Uncertainty over potential of rain
AFTER last crossing Australian longitudes during late October and early November, an active MJO pulse is expected to move eastward across the Indian Ocean during the next week to fortnight.
At this stage though, there is a fair bit of uncertainty as to whether the MJO will remain strong or weaken as it approaches Australian longitudes.
The MJO is a band of low air pressure originating off the east coast of central Africa.
It travels eastward across the Indian Ocean and northern Australia roughly every 30 to 60 days.
It’s a useful indicator of potential rainfall events (but not amounts).
Across the northern half of Australia, especially during spring and summer, a strong MJO event can highlight potential periods of rain and act as a trigger event for significant weather events such as cyclones.
In the meantime, SOI values continue to remain in negative territory.
As of November 22 the 30-day average was minus 5.3.
This is down from +13.8 at the start of October.
For more information try usq.edu.au/icacs.