Get Your MJO On
Get Your MJO On
While the southern states are shivering under relentless polar intrusions, to the north of the country it looks like we'll see increasing tropical activity into the final week of the year.
It's time for a little refresher on the bringer of tropical instability - the Madden-Julian Oscillation (MJO).
As the Southern Hemisphere transitions from spring into summer, the sub-tropical high pressure belt shifts further south. This is in reaction to the warming and expanding air in the tropics, and the westerly storm track retreating towards the pole.
Meanwhile, Central Australia also heats, creating areas of low pressure (because hot air rises) which draw in north-west winds from the tropics. This reversal/switch of winds from south-east trades - linked to the seasonal position of the sub-tropical high - to the north-west is known as the monsoon. Also, the area of convergence between the south-east trades and north-west breezes is called the monsoon trough.
The north-west winds usually contain moisture, transporting it south from the tropics, while the south-east trades are comparatively dry. Hence the arrival of tropical moisture during late spring/early summer to northern regions is linked to the north-west monsoon.
The bulk of the moisture falls along and north of the monsoon trough, however it isn't consistent; there are active and inactive phases. These phases are linked to a wave of tropical activity that circles the globe called the Madden-Julian Oscillation (MJO).
When the MJO becomes active, it activates the monsoon trough, bringing increased instability, moisture, and tropical storms. If conditions are favourable, we'll also see the formation of tropical cyclones. Favourable conditions being sea surface temperatures over 26.5°C and weak upper atmospheric winds (wind shear).
Currently the MJO is inactive but it's forecast to increase in intensity while passing through the Indian Ocean next week before moving towards the north of Australia and the Coral Sea around Christmas time.
Below is a forecast chart for the MJO. The further away the lines are from the centre, the greater the intensity of the MJO. The multiple shaded lines indicate varying model forecasts (ensemble), with the mean of the ensembles shown in black.
MJO ensemble forecast for the coming weeks. Note the black (mean) line moving into the Australian region while intensifying (spreading out from centre)
Making sense of the above MJO forecast, we'll likely see a couple of weak tropical systems forming in the Indian Ocean during the coming week ahead of a more significant system in the Coral Sea into the last week of the year.
The formation of any tropical storm relative to swell potential depends on a lot of wide ranging factors, but keen weather watchers will have plenty of time to peruse the long-range charts over the coming fortnight.
Hopefully the MJO behaves as forecast, gaining strength while moving to a position north-east of the country. If it does, the chance of a late Christsmas present are very high.
Comments
Interesting read, delved into meteorology a bit for my coastal engineering degree and found it really interesting. Been keen to gain a better understanding so I love these articles you guys put up discussing this, IOD, SAM etc.
Also frothing for some waves hahaha
Farkin cold here in South Oz... Farkin beanie on IN DECEMBER!!! Warm in the sun but when it disappears... Oooo it's chilly
Beanie and jumper today singlet and thongs for the next few days, bullshit weather and bullshit waves.
Typical Top End xmas..
Once thought the Gulf was like a vacuum sucking moisture inland...
There are guys whom ride 500ft wind waves up there...
Well written but the mjo is not in the phase marked on the plot.
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Anthony Masiello
@antmasiello
The MJO is not in the IO. It is in the Maritimes and will continue to progress into the Pacific for the remainder of the month. Extratropical feedback helps extend Pacific Jet/anticyclone eastward. The PNA signal is real (in case you had any doubts).
6:59 AM · Dec 15, 2022
Interesting. Would like to see the proof? He's just stating that with no data.
Everything I see is pointing to it being around the Indian Ocean region, outgoing long-wave radiation is being reduced there and we're seeing anomalous westerly winds at 850hPa as well.
Also this is a handy chart to show the location of relevant forcings. Black solid line = MJO.
