The Australian monsoon trough intensifies
Over the past couple of days, a strengthening Madden-Julian Oscillation (MJO) has led to enhanced convection over much of the Maritime Continent. North of the Equator, Tropical Storm Washi intensified, rapidly causing flash floods over southern Philippines. TS Washi is expected to track southwest over the South China Sea during the next few days.
The majority of climate models surveyed by the Bureau of Meteorology suggest that this MJO event will remain active around the Maritime Continent, contributing to tropical rainfall activity over the next seven to fourteen days.
A weak monsoon trough intensified north of Australia over the weekend, leading to enhanced convection across northern parts of the continent. An intensifying monsoon trough and an active MJO in the Maritime Continent increases the potential for tropical cyclones in the Australian region, with some numerical models predicting the formation of a low over the Arafura Sea and another in the Coral Sea later this week. The Bureau of Meteorology will be monitoring the situation very closely.
http://www.bom.gov.au/climate/tropnote/tropnote.shtml

That's last weeks. New one still not up yet.

Here is the updated one, a little late in the day.

A strong SOI continues in the Pacific
La Niña remains established in the Pacific with little change from last week. Atmospheric indicators of La Niña continued to intensify slightly, thanks to below average Mean Sea Level Pressures (MSLPs) at Darwin. The 30-day Southern Oscillation Index (SOI) value was +23.1 to the 24th of December, with contributing pressure anomalies of +2.3 hPa at Tahiti and −1.9 hPa at Darwin. The monthly SOI for November was +13.8, the highest monthly value since April. The 5-month running mean (centred on September) was +9.1.
Below average sea surface temperatures (SSTs) and sub-surface temperatures persist across the tropical Pacific Ocean. Data from the NINO3.4 region shows SSTs remain 0.8 °C below average, with no change form last week. Cloudiness near the International Date Line continues to be below average, but the area has expanded south of the equator. A well developed South Pacific Convergence Zone (SPCZ) extends from the Solomon Islands, over New Caledonia through to the south of Tonga. A large area of enhanced convection is evident from the southern tip of India, through northern Australia and the SPCZ.
Forecast models surveyed by the Bureau suggest this La Niña event is likely to persist for the majority of the north Australian wet season. It is unlikely that the current La Niña will be as strong as La Niña event of last wet season.
La Niña periods are typically associated with above average rainfall across northern Australia during the wet season, with an earlier monsoon onset in Darwin (which usually arrives around Christmas / New Year). Daytime temperatures are typically cooler from December onwards, and tropical cyclone activity is usually above average between November and April
See the Bureau's ENSO Wrap-Up which includes a compilation of ENSO computer model predictions.
Australian region nurtures first cyclones
Over the past couple of days, a strengthening Madden-Julian Oscillation (MJO) has led to enhanced convection over the southern Maritime Continent. An erratic MJO has been quasi-stationary around the Maritime Continent since early December.
The majority of climate models surveyed by the Bureau of Meteorology suggest that the MJO will remain active around the Maritime Continent, contributing to tropical rainfall activity over the next week as it propagates east.
Early last week, a tropical low developed over the Coral Sea into Tropical Cyclone Fina within the South Pacific Convergence Zone but lasted just a few days. Later in the week and with the monsoon trough over the Arafura Sea, a low gradually intensified into a tropical cyclone. TC Grant contributed to above average rainfall, flooding and strong winds across the Top End during Christmas. Now as low over land, ex-TC Grant is expected to travel east and may intensify again over the Gulf of Carpentaria later this week.  Above average rainfall and strong winds will continue across northern parts of the continent until early January.

