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#1468969 - 17/08/2018 08:56 Re: Giant High Pressure Systems [Re: Chris Stumer]
pete28 Offline
Weatherzone Addict

Registered: 08/01/2007
Posts: 1164
Loc: Christchurch, New Zealand
Originally Posted By: Chris Stumer
If this pattern persists into spring and summer, it's going to get very hot because the sinking air in the high pressure system will trigger compressional heating and add to that clear skies, it's going to make for brutal heatwaves.


If we look at the cycle of what's been happening overseas with exceptionally hot heatwaves then Australia could well be in for it's first 50C temp since 1998....

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#1468975 - 17/08/2018 11:35 Re: Giant High Pressure Systems [Re: Sillybanter]
Eigerwand Offline
Weather Freak

Registered: 28/05/2012
Posts: 526
Originally Posted By: Sillybanter
I probably won't add much to help you here but for me this winter is more about the strong frontal systems continually rolling across the southern ocean. This is highlighted by very wet conditions around the SW exposed parts of the country e.g. SE South Australia and SW Wester OZ. I suspect the SAM has a lot to do with this. In the past when we see blocking high pressure in the Souther Ocean and the Tasman Sea we get more cut off cold pools that drift NE out of the bight and trigger rain events over Eastern Australia. This year I have seen none of this activity to remember. Funny enough the set up over the next week 10 days looks like it may finally produce this type of situation, but time will tell if it really happens.
Originally Posted By: Eigerwand
“A stronger than average high pressure system over central and eastern Australia”. That was taken from the latest weatherpulse clip w.r.t. rainfall this winter.
My point in starting this thread was to bring to light something I saw as being unusual, which it did in fact turn out to be and hopefully get some input as to what might be going on to make this so. Sadly most of the replies have been “seen it all before” as the pattern in question fits in well with a certain theory so despised by the experts on here that to bother actually understand what was going on might raise a couple of uncomfortable questions.

That said I am still hopeful someone may jump in and offer some explanation behind the ‘stronger than avg STR of 2018’.


Yeah just two sides of the same coin for mind. It appears the stronger than usual
STR residing over the continent has kept the westerly belt of polar lows locked down south, preventing much divergence north and by way of that not allowing air from low latitudes to penetrate south.

This article relates to the surf but is relevant for the analysis given to SAM. It’s interesting to note the long range node has seemed to be stationed at such a point to give southern WA a hiding. Perhaps this may shift east before winters end and we may see a little more action in the east of the country at comparable latitudes.

http://www.swellnet.com/news/swellnet-an...east-coast-flat

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#1468987 - 17/08/2018 15:32 Re: Giant High Pressure Systems [Re: Eigerwand]
Sillybanter Offline
Weather Freak

Registered: 17/03/2017
Posts: 58
Loc: Toowoomba
I actually see it different. I think the westerly belt is higher than usual(further north as indicate by SAM) which is squeezing the high pressure belt into a long week belt of high pressure that sits east to west over Australia. IMO when the polar activity is to high, Australia is dominated by a westerly flow which brings dry and stable weather to 90% of the continent. When the polar activity retreats south we get larger highs that that are slightly further south and produce onshore winds onto the east coast. This moisture travels west across the continent before being picked up by frontal systems.
Originally Posted By: Eigerwand
Originally Posted By: Sillybanter
I probably won't add much to help you here but for me this winter is more about the strong frontal systems continually rolling across the southern ocean. This is highlighted by very wet conditions around the SW exposed parts of the country e.g. SE South Australia and SW Wester OZ. I suspect the SAM has a lot to do with this. In the past when we see blocking high pressure in the Souther Ocean and the Tasman Sea we get more cut off cold pools that drift NE out of the bight and trigger rain events over Eastern Australia. This year I have seen none of this activity to remember. Funny enough the set up over the next week 10 days looks like it may finally produce this type of situation, but time will tell if it really happens.
Originally Posted By: Eigerwand
“A stronger than average high pressure system over central and eastern Australia”. That was taken from the latest weatherpulse clip w.r.t. rainfall this winter.
My point in starting this thread was to bring to light something I saw as being unusual, which it did in fact turn out to be and hopefully get some input as to what might be going on to make this so. Sadly most of the replies have been “seen it all before” as the pattern in question fits in well with a certain theory so despised by the experts on here that to bother actually understand what was going on might raise a couple of uncomfortable questions.