Cruisin, here is the BOMs climate note from one week ago:
"Multi-week forecasts indicate atmospheric conditions will likely become significantly more favourable for rainfall across northern Australia in the coming fortnight. There are indications that monsoonal conditions, widespread rainfall and cooler weather may develop near northern Australia. One component of this is related to favourable Madden–Julian Oscillation (MJO) activity, while a strong burst of cross-equatorial winds heading towards northern Australia from the northern hemisphere is expected to complement the influence of the MJO. Both ingredients are historically associated with active monsoonal conditions, and they are both predicted to develop in 1-2 weeks. If this occurs, it would be in line with the average monsoon onset date at Darwin in the last week of December"
http://www.bom.gov.au/climate/tropical-note/
Here's the BOMs Climate Driver Update from Dec 20:
"The Madden–Julian Oscillation (MJO) is expected to move across the Maritime Continent and Western Pacific regions over the coming fortnight, which may lead to increased westerly flow and rainfall across parts of northern Australia. The influence of the MJO may lead to the onset of the Australian monsoon during this time, while also increasing the risk of tropical low and cyclone formation across the region."
http://www.bom.gov.au/climate/enso/
Canm RMM1 17/12/2002. Unfortunately this site has no feature to post the plot data graphic
MJO appears as a very weak signal in pahse5.on the plot. Also take a look at live satellite data
you can see where actual convection is. .
Agree. Currently weak and hard to discern where exactly it is right now. Convection south-west of Java resulting in TC Darian looks to be linked though. Regardless lets hope it strengthens as forecast when it moves into the Western Pacific.
Our friends up north have some good images on there met service page sat images and wind plots.
Scrolling down from the top of the page you find em. Very cool looking eq rossby wave (n-1) north and south of the eq shown on a plot. There be the link to the mjo on that plot. Cyclonic cloud curvature also noticeable over nth of the top/end on real-time satellite.
https://www.bmkg.go.id/?lang=EN
https://earth.nullschool.net/#current/wind/isobaric/850hPa/orthographic=...
https://www.atmos.albany.edu/student/abentley/realtime/subtrop.php?domai...
Some more realtime data atm supporting above. This data will how ever change as day pass.
Irro wind shows the signal in the maritime nth of the topend. Should be enough data now to give a decent hint for anyone interested ..
Tropical Cyclone Darian, perfection..
Wow i did read somewhere you are a meteorologist Craig. No affence intended man but perfection?
lopsided with ragged eye on that satpic.
You set the bar way to low atm with this storm perfection is 140kts sustained cat5 for a tc with a perfect even symmetric eyewall.
Hard taskmaster Cruisin!
Maybe he likes the asymmetric features of the cloud bands?
Haha, you take things a little too literally. I am just admiring the cloud bands.
https://imgur.com/a/dnHY18x
Darian
Not for me needs alot of work for perfection.
The other storm Invest 90S brewing closer to the main land up north maybe the one to watch if it gets some shear free conditions.
Darian got its act together over night. Currently on sat appears to have been dropping the banding
and gone annular in structure huge improvement over 12hrs.
CI# /Pressure/ Vmax
7.0 / 921mb / 140kts
Nice to have a TC afficionado in the place Cruisin.
Beautiful!
Bit of cloud in the eye Craig- 5/10
Ha!
Cloud seen within the eye on the sat posted appears to me to be likely the initial beginning of the onset off a eye-wall replacement cycle. When it does complete the system may well have huge eye span in n/miles. How long it does take with all going well is anyone guess atm. They can be finicky
at the best of times. But yeah atm a very intense robust cyclone.
So, is NW Aus about to turn the fk on then or what !?
Nah, the bulk of the swell generating winds are on the southern flank..
Would be a nice swell producer for the Maldives if the storm track wasn't perpendicular through the window.
Haha was literally coming back to check which way the winds were spinning off it. Too bad, looks meaty as!
Head for this spot adsi:
https://goo.gl/maps/tuj1oa5oxvRWJuBa6
Hahaha surf potential not withstanding, it looks like a pretty nice spot!
Here's a great illustration of the South Pacific Convergence Zone. Area of convergence where south-east trades from the sub-tropical high meet the easterly trades in the tropics.
It's further south-west than normal owing to the La Niña signal.
Pretty
https://earth.nullschool.net/#current/wind/surface/level/orthographic=-2...
System to the nnw of the topend looking atm like a textbook monsoon depression. Has some ok midlevel rotation going atm. They can look sloppy but mostly always are a rain bomb when they find terra firma.
https://earth.nullschool.net/#current/wind/isobaric/850hPa/overlay=total...
Yep looks very interesting.
Boms tec
REMARKS:
Severe Tropical Cyclone Darian (category 5) continues to intensify and move in
a generally westward direction. Position is good based on satellite imagery and
microwave passes.