It's my understanding SST's in the CS and Gulf are above average (and clearly rising in the CS). And the fact that the MJO continues to waddle around indicates some interesting times over the few weeks.
http://reg.bom.gov.au/products/IDYOC049.shtml

MJO to weaken over Pacific
After a brief stall over the Maritime Continent last week, the Madden-Julian Oscillation (MJO) increased in strength and pushed eastward into the Western Pacific. The MJO added to the already enhanced convection within the SPCZ. Furthermore, enhanced westerly flow in the wake of the MJO encouraged monsoon activity over northeast Australia.
The MJO is forecast to weaken as it moves eastward throughout the rest of this week. It is typical for an MJO pulse to weaken over the Eastern Pacific during La Niña events; this is most likely due to cooler SSTs and enhanced easterly winds at lower levels.
When the MJO pushes into the central and eastern Pacific it typically allows for a break in the North Australian Monsoon. Even with a weakening MJO signal (meaning the MJO will be less of a factor in driving the monsoon) it is likely that monsoonal conditions over northern Australia will subside for the remainder of the week.
See the Bureau's MJO Monitoring for more information, including rainfall maps.
http://www.bom.gov.au/climate/tropnote/tropnote.shtml

An erratic MJO over the Pacific
Over the past seven days, a weak and erratic Madden-Julian Oscillation (MJO) remained in the western Pacific contributing, in some small measure, to convection within the northern flank of the South Pacific Convergence Zone (SPCZ).
The MJO is forecast to remain weak, but progress eastward throughout the next fortnight. During La Niña events, it’s typical for MJO pulses to weaken over the eastern Pacific as they encounter below-average SSTs and enhanced easterly winds at lower levels.
Drier than average conditions are expected over far northern Australia as the monsoon trough migrates north and extends from the Arafura Sea to the Coral Sea. These drier than average conditions are expected to last at least until late January. In contrast, northern WA and the south western NT can expect above average rainfall and gusty winds in the next few days as a trough draws in moisture from the tropics. A low pressure system over the North West Shelf is expected to intensify before heading south over land. At this stage, it is unlikely this low will develop into a tropical cyclone.
See the Bureau's MJO Monitoring for more information, including rainfall maps.
http://www.bom.gov.au/climate/tropnote/tropnote.shtml

The MJO has re-emerged into phase 5 after a period of dormancy. It will be interesting to see how it interacts with the developing monsoon trough.

Yeah definately keen to be watching what it does. Surprising its been so dormant when over near Madagascar they have two very active systems and the convection across Australias tropics is deepening more and more by the day. I would imagine there will be rapid deepening of that MJO signal over the next few days. Otherwise I will just be plain confusd if it doesn't.

australian continent is like a magnet for the mjo during lanina, finally the map is showing this

http://cawcr.gov.au/staff/mwheeler/maproom/RMM/phase.Last40days.html

very nice amplification there ... sooo looking forward to a good rain event
cheers

I have started a new thread here for any discussion of the NT monsoon low:

http://forum.weatherzone.com.au/ubbthreads.php/topics/1063985#Post1063985

The MJO signal is quite significant at the moment and is firmly in phase 5 atm. This has really kicked along the monsoon trough which has spawned several lows, including a monsoon trough over the NT which is forecast to interact with an upper trough and have a significant affect on central parts of Queensland and NSW.

Monsoon returns to northern Australia
A deep and well organized trough formed last week over the Arafura and Timor seas and gradually migrated southwards towards central Australia, bringing an active monsoon to our latitudes. At the same time, the Madden-Julian Oscillation (MJO) gained strength and propagated east across the southern Maritime Continent. The MJO is currently positioned over the western Pacific Ocean. There is some degree of uncertainty on the positioning and amplitude of the MJO in the forthcoming weeks due to the influence of La Niña, but it is likely to contribute to enhanced storm activity within the SPCZ including the Coral Sea.
Over the next week, monsoonal conditions will prevail over northern Australia with above average rainfall and enhanced low-level westerly winds. The Monsoon trough is expected to migrate north and reach the base of Australia’s Top End later this week. Off the Western Australia coast Tropical Cyclone Iggy is expected to continue on a southwest track. Over the Australia’s eastern seaboard, a low is likely to develop over the Coral Sea by the end of the week although at this point it is too early to predict its strength or possible track.

