The MJO signal should become more coherent.
The MJO should reach the Maritime continent in 15-20 days, when we will probably see the last 07-08 summer monsoonal burst.
Tuesday, March 4, 2008
Tuesday, February 26, 2008
The MJO signal is incoherent with cloud/ convective activity stretching from the mid- Indian Ocean to western Indonesia.
Models suggest that the MJO signal will probably remain incoherent for a few days.
I expect that the MJO will then cycle again, and reach Phase 4-5 (Maritime continent) mid March.
This may induce the last monsoonal burst for the 07-08 season, although there's always the chance a further passage of the MJO in April that could promote a final monsoonal incursion for Australia.
The probability of TC generation is enhanced by the passage of the MJO, so there's now an increased risk in the tropics to the NE of Australia for the next few days.
Models suggest that the MJO signal will probably remain incoherent for a few days.
I expect that the MJO will then cycle again, and reach Phase 4-5 (Maritime continent) mid March.
This may induce the last monsoonal burst for the 07-08 season, although there's always the chance a further passage of the MJO in April that could promote a final monsoonal incursion for Australia.
The probability of TC generation is enhanced by the passage of the MJO, so there's now an increased risk in the tropics to the NE of Australia for the next few days.
Wednesday, February 13, 2008
13th February
The MJO is now in Phase 5.
This passage of the MJO helped to re-invigorate the monsoon.
The MJO/monsoon should promote rainfall in northern Australia for the next week to 10 days, before the inactive phase of the MJO again suppresses convection. As previously noted, during a La Nina summer suppression may not be strongly evident.
The next passage of the MJO can be expected mid-March, probably the last opportunity for monsoon action, and wet season rains for northern Australia.
In addition to the MJO though: according to GCM's the La Nina may take a several months to break down, rather than breaking down over March - May, which may increase the chance of rainfall even through the ENSO autumn predictability barrier.
This passage of the MJO helped to re-invigorate the monsoon.
The MJO/monsoon should promote rainfall in northern Australia for the next week to 10 days, before the inactive phase of the MJO again suppresses convection. As previously noted, during a La Nina summer suppression may not be strongly evident.
The next passage of the MJO can be expected mid-March, probably the last opportunity for monsoon action, and wet season rains for northern Australia.
In addition to the MJO though: according to GCM's the La Nina may take a several months to break down, rather than breaking down over March - May, which may increase the chance of rainfall even through the ENSO autumn predictability barrier.
Tuesday, February 5, 2008
5th February
The MJO is now located over western Indonesia - Phase 4.
The monsoon should be reactivated in the north in a few days by the passage of the MJO.
The chance of a TC to the N- NW of Australia has increased.
The monsoon should be reactivated in the north in a few days by the passage of the MJO.
The chance of a TC to the N- NW of Australia has increased.
Wednesday, January 23, 2008
23 January
As the MJO continues eastward the monsoon trough is retreating.
Convection is likely to be suppressed over the next week or two.
The MJO is expected to initiate over the Indian Ocean over the next few days, and should arrive north of Australia (Phase 4) In around 3-4 weeks (mid February).
Convection is likely to be suppressed over the next week or two.
The MJO is expected to initiate over the Indian Ocean over the next few days, and should arrive north of Australia (Phase 4) In around 3-4 weeks (mid February).
Tuesday, January 15, 2008
The next passage of the MJO (Phase 4) can be expected about mid February.
The past 2 MJO’s have hung around in the western Pacific, slowing down markedly after their rapid transit of the Indian Ocean.
This MJO was perhaps a little slower, but seems to have hit the same hurdle in the western Pacific- it is probably the easterlies associated with the La Nina causing this Phase 6/7 sliding halt. In fact the westerly anomalies behind the MJO active convection look to have gone south around the equatorial easterlies this time.
Several tropical cyclones and tropical lows have developed with this passage of the MJO through the tropics north of Australia. There is probably still another 7-10 day window of heightened chances of a tropical Low related to this passage of the MJO. Then convection should be suppressed, however, given the La Nina, an obvious dry spell in the monsoon may not be very evident.
Over summer/ autumn the passage of the MJO will typically be associated with Southern Hemisphere tropical storms, and also cyclones in the Indian Ocean and western Pacific Ocean. We usually expect to see a greater impact on our rainfall (northern Australia) during our summer and autumn.
The past 2 MJO’s have hung around in the western Pacific, slowing down markedly after their rapid transit of the Indian Ocean.
This MJO was perhaps a little slower, but seems to have hit the same hurdle in the western Pacific- it is probably the easterlies associated with the La Nina causing this Phase 6/7 sliding halt. In fact the westerly anomalies behind the MJO active convection look to have gone south around the equatorial easterlies this time.
Several tropical cyclones and tropical lows have developed with this passage of the MJO through the tropics north of Australia. There is probably still another 7-10 day window of heightened chances of a tropical Low related to this passage of the MJO. Then convection should be suppressed, however, given the La Nina, an obvious dry spell in the monsoon may not be very evident.
Over summer/ autumn the passage of the MJO will typically be associated with Southern Hemisphere tropical storms, and also cyclones in the Indian Ocean and western Pacific Ocean. We usually expect to see a greater impact on our rainfall (northern Australia) during our summer and autumn.
Tuesday, January 8, 2008
MJo January 8th
The MJO is now in Phase 6.
The next passage of the MJO (Phase 4) can now be expected in mid February. The past 2 MJO’s have lingered in the western Pacific, after rapid progression eastward over the Indian Ocean basin. This is most likely due to the La Nina atmospheric signature in the western Pacific. The current MJO (Phase 6) might reasonably be expected to behave in a similar manner, and linger in the western Pacific for the next week to ten days.
At this time of year the MJO is typically associated with the Australian monsoon and increased rainfall over much of Northern Australian and also with features such as tropical cyclones. Several tropical cyclones and tropical lows have/are developing with this passage of the MJO through the tropics north of Australia.
As the summer progresses the passage of the MJO will typically be associated with Southern Hemisphere tropical storms, and also cyclones in the Indian Ocean and western Pacific Ocean. We usually expect to see a greater impact on our rainfall (northern Australia) during our summer and autumn.
The next passage of the MJO (Phase 4) can now be expected in mid February. The past 2 MJO’s have lingered in the western Pacific, after rapid progression eastward over the Indian Ocean basin. This is most likely due to the La Nina atmospheric signature in the western Pacific. The current MJO (Phase 6) might reasonably be expected to behave in a similar manner, and linger in the western Pacific for the next week to ten days.
At this time of year the MJO is typically associated with the Australian monsoon and increased rainfall over much of Northern Australian and also with features such as tropical cyclones. Several tropical cyclones and tropical lows have/are developing with this passage of the MJO through the tropics north of Australia.
As the summer progresses the passage of the MJO will typically be associated with Southern Hemisphere tropical storms, and also cyclones in the Indian Ocean and western Pacific Ocean. We usually expect to see a greater impact on our rainfall (northern Australia) during our summer and autumn.
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