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#1208689 - 31/08/2013 10:10 Deep Southern Ocean Low
Nerd65 Offline
Weather Freak

Registered: 30/01/2011
Posts: 446
Loc: Cranbrook, Townsville
I notice on the latest MSL analysis chart (30/8 1800UTC) that there's a low analysed at 936hpa at approximately 52S 118E. That seems abnormally deep. I can remember seeing pressures down there in the 940-950hpa range but 936hpa seems exceptional.
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#1208732 - 31/08/2013 18:12 Re: Deep Southern Ocean Low [Re: Nerd65]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 3184
Loc: Tweed Heads
Hey.. THanks for the observation Nerd 65. Could you supply the source for the 936 hPa observations.
This the one l have used and l have trouble reading the MSLP values

http://www.bom.gov.au/australia/charts/indian_ocean.shtml
Do you have a better one?

MSLP values for JULY 2013 show low pressure anomalies in the southern ocean and high pressure over the OZ mainland. Contributing to our warm winter mainland anomalies

The August out in a few weeks Anomlay should be VERY interesting
------------

JULY 2013 MSLP ANOMALY

http://www.bom.gov.au/cgi-bin/climate/cm...d=month&area=sh


--------------------------------


I have updated a report on the stratosphere and whats been going on around the southern oceans and Antartica that goes along way to explaining the current MSLP pattern
linked here
http://forum.weatherzone.com.au/ubbthrea...min#Post1208730


Edited by crikey (31/08/2013 18:15)
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#1208740 - 31/08/2013 19:07 Re: Deep Southern Ocean Low [Re: Nerd65]
Mad Elf #1.5 Offline
Weatherzone Addict

Registered: 05/03/2012
Posts: 3856
Loc: Mt Hallen QLD
Hey Nerd 65, 936hpa is comp to a cat 5 cyclone. Deep stuff & hope someone can confirm.
If it gets near Tas or NZ at that intensity, people will be in for a hell of a ride!
Crikey could be onto something here with the SSW phenomenon.
High pressure pushes everything away, meaning deep lows from Antactic
drifting closer to us & unfortunately NZ south island? Any one care to comment?
Long range forecasts for Auckland has a couple of windy days Sept 14 & 15
also 29 & 30.

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#1208759 - 31/08/2013 22:30 Re: Deep Southern Ocean Low [Re: Nerd65]
Nerd65 Offline
Weather Freak

Registered: 30/01/2011
Posts: 446
Loc: Cranbrook, Townsville
Hi All. This is the chart I was referring to:



The direct link is: http://www.bom.gov.au/fwo/IDY00030.201308301800.png although I don't think the BOM keep these coloured charts around for very long on their server.

According to ACCESS-Global the low weakens and skirts the Antartic mainland over the next day or so.
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#1208761 - 31/08/2013 23:30 Re: Deep Southern Ocean Low [Re: Nerd65]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 3184
Loc: Tweed Heads
936hPa at about 52 deg Latitude and 120 E longitude.

Not sure of the record? Laurier W would know .

Thanks for that chart.
There is currently quite a large upper low ( 200hPa..jetstream layer) around that area currently
So low pressure from surface to 200hPa at least . Likely to 10 hPa as a blob of stratospheric warming from the current vigorous wave action underway around the southern pole.
Haven't seen the sub polar jet all autumn or winter but there are glimpses of it there on that snap

As an aside. Notice the 3 upper lows in the NH atm.. Iceland due for a snow bashing atm
http://www.theweathernetwork.com/news/ar...-iceland/11854/

A snap of those upper 200hPa lows


[img]https://picasaweb.google.com/110600540172511797362/STRATOSPHERE#5918225681962981810[/img]

source
http://www.bom.gov.au/australia/charts/v...it=Refresh+View

Some of my photo files on this sub polar action

https://picasaweb.google.com/110600540172511797362/STRATOSPHERE#5918225681962981810

---------------------------

Nice picture of the beast on WZ sat pic' atm
I don't think they are equivalent to the tropical CAT beasts
But l can't remember why?
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Reports of snow in Brazil on the weekend of the 25th Aug
Probably associated with this SWW wave like action


Alex Shahviri
Staff Writer

Wednesday, August 28, 2013, 1:29 PM -

While Brazil saw some light snowfall this past weekend, on the other side of the world Iceland faces a much more serious blizzard in the coming days.