That said I am still hopeful someone may jump in and offer some explanation behind the ‘stronger than avg STR of 2018’.


Yeah just two sides of the same coin for mind. It appears the stronger than usual
STR residing over the continent has kept the westerly belt of polar lows locked down south, preventing much divergence north and by way of that not allowing air from low latitudes to penetrate south.

This article relates to the surf but is relevant for the analysis given to SAM. It’s interesting to note the long range node has seemed to be stationed at such a point to give southern WA a hiding. Perhaps this may shift east before winters end and we may see a little more action in the east of the country at comparable latitudes.

http://www.swellnet.com/news/swellnet-an...east-coast-flat

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#1468990 - 17/08/2018 16:02 Re: Giant High Pressure Systems [Re: Eigerwand]
petethemoskeet Offline
Weatherzone Addict

Registered: 13/08/2003
Posts: 1392
Loc: toowoomba
Just reading about the Hadley cell and wondering how much influence this circulation is contributing to our current weather.

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#1469017 - 17/08/2018 21:29 Re: Giant High Pressure Systems [Re: Eigerwand]
Seina Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7770
Loc: Adelaide Hills
Originally Posted By: Eigerwand
Yes of course. It wasn’t like this over summer and lots of Eastern Aus has been in drought since then. But a dominant and stable STR has been more pronounced since about May this year compared with years past and has contributed to the worsening dry and also helps to explain other weather we have observed this winter over large parts of the country.

I agree with the above smile .


Edited by Seira (17/08/2018 21:38)

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#1469019 - 17/08/2018 21:51 Re: Giant High Pressure Systems [Re: Seina]
Seina Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7770
Loc: Adelaide Hills
Originally Posted By: Eigerwand
“A stronger than average high pressure system over central and eastern Australia”. That was taken from the latest weatherpulse clip w.r.t. rainfall this winter.

What is this weatherpulse clip -- is there a link smile ? I can't find one in this thread.

Originally Posted By: Eigerwand
My point in starting this thread was to bring to light something I saw as being unusual, which it did in fact turn out to be and hopefully get some input as to what might be going on to make this so. Sadly most of the replies have been “seen it all before” as the pattern in question fits in well with a certain theory so despised by the experts on here that to bother actually understand what was going on might raise a couple of uncomfortable questions.

A link to an abstract was provided within this thread, which I would understand is very relevant to the discussion smile . Here it is again:
http://onlinelibrary.wiley.com/doi/10.1029/2009GL037786/abstract

Originally Posted By: Eigerwand
That said I am still hopeful someone may jump in and offer some explanation behind the ‘stronger than avg STR of 2018’.


It can be described smile .


Edited by Seira (17/08/2018 21:53)

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#1469020 - 17/08/2018 21:56 Re: Giant High Pressure Systems [Re: Sillybanter]
Mega Offline
Meteorological Motor Mouth

Registered: 03/02/2003
Posts: 7899
Loc: Maryborough, Wide Bay, QLD
Originally Posted By: Sillybanter
I actually see it different. I think the westerly belt is higher than usual(further north as indicate by SAM) which is squeezing the high pressure belt into a long week belt of high pressure that sits east to west over Australia. IMO when the polar activity is to high, Australia is dominated by a westerly flow which brings dry and stable weather to 90% of the continent. When the polar activity retreats south we get larger highs that that are slightly further south and produce onshore winds onto the east coast. This moisture travels west across the continent before being picked up by frontal systems.


I see it the same way. Highs are further north and fronts are continually lashing WA/southern SA & VIC but they have no head because there's no moisture infeed from the IO. When SAM goes + the westerly wind belt retreats further south as do the highs...and finally we get some onshore flow and moisture from the Pacific ocean.

