MONSOONAL WEATHER INCREASING - IMPACTS TO SPREAD SOUTH THROUGH MARCH.

The monsoonal weather is already starting to develop north of the nation as we track a MJO pulse through the region over coming days and indeed the next 2 weeks. This will spice up the weather impacts over the north of the nation with the chance of tropical depression formation and then the risk of cyclone activity unfolding.


This is not uncommon at this time of year.


The monsoonal burst over the waters north of the nation is the perfect breeding ground for the cyclone formation, rather than the trough being over land which has been the case back in December and in January, where inland lows produced that record rainfall for many inland areas of Australia.


This event looks to favour heavier rainfall over northern parts of the nation and then the offshoot moisture will run south and southeast through the coming 2 weeks, bringing perhaps some above average rainfall to Outback areas of the nation and into the southeast. With a wet east and southeast of the nation, this will be additional moisture and rainfall risks on top of a wet phase that is already in place.


So flood risks over northern Australia will extend southwards through the nation, especially with landfalling tropical systems.


Lets take a look


FORECAST

Models and the Tropical Lows

The model split on the tropical low formation and then the movement of these potential lows is clear when you present it like this with the three major weather agencies that there is significant divergence. These are the paths that are being identified by the models and not all three agencies agree on one low so we need more time through the week to watch the data sets closely together. But each of these pose interesting outcomes in terms of spreading rainfall through the nation.

Tropical Depression Risk - This Week

With the monsoonal flow developing over the open water during this week you will notice larger clusters of thunderstorm activity. These clusters may become more organised and low pressure systems may develop. Given the elevated SSTs through the region (not as elevated as per January but it is sufficient) depression formation is quite likely from later this week and through the weekend. Refer to the chart to that shows you where the models are placing the tropical depressions and where they ago. The confidence in identifying the system that is the dominant tropical low is very poor.

Tropical Cyclone Risk - This Week

With the monsoonal trough sitting over the open water and the MJO passing through the north of the nation from the weekend and into next week, any tropical low that forms in the waters offshore the coast, carry a moderate chance of developing into a cyclone. The most likely outcome based of analogue data is that a system will form north of the NT and then head west through the Arafura, Timor and then Indian Ocean. That will then deepen offshore northwest WA and then turn towards the Pilbara and then inland through WA. That would spread heavy rainfall over the northern tropics but then pull the heavy rainfall shield away from the NT and over WA and another pulse of monsoonal weather would develop over Cape York.

DATA

Euro 12Z - Tropical Depression Risk

There is a relatively high risk of 2-3 depressions forming through the coming 2-4 days across northern Australia. Now how these evolve remains to be seen and which storm system is the strongest is not determined by the colours here, but certainly there is plenty to watch especially around the NT and north of QLD and off the coast of WA.

Then next week you can see the movement of the tropical depressions, as mentioned, travelling southwest through the Indian Ocean and the system over Cape York running over FNQ and then into the Coral Sea.

Euro 12Z - Tropical Storm Risk

Underneath this risk, there is a low to moderate chance of cyclone formation in these regions over the weekend and into next week but mainly offshore at this time.

So for now we watch. I am still in the tropics and looking at things on the ground and I can assure you things are starting to shift. The skies around the region are now in a state of transition and over the coming days I will have the inside look at the impacts not only for northern Australia but for the rest of the nation. Being based here helps me track the impacts for you across the nation.


I return to the southern Australia over the weekend so will be taking the moisture with me.


More soon.