Monday December 17

The MJO is now in Phase 3. After moving rapidly eastward the system has now slowed, similarly to the previous 2 MJO's. It should reach Phase 4 by the end of the week.

The Australian continental heat lows have been apparent, and the monsoon should be initiated by the approach of the MJO in the tropics.

4th December

The MJO is now in Phase 8. Central Pacific Easterly wind anomlaies have weakened with the passage of the MJO. Westerlies trailing the MJO are apparent over the western Pacific.
Convection is now suppressed through the Maritime Continent region .

The next passage of the MJO should reach Phase 4 about the 22nd of December, or in 16-25 days - a few days later than I suggested last week.

There is a very good chance that the next passage of the MJO will coincide with Australian monsoon onset.

27 November

The MJO is located in the western Pacific region. Easterlies, associated with the La Nina are inhibiting eastward movement. The MJO has demonstrated some eastward movement over the past week. With respect to the (fairly strong) Phase amplitude (Phase 6 amplitude 2.1 on 25th Nov) the westerlies that trail the MJO have moved east over the Indian Ocean and western Maritime Continent, and convection is strong: so, the amplitude is reasonable despite the lack of characteristic eastwrad movement.

I would now expect to see westerlies and suppression to the north of Australia however:
there is a La Nina in place, and that La Nina is still strengthening. The La Nina was late and Sea Surface Temps adjacent to Australia were cooler than would be expected during a La Nina event. These La Nina indicators make it very difficult to forecast the rainfall impacts of the MJO throughout northern Australia. While the MJO may be in an inactive phase and suppressing rainfall, this impact may be pretty much indecipherable due to La Nina driven convection and rainfall in the western Pacific/ northern Australia.

I expect the next passage of the MJO north of Australia (RMM Phase 4) in 18-23 days - mid December. Given the timing of this MJO event, and in conjunction with the La Nina, I would expect the Australian monsoon trough to develop in very short order after the arrival of the MJO.

MJO 21 November

Over the past week convection over the eastern Maritime continent and western Pacific Ocean has increased. This signal is to some extent a response to TC Guba, rather than as an expression of the MJO. However the MJO has demonstrated some eastward progression.

Conditions over Indian Ocean have dried out, and I would expect the drying phase to shift east to the Martime Continent over the next 10-15 days.

The next passage of the MJO north of Australia cna be expected around mid -December.
This timing could coinicde with the start of the monsoon, especially given it's a La Nina year, and the monsoon can reasonably be expected to be earlier than usual.

14th November

After rapid eastward movement, the MJO has settled over the Maritime Continent again (as during Sept - Oct) with little eastward movement evident over the past week or more.

Based on the last few MJO's the next passage would arrive north of Australia mid-December.

La Nina conditions may continue to dominate the MJO. Regardless of that, the next MJO could well intiate the start of the monsoon over northern Australia.

MJO Sitrep Tuesday 6th November

After moving rapidly east the MJO is now located in the Maritime continent region. This relatively stationary pattern is perhaps more La-Nina-ish than MJO-ish

The past few MJO's have displayed the typical 40-50 day timing and if this continues the next MJO is due mid-December, nicely timed to intiate the mosnoon.

October 30

The MJO signal has increased in strength during recent days after a very rapid eastward
movement from the western hemisphere to the Maritime continent. Convection has not yet shifted southward into the southern hemisphere.
While MJO signals should generally strengthen during the southern summer, and Australia see a more direct MJO impact, La Nina conditions can be expected dominate any MJO impact.

Sitrep 23 October

The MJO is due north of Australia early November. This could mean the first incursion of the rainy season (but NOT the monsoon) for much of northern Australia.
The monsoon might then be intiated be the next passage of the MJO, early-mid December.

The MJO is currently weak, but in the region of Phase 1. Phase 1 and 2 are associated with drier conditions in northern Australia during summer.

Fewer weak MJO signals occur during Austral (southern) summer. Phases 4-7 are associated with increased chances of rain across the north of Australia.

The MJO is in Phase 8.

The next passage of the MJO (to the North of Australia) is expected late October/ early November, and could be reasonably expected to initiate (pre-monsoon) early summer rains in the north.

In Australia, there is less direct impact from MJO passages during our winter/early spring. For example, during Phases 5 and 6 the southern grain belt (south eastern Australia) could expect enhanced chances of rain, and the western grain growing region winter rainfall is enhanced during MJO Phases 7 and 8. More 'weak' MJO Index signals, when Phase cannot be determined, are recorded during Austral winter.

The RMM signal remains weak. This incoherent MJO signal is unlikely to have any effect in northern Australia at this time of year.

The next passage of the MJO is expected late October, and at this time of year could be reasonably expected to initiate (pre-monsoon) early summer rains in the north.

In Australia, there is less direct impact from MJO passages during our winter/early spring. For example, during Phases 5 and 6 the southern grain belt (south eastern Australia) could expect enhanced chances of rain, and the western grain growing region winter rainfall is enhanced during MJO Phases 7 and 8.

More 'weak' MJO Index signals, when Phase cannot be determined, are recorded during Austral winter.

Weekly Update

The RMM signal remains in Phase 5. No eastward movement of the OLR anomaly has been apparent, however weak westerly wind anomalies have developed west of the maritime continent over the past few days. This incoherent MJO signal is unlikely to have any effect in northern Australia at this time of year, however the next passage of the MJO could be expected mid-late October, and influence the timing of the initial summer rains in the north.

In Australia, there is less direct impact from MJO passages during our winter/early spring. For example, during Phases 5 and 6 the southern grain belt (south eastern Australia) could expect enhanced chances of rain, and the western grain growing region winter rainfall is enhanced during MJO Phases 7 and 8. More 'weak' MJO Index signals, when Phase cannot be determined, are recorded during Austral winter.