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#1469031 - 18/08/2018 09:16 Re: Giant High Pressure Systems [Re: Mega]
Sillybanter Offline
Weather Freak

Registered: 17/03/2017
Posts: 58
Loc: Toowoomba
Cheers Mega I forgot to mention the Indian Ocean which is equally important as a moisture source. Which missing in action this year by the way. Living in inland Australia for most of your life you tend to pay close attention to moisture sources because without moisture you have no chance of rain. And you came to realise how many influences have to come together to produce rain in these parts that its almost a fluke when it actually does. And its why we can still have dry conditions in a La Nina. Because its just a small part of the puzzle that has to come together.
Originally Posted By: Mega
Originally Posted By: Sillybanter
I actually see it different. I think the westerly belt is higher than usual(further north as indicate by SAM) which is squeezing the high pressure belt into a long week belt of high pressure that sits east to west over Australia. IMO when the polar activity is to high, Australia is dominated by a westerly flow which brings dry and stable weather to 90% of the continent. When the polar activity retreats south we get larger highs that that are slightly further south and produce onshore winds onto the east coast. This moisture travels west across the continent before being picked up by frontal systems.


I see it the same way. Highs are further north and fronts are continually lashing WA/southern SA & VIC but they have no head because there's no moisture infeed from the IO. When SAM goes + the westerly wind belt retreats further south as do the highs...and finally we get some onshore flow and moisture from the Pacific ocean.

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#1469034 - 18/08/2018 11:19 Re: Giant High Pressure Systems [Re: Eigerwand]
ozone doug Offline
Weatherzone Addict

Registered: 06/11/2006
Posts: 1928
Loc: Roma SW QLD Eye to the West...
+1 for sillybanter . For MY location 90% of my rain comes from the North West and probably 5%from the South and 5% from the east. So we rely whats happening on the weather from the far North West or North. Which is in the dry for a fair while now .
_________________________
Cheers Doug. 491 Doug/ uhf ch40 When severe weather
BOM Stormspotter G0388 Roma S W Queensland Formerly Redcliffe.

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#1497848 - 23/04/2019 20:59 Re: Giant High Pressure Systems [Re: Eigerwand]
Eigerwand Offline
Weather Freak

Registered: 28/05/2012
Posts: 526
By the looks of the latest MSLP charts this looks like it might be a thing again. I remember last year it kicked off in late May though.

It is of course my own anecdotal experience however over the course of 30years of looking at pressure charts the current ones, like the ones last winter (and we all remember the peculiar weather they produced) are something of an anomaly.

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#1497849 - 23/04/2019 21:16 Re: Giant High Pressure Systems [Re: Eigerwand]
Funkyseefunkydo Offline
Weather Freak

Registered: 30/04/2007
Posts: 906
Loc: East Lake Macquarie
I expect the same blocking highs with cut off lows in between and constant SW winds on nsw coast.

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#1498044 - 28/04/2019 19:50 Re: Giant High Pressure Systems [Re: Eigerwand]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 3184
Loc: Tweed Heads
crikey _eigerwand
The AAO has been mainly positive for many years.
2015 to now has been exceptional( looking at the time series data below.)
I am currently loosely testing a theory that positive AAO and large ballooning highs coincide.
I have noted that the speed of the high pressure belt is slower in a pos AAO and so gives rise to increased blocking events.
The blocking event of nov 2018 to March 2019 was all pos AAO
The high pressure cells balloon possibly because the 'drag' on air parcels is reduced with a slower flow
A slower high pressure belt gives rise also to less frequent troughing.

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/aao/month.aao.gif
_________________________
http://weathercycles.wordpress.com/

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#1502869 - 19/07/2019 16:37 Re: Giant High Pressure Systems [Re: Eigerwand]
Funkyseefunkydo Offline
Weather Freak

Registered: 30/04/2007
Posts: 906
Loc: East Lake Macquarie
These big arse highs ay! Hadley cell expansion is here!

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