CLIMATE - REFRESHER FROM TUESDAY'S UPDATE.

No need for a video this morning as things have not changed that much from the update on Tuesday but you can see the information once again below if you missed the update.

The forecast rainfall and temperature guidance have changed ever so slightly to the video analysis, but there is very little I would change from the forecast analysis at this time. Next broader update on this product will be on Tuesday next week.


%Chance of exceeding or not exceeding the median rainfall for the next 6 weeks ending July 10th 2022

The rainfall guide remains largely unchanged for large areas of the nation with the wet bias connected to the Indian Ocean Dipole turning more negative. There are indications that the SAM may remain neutral to slightly positive but that remains to be seen and the international agencies handling of the ENSO is quite appalling quite frankly. Overall the ENSO will have less of an impact on the nation through Winter as the prevailing weather pattern is dominated by the westerly wind belts to the south of the country. Overall, I am not changing the forecast that much from Tuesday. Widespread rainfall is forecast to emerge over northwest Australia, streaming through the jet stream and into the southeast of the nation from time to time. The moisture turning into areas of rainfall, dependent upon whether we see frontal weather link into the moisture. But at this time, the signals for above average rainfall for many areas remains high and most of the southern Ag Areas can expect to see seasonal rainfall, moving into the wetter time of year, which will be useful. Over the east coast, models have been drying out the region in the short and medium term, but this could shift again, especially if we do end up getting a positive SAM phase, that lifts the chances of easterly winds and east coast low risks also are elevated. For now, the northern parts of the nation leaning wetter than normal, but that doesn't take much at this time of year given that is dry season. So, you may be seeing a lot of green on the charts, but it is misleading when you compare to statistical averages. Seeing green in areas that in their wet season is much more significant. I have adjusted the forecast down for the SWLD as we now move into Winter and the May averages are dropped.

%Chance of exceeding or not exceeding the median temperatures for the next 6 weeks ending July 10th, 2022

Still seeing a fairly warm bias over the northern parts of the nation where we have the elevated SSTs present, that thanks to the very long lived La Nina phase that refuses to pack up and leave. Looking out over the remainder of the country, there are areas of weak warm bias in pockets of NSW and really, that is connected to the potential for higher humidity values in between the frontal bursts and the possibility of easterly winds returning. The cooler bias is stronger back over in the northwest of WA and along the central coast, connected to the persistent signal from the modelling for cloud and rainfall to feature in these areas leading to widespread above average rainfall chances as well. That is the Indian Ocean influence impacting the region right there. If you are in the white zones, that is not me being lazy, that is just the data coming through suggesting that most areas will see seasonal values, not necessarily meaning that you won't have the cold blasts that we are seeing this weekend and next week. On the other side of the coin, we can see warmer days in these situations between fronts, with moisture and higher temperatures over northern areas of the nation being drawn south and southeast ahead of frontal weather.

Climate Drivers

The SAM is starting to play a more robust role as we move into the next 6 weeks and indeed through into about October, with a positive SAM phase leading to drier weather over southern Australia and wetter weather in the east, and the inverse occurs when the SAM turns negative. At this time, the SAM will be more in a negative phase, and this leads to wetter signals for southern areas of the country. The SAM tending more negative can also suggest that the La Nina is waning further with the result on the SAM becoming more variable rather than persistently positive. So that will be quite a telling driver. Otherwise, the Indian Ocean should continue to warm through this period with the major impacts from the IOD negative phase likely to be felt more as we move through Winter into Spring before resolving in late Spring into early Summer. The ENSO, likely to remain cool neutral with the warmer SSTs around the east of the country leading to elevated rainfall chances when the winds turn easterly and higher than normal temperatures over northern Australia.

Key Points

More details will be made on these areas on Tuesday.

Additional Points to Consider

These points will be discussed as we move through the coming weeks and months ahead, just so you know what areas to consider.

DATA - More coming up on this from Tuesday morning when the next lot of broad data is Issued


CMC Rainfall - Next 4 Weeks

Likely to see excessive rainfall over the northwest of the nation connecting into troughs over the western interior and cold fronts running through the westerly wind belt leading to higher rainfall chances sweeping through the interior and across the south and southeast. Near seasonal rainfall for much of the SWLD and the east coast could see a sting in the tail of the wet season, but further flooding for now is looking low through this period. Humid air persisting over the northern tropics.

GFS Extended - Next 5 Weeks

Tracking that heavier moisture load over the northwest of the nation across the 35 members, and that spreading into the jet stream and then into cold fronts, that seems to be the most plausible outcome over the coming month or so with the risk of above average rainfall running pretty high over the interior and near seasonal for the SWLD and a good chance of above average rainfall for the eastern inland.

CFS Rainfall - Next 6 Weeks

We are adopting that wetter signal via the westerly wind belt and moisture infusing the westerly wind belt with broader cloud bands developing with the risk of heavier rainfall than normal across the country. This is supposed to be the driest period of the year for many locations.

Euro Rainfall - Next 6 Weeks

On the single run below you can see that influence from the Indian Ocean running very high, leading to above average rainfall chances, possibly record values for some in WA, spreading throughout the country, but as I have been mentioning, does that moisture deviate southwards or does it go east? That this model cannot tell us with great accuracy. But looking nice and wet for southern Ag areas of the nation which is normal for this time of year and somewhat drier weather developing over the east, though some pockets favouring wetter than normal weather as is the tropics, representing the interrupted dry season forecast from January here.

The broader data set from the Euro, also very wet with the chance of flood issues over the WA interior and possibly developing over the southeast parts of the nation with rainfall rates and frequency increasing over wet catchments.

The next video on this product coming up from Tuesday morning next week.




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