Darian continues to intensify, with increasing symmetry in the eye and surround
cloud structure. Intensity is estimated to be 120 knots (10-minute mean) based
on subjective Dvorak and consistent with objective guidance. Dvorak analysis
using eye pattern yields DT of 7.0 . MET with a D+ 24 hour trend gives 7.0. PT
agrees. FT/CI 7.0. Objective guidance estimates were: CIMSS ADT T6.7 132kt,
AiDT 131kt, OPEN-AIIR 127kt, NOAA ADT T6.7 132k (all 1-minute means). There
have been no recent updates to SATCON.
Darian is expected to continue moving westwards for the next few days due to a
firm mid-level ridge to the south, and will move into RSMC La Reunion's Area of
Responsibility this evening. The environment remains favourable with
well-developed outflow channels, low vertical wind shear and decent moisture
inflow at all levels. SSTs are near 27 degrees C, slightly warmer to the west
of 090E. The forecast intensity decreases slightly during Thursday as Darian
becomes a little disconnected from upper outflow, but then intensity may
increase again on Friday as an upper trough to the south increases ventilation.
From Sunday shear may increase and Darian should move south over cooler waters,
which should result in weakening.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by La Reunion RSMC.
Must be some waves on the East coast of Madagascar from it.
The Tropical Depression up North has got some massive convention busts going on sat.
Ens forecast track. Be some swell about if you are game enough to paddle with croc's.
Bubbling away.
Indeed it is brewing away. 18z hwrf thinks it may also wrap tight rapidly. Remains to seen in realtime if it get enough clearance to tho.
Possible tropical cyclone developing Friday morning before crossing the coast near the NT/WA border.
http://www.bom.gov.au/products/IDD65011.shtml
Realtime earthweather showing its cell now reaching upto 200mb so yeah that's the established ouflow point achieved with that it should do better overnight when the atmosphere cools.
250mb plot1 below.
plot2 mid-level winds and moisture feeds.
Just a heads-up though you're probably aware, Earthnull is all forecast data and not observed.
Infrared - Zehr have the glimpses of the cloud tops reaching -90°C. High, deep convection.
A few overshooting tops (towers) on visible above sat.
Think myself just viewing sat wont be long before the JTWC up grades this to a tropical storm. looks about 35-40kts atm to me i think.
Bom may take longer given they a bit tougher with classification.
No real surprise JTWC update with the upgrade . Cant be named until the bom names the cyclone being the officials in this AOR.
SUBJ: TROPICAL CYCLONE 06S (SIX) WARNING NR 001
WTXS32 PGTW 220900
1. TROPICAL CYCLONE 06S (SIX) WARNING NR 001
02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
220600Z --- NEAR 12.8S 129.1E
MOVEMENT PAST SIX HOURS - 190 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 030 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND RADAR
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
000 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
000 NM NORTHWEST QUADRANT
REPEAT POSIT: 12.8S 129.1E
]
Nice drink for the top end.
Yeah model totals for over a large region of the NT looking wet aswell the depression dragged the mt trough along with it.
BOM Ens plot 2
Great visuals!
FIFO mate of mine just got out of the region before the heavy falls.
The remnants of the former tc Ellie have been persistent over the Topend and now over nw WA. The remnants have had a lifeline to hang about from the mt feed. EC ensembles atm are weighted in the favour of a regeneration offshore re: plot1.
Access atm thinks the vorticity will not wet its feet again over warm waters offshore. It does however deepen the depression overland with the mt feed and see's the nnw feeder band re plot3 that is now fragmented hook up to the center of the vorticity. Access then see's a trough captures the inland depression tracking it in ssw track.
A pesky big wet slopy mess.
You familiar with the Brown Ocean effect Cruising?
Yeah indeed i'm aware of savanna landphoons.
Looks to be a classic case right now.
Is that the way you see it?
Yeah i agree with you on that current analysis. What will be interesting if the energy does go
offshore asper current ec ens think it may. Will it keep its former name. Or will it be tagged and renamed again with a different identity if ec ens verify the energy menders and don't get captured by a weakish passing trough and is steered by a building str.
Interesting scenario's on the table atm with this feature.
freeride76 SATURDAY, 31 DEC 2022 at 10:56AM
Looks to be a classic case right now.