Forecasts for Iceland include very heavy rain and snowfall later this week. Those in the highlands are being advised to evacuate the area immediately.

According to the Icelandic Meteorological Office, both Friday and Saturday will hit the highlands hard for much of Northern Iceland. Along with heavy rain, there is expected to be snow over 200-300 metres (approx. 600 feet) above sea level.

http://www.theweathernetwork.com/news/articles/snow-falls-in-one-of-the-worlds-driest-areas/11834/




Edited by crikey (31/08/2013 23:32)
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#1208938 - 02/09/2013 21:00 Re: Deep Southern Ocean Low [Re: Nerd65]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 3184
Loc: Tweed Heads
NERD65..Here is the 10hPa stratospheric 'hot spot' passing OZ associated with that deep southern low you spotted and posted on the 30th Aug 2013.



I noticed from Petros's VIC post the GFS model is forecasting a cold incursion toward the mainland and you can see the wave action with a high pressure cell adjacent in the westerly belt.

This GFS forecast is showing the wave action around the southern pole nicely
See the high pressure aligned north /south sandwiched between the low pressure
THe 532 thickness line approaches the Vic mainland




Edited by crikey (02/09/2013 21:01)
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#1208960 - 03/09/2013 09:33 Re: Deep Southern Ocean Low [Re: Nerd65]
Blair Trewin Offline
Weatherzone Addict

Registered: 13/07/2001
Posts: 3982
Loc: Melbourne, Australia
The MSLP anomalies map showing now is the August one (the link has auto-updated).

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#1208968 - 03/09/2013 10:18 Re: Deep Southern Ocean Low [Re: crikey]
Laurier Williams Offline
Weatherzone Addict

Registered: 01/02/2001
Posts: 2192
Loc: Millthorpe, 970m, Central W NS...
Originally Posted By: crikey
936hPa at about 52 deg Latitude and 120 E longitude.

Not sure of the record? Laurier W would know .


A difficult one as firm records are difficult to establish. This extract from an [article at Wunderground] fits my understanding, though Blair may have more recent information. The low under WA appears to have reached greatest intensity of 936hPa on the 18UTC analysis last Friday (4am EST 31/8/13). This is not a measured figure - the nearest buoy was about 500km to the ESE with a reading of 962.4hPa - but would have been extrapolated from other buoy readings, satellite pics and possibly sea-surface [scatterometry]. The lowest pressure that particular buoy recorded was 951.1 at 09UTC 31/8/13 (7pm EST 31/8/13).


SOUTHERN HEMISPHERE: Barometric records for the many intense storms that develop in seas surrounding Antarctica are hard to come by and difficult to assess for accuracy. Blair Trewin of the Australian Bureau of Meteorology relates a value of 919 mb (27.14) from Casey station on the Windmill Islands (just outside the Antarctic Circle) on Vincennes Bay (6617S 110 31 E) on August 8-9, 1976. However, this is considerably lower than any other value on record and may very well be an instrument fault although he states the values are internally consistent with readings below 940 mb from 1600 local time on August 8th to 0700 on August 9th.

Aside from this remarkable figure the lowest other readings from the region include 934 mb (27.59) at Halley Bay, Antarctica on Aug. 11, 1994, 942 mb (27.82) at Grytviken on South Georgia Island (54 16S 36 30W) sometime between 1929-1964, and 945.1 mb (28.17) at Campbell Island located about halfway between New Zealand and Antarctica (52S 69W) on July 18, 1982.
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#1209041 - 03/09/2013 21:50 Re: Deep Southern Ocean Low [Re: Nerd65]
Petros Offline
Meteorological Motor Mouth

Registered: 30/12/2002
Posts: 8058
Loc: Maffra, Central Gippsland, Vi...
Thanks for an interesting thread here all.

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#1209152 - 04/09/2013 21:52 Re: Deep Southern Ocean Low [Re: Nerd65]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 3184
Loc: Tweed Heads
Thanks for the information Laurier. Absolutely Appreciated and interesting!

Thanks Blair for the notification of the MSLP anomaly update.


Here is both JULY and AUGUST 2013 MSLP anomaly side by side

Noticed that New Zealand had a POS+ 10 ! high pressure anomaly in JULY , a contributing factor to record winter warmth in NZ.
clearer skies.
Probably noting also just how far south those high pressure anomalies are.

JULY 2013


AUGUST 2013



Edited by crikey (04/09/2013 21:57)
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