YS, where is that story from? Please remember to provide a link to the source of the information.

the BOM must be seriously under staffed? i checked the weekly tropical climate note at 7 am this morning and it still had not been updated (it is normally updated every Tuesday) i checked it again an hour later and it had been updated, the funny thing about that is that the date on it had been backdated to "Tuesday" the 13th......but Tuesday was actually the 14th!


Drier conditions return to northern Australia
Drier conditions have prevailed over northern Australia as the North Australian Monsoon (NAM) remains in a break period. Agreement between the models continues, suggesting the MJO will remain strong over the next two weeks as it progresses from the Atlantic into the Indian Ocean. Current guidance suggests it will not be back in Australian longitudes until late February or early March.
Drier than average conditions are expected to continue across northern Australia for the next one to two weeks due to the break conditions of the NAM and the forecast track of the MJO. A pocket of dry air over most of northern Australia will ensure little rain for the coming days as daytime temperatures in central Australia climb to the high 30s and low 40s.
Over the Coral Sea, severe Tropical Cyclone Jasmine tracked in an east to southeasterly direction over the past week, bringing strong winds and torrential rains to parts of New Caledonia and Vanuatu. TC Jasmine reached category 4, the strongest so far in the 2011-2012 season. The Fijian meteorological service is monitoring TC Jasmine as it continues across the central Pacific. The chance of tropical cyclones forming in the Australian longitudes will remain below average over the next week.
See the Bureau's MJO Monitoring for more information, including rainfall maps.
http://www.bom.gov.au/climate/tropnote/tropnote.shtml

Noticed the monsoon trough is no where to be seen on the synoptic chart atm. It is well out of sight
Is that caused by the MJO or ?
What makes the monsoon trough inactive? It was only active for a very short time in january

a MT forms when monsoonal cross equatorial Nth West winds meet the SE trade winds from southern Australian highs. we have only had one real strong NW burst this season, in early February. We have lacked strong high pressure systems in the tasman sea especially this season. the Qld area being dominated by upper and surface troughs. so there has only been the one short window when the classic monsoon has formed to date.

the MJO is seperate to the MT. But also the same! The MT can be strong and bring good rain events to northern australia, seperate from an MJO event. While the MJO over northern australia will also increase monsoonal activity.

should also note, strong monsoonal NW winds are driven by large 1040+hPa highs over siberia. If there are no strong low pressure belts between mainland asia and Australia, thats when we get the best out of the MT. if your looking at models in summer, look at Asia and watch for very, very big high pressure system!

Thanks for that. Mick 10..
also
Does the N/west to ..s/east tropical infeeds ( cloud band) traveling toward the mid latitudes) come from the MJO position or quadrant
I noticed there have been no tropical cloud infeed since the MJO has shifted east.

For example the recent floods in QLD and NSW.
Was that because the MJO was near the gulf of Carpentaria where the persistent moisture laden cloud stream appeared to be emanating from?

In Victoria we have missed the N/west cloud bands this summer
Last the n/west incoming tropical cloud gave us some decent rain
Is the MJO in the wrong position for an infeed from the N/west corner of WA?

Oh well, not to worry, there is always next season.

Looking at the satellite imagery it looks like a return to November i.e. widespread convection over South East Asia and sporadic isolated convection over northern Australia. The depression in the South China Sea is apparently receiving a bit of impetus from a NE monsoonal surge. Hopefully that surge will give us a bit of activity in a week or so.

Crikey ,
NW infeeds into VIC are typically an Mid Autumn - Early Summer Gig . They will be influenced by an MJO , but not the MT as much .
BUT all of this ( position of MT and MJO Peaks ) has all to do with the IOD ( Indian Ocean's version of ENSO [ so to speak ] ) .
There is a Thread in the General weather section that will explain IOD . Or if your lucky , PM ROM . Generally i think it would be wise to read that Thread first then Fire questions at himself or if he's busy ( AGW fighting ) then I can try and answer any questions you have .

Link " http://forum.weatherzone.com.au/ubbthreads.php/topics/42457/The_Indian_Ocean_Dipole_and_th#Post42457 "