Is that the way you see it?
Ellie
May well be something on the table with it around exmouth wa. Laters maybe for Jason Harris.
Hi all, can anyone here shed any info on expected rainfall for Bali mid to late January based off the current charts?
I’m thinking of going for a quick strike mission but won’t bother if it’ll be raining the whole time.
Thanks in advance
10TH to 18th looks ok atm to me re Bali rain question. The question may have been for Craig
not wanting to step on any toes here just my 2 cents.
Thanks Cruisin. The question was for anyone who has an idea of reading the the long term charts, because I have no idea…
Happy New Year to all and thanks for the hours of content SN
Nah go for it and thanks, I've been offline.
plot1 precip tally forecast over the next 4-5 days is at the end of the scale roughly 700mm on Broome's coast region.
EC atm wanting to give Broome a big drink and likely big gusts aswell when wind filters down.
looks on sat to be slowly developing even tho it's centre is on terra firma.
The bands on depressions can be hundreds of kilometers in length away from the actual centre of the low.
wsw wind speeds and shifts in coastal area's such as kuri bay suggests to me that this feature could be a well-marked tropical low by the official agency (BOM) however it's not classified as such atm.
AUSTRALIAN REGION (longitude 90E eastward to longitude 160E)
MSW Averaging Period: 10 minutes
Tropical LOW - term is used to describe disturbances ranging from
diffuse, ill-defined low-pressure areas all the way to well-
organized tropical depressions with MSW up to 33 kts
Tropical Cyclone - MSW in range of 34-63 kts/ Dvorak rating ranging
from a strong T2.5/weak T3.0 to T4.0
Severe Tropical Cyclone - MSW exceeding 63 kts/ Dvorak T4.5 or
higher
Impressive.
V. much so.
What's interesting to me is the way it has anchored and maintained the W-NW monsoonal flow across the top end and into CS.
In effect it has placed the maritime continent in the centre of a large semi-stationary monsoonal gyre.
Even tho quite a few hours old the last ssmis pass over the feature did show the embedded centre quite well.
It's hard for me to ignore. It's not classified as a tropical low locally. But that's just the way it is in our neck of the woods.
realtime radar tells the current story. Not sure what else they are looking at in realtime.
Shuggz enough from me.
Quote.
The head of WA's emergency services, Darren Klemm, has labelled the situation "the worst flooding event our state has ever seen", with authorities frantically working to rescue impacted residents. Ex-tropical cyclone Ellie has battered north-west Australia over the past week, with the Fitzroy River reaching record-breaking levels.
WOW to this dude. https://www.ski.com.au/xf/threads/2022-23-australian-cyclone-monsoon-sea...
Public interest Notice.
Steer Clear.
Wow it's doing the whole Do-si-do up north, still hanging in there.
re: two posts above.
Indeed, thus why not it's never a good idea to underestimate or belittle a tropical depression.
The continuous monsoon rains over the area were brought about by xEllie triggering massive flooding.
https://cleanet.org/resources/47829.html
Usually very up to date with plane, balloon, station data from the global forecast input data as it comes in and is assimilated into real-time wind data its claimed.
cheers.
Almost three weeks!
EC verifications data page.
EC eps ens forecast VPA displays a strong maritime mjo again in last last week of the month.
.
Walker cell circulation boosting maybe.
Yeah possibly.
Those trades keep coming and we didn't really seem to get much of a Nina killing WWB from the last MJO.
Yeah that's the chaos. Climate models relying on climatology algorithm's will keep showing plumes heading into neutral to warm territory. As you said kw's have just eroded way. And easterlies have dominated over the date line. With no wwb penetrating east of the dateline and the walker cell's position atm cooling the uppers. Myself until we do see evidence of kw's and wwbs and the walker cell shifting east the chaos in trying to predict the next 6 months inline asper the current enso modeling tools is doubtful, And they should be used with caution. Opinions are my own so don't give em any weight when coming to your own conclusions. I do like to see other people's opinions not just modeling. Hope it makes some sense.
Cheers.
It's fascinating to watch each Kelvin wave dissolve and the MJO being held off to the west as those trades keep going.
We'll be heading into some unchartered territory if it keeps persisting.
Likely the current flooding up North is being fueled by a west moving equatorial rossbywave.
lots of vertical uplift.
