one.

I haven't made it down to the VRD as yet this season but I'm sure I'll be passing through there at some point in the next couple of months, I usually head over to the Pilbara a couple times each wet season. I can imagine however that the Vic is extremely low and in desperate need of a some big falls up in the catchment.

You better take the over the top GFS solutions then if you're going to have a chance of nailing that million dollar barra LOL

Capture.PNG
 

Orebound

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Euro operational still toying with the idea of developing a TC off the Kimberley coast in the later parts of its run, ensemble has been consistently entertaining the idea also with solutions varying between a track over land and well off to the west out at sea. Long way off so nothing more than interest value at this stage.

Capture.PNG
 
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