The pattern is about to get stuck once again, meaning a stagnant synoptic flow expected to redevelop across the nation.

A positive SAM for the eastern and southern parts of the nation and an MJO in phase over northern Australia for the coming 2-3 weeks will lead to a wet period for these regions.

As we saw back in January, the persistence forecast with these drivers in play for 3-4 weeks brought heavy rainfall that lead to flash flooding. We also elevated severe thunderstorm outbreaks as well, with nasty conditions over many locations, mainly due to flash flooding.

It is rather conceivable that we could see similar conditions once again, but the magnitude of these remains to be seen. I do think there will be flooding redeveloping but the more likely regions will be over in the north and east this time around verses over central Australia which brought disruption.

If you are living out in WA, the weather for the SWLD and Ag Areas, dry and warm for the most part but some rainfall will feature later in this period, perhaps with the approach of the westerly wind belt. The drier signal may engulf a lot of SA if the MJO peaks over northeast Australia, meaning moisture will run through the east of the nation rather through the NT and WA. But will watch that more closely in the short and medium term forecasts over the next week.

Lets take a look at the latest details.

Rainfall Outlook - Next 6 Weeks.

% chance of exceeding or not exceeding the median rainfall for the next 6 weeks.

Not much shift in the guidance, with the east and north looking wetter than normal with the climate drivers in support of dragging in large amounts of moisture in the easterly winds (via the positive SAM) and the north thanks to the monsoonal pattern (via the in phase MJO). All of that will work together to spread moisture south and southeast through inland QLD and into NSW and the ACT, parts of eastern VIC as well. The areas west over southern Australia probably leaning more seasonal in terms of rainfall expectations through this period, however, as we have seen in recent days there have been indications that tropical weather may spill south with decaying tropical lows/cyclones through WA into SA and the southeast but the short and medium term forecasts will cover that specific off. Finally the east coast could see an aggressive start to the wet season with heavier rainfall a near certainty (not 100% chance ever in weather). The risk is also moderate for flooding to redevelop over northern and eastern Australia.

Temperature Outlook Next 6 Weeks

% chance of exceeding or not exceeding the median temperatures for the coming 6 weeks.

Not much change from Tuesday, but have extended the cooler than normal bias further west through QLD and NSW with the duration of the positive SAM likely to lead to prolonged rainy and cloudy weather with cooler than normal weather likely. The weather seasonal for the remainder of the southeast and east and over northern Australia. A warmer bias exists over the western interior thanks to the developing positive SAM and the pressure pattern becoming stagnant, high pressure being pushed south of the nation propelling easterly winds over the region.

Key Points

These points are covered off in the video. But be aware of the developing monsoon, the positive SAM and the impacts that are likely to come of that, more volatile weather in the short and medium term forecasts so refer to those twice a day and keep up to date with the latest information. This is an overview of the period ahead which will contain volatile weather that this forecast and analysis will not quite capture.

This product will be updated again during Tuesday morning.

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