Re above.
With our audience you'll have to explain in a bit more detail exactly what you're posting graphically as most wouldn't be aware of the outgoing long wave radiation charts, and what to look for.
Or know what a Rossby wave is :)
The gyre (MG) setup appears to me to be because of the equatorial rossby wave's energy dispersion over the region. Craig is likely not to be happy with the lack of information without in depth detail with this post. Buts that's how i see it and how i roll.
Cheers
I've got no issues, it's just if you want to attract more engagement and discussion of what you're posting from the greater Swellnet community.
You're very knowledgable but for others to follow you might need to explain things a little.
Took me a while to decipher that second image.
Kinda cool to go down the rabbit hole searching for Rossby!
SAM, Kelvin and Rossby walk into a bar…..
Haha.
It's notable and seems weird that out of all the lows which have budded off the Monsoon trough in the last 3 weeks, not one has been able to form a cyclone.
Not even close.
Cruising, do you have a take on this?
Too much shear?
Yeah shear has been the killer. Futher east however nine has found some good conditions and is already a cyclone and most likely should ramp up. It was also embedded along the mt.
You can see areas that are hostile re shear on the above plot.
Love your input Cruisin. Sign him on SN.
Nine was named and upgraded overnight. https://www.vmgd.gov.vu/vmgd/index.php/forecast-division/maps-and-charts
Nice, yeah 92p looks to intensify to a TC now as well.
Yeah, welcome Irene.
Shame there's no recurvature.
If 92P undergoes cyclogenesis it'll be TC Freddy.
With more surf potential, at least for sub-tropical areas.
Yeah, the 92 disturbance is broad and very elongated. There is a westerly flag, so it is a closed off lpa atm. Worth keeping a eye on it for sure for any further consolidation overnight.
Purple time-stamp along the bottom is actual time of the samples pass.
Farewell Irene.
Chance of 92P being upgraded to TC status now high.
Goodnight Irene!
well played
92 has two competing vort's jumping around inside the circulation. One of them needs to locate with the other for 92 to get going. Very cool looking swpac monsoon gyre setup tho.
The gyre (MG) setup appears to me to be because of the equatorial rossby wave's energy dispersion over the region. Craig is likely not to be happy with the lack of information without in depth detail with this post. Buts that's how i see it and how i roll.
Cheers
We've seen Monsoon Gyre set-ups as a semi-permanent feature over the last month I reckon Cruisin, especially as a result (cause? effect?) of semi-stationary ex-Ellie.
For me my main interest atm is if the gyre instead of spitting out those multi se vort's the gyre itself becomes one large TC.
The mt was dragged lower over the continent by Ellie agreed. I don't recall seeing a large tilted nw to se gyre tho in the swpac.
Could be a good result for surf if it stays mellow.
Would be stoked with a week of 3ft clean mornings on the open beaches.
The MJO signal looks quite strong on the GFS plot above.
It's timing is almost in sync with the, EC eps ens forecast VPA displays a strong maritime mjo again in last last week of the month post plot on SATURDAY, 14 JAN 2023 at 6:18PM.
Yep, here comes round two.
Do you think the Broome region is going to cop it again?
Its a tad early to call any exact location atm anywhere along the stretch from, Derby to Karratha
maybe on the table atm with a possible landfalling tc in the next 2 weeks.
Would it be fair to say that the weather event currently impacting North Is. NZ is their version of a Black NE'er?
Nah, the wind strengths aren't there.
Ben Noll covers it well..
And to put it in perspective..
Thanks for the info.
The current setup looks mental. Could be a mess tomorrow.
RE: Gerg twitter repost. Its been widely known and stated by (legitimate) climate scientists many years ago we would see more extreme global weather events with climate change. The Pakistan Floods being a prime example.
Marine heatwaves are drivers also in many of those extreme events.
Actual land heat waves a different beast over our continent have always been a threat even in a cooler global past environment.
Quote
Historical heatwaves
Since European settlement, there have been 11 heatwaves which resulted in significant loss of life. Some of these coincided with severe droughts, such as the Federation Drought (1895–1903), the Second World War Drought (1939–45) and the Millennium Drought (2001–09).
The most catastrophic heatwave, which was responsible for the death of 435 people, occurred between 1895 and 1896 and covered most of the country.
Indeed!