CLIMATE - A REFRESHED LOOK AT THE END OF MARCH THROUGH EARLY MAY

We are getting into the very important period for many on the land, where are the temperatures going? When is the Autumn Break coming for those areas in the south and west that have not seen much Summer rainfall?


Are we at the risk of late season cyclone activity and how does that impact the nation as a whole? With an early seasonal shift a chance this year, does that increase frost risks into May?


So many questions are being asked and I want to flag those as the areas to cover off in the video this morning and the forecast charts below.


Also I like to look at the previous climate information and marry that to the current data sets to show you the consistency or lack there of and to give context to forecast confidence. So take a look.

FORECAST

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

As I mentioned on Tuesday in the update then, that these shoulder seasons in forecasting terms can be quite challenging given the mixed signals from the climate drivers, such as the SAM and MJO and whether they can be in phase bringing up the chance of larger scale rainfall events across the country. Now the models have softened the wet signal across the nation in this particular update but it does not mean that the period ahead is set to be drier. What it is suggesting is that the longer term forecasting remains of low confidence which is to be expected. The higher chances for above average rainfall for this period will be found over northern Australia with a significant degree of confidence on that. A moderate to high chance of above average rainfall for the east coast with the lingering La Nina. There is a low to moderate chance elsewhere for above average rainfall. More likely to see seasonal values for much of Ag Australia on the current guidance. But that said, the overall picture is one of volatility and as explained in the video, when you see the climate outlooks more volatile from run to run, this expresses a seasonal shift and an adjustment in the broader climate signals from the ENSO and IOD. Finally, expect the forecast confidence in the next 5-6 weeks to be low for much of the period.

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

I am not adjusting the temperature outlook that much from Tuesday, I do think we will see a gradual decrease in temperatures across the nation as we move from one season to another. But also I am anticipating the humidity to gradually decrease as well, with the lingering La Nina into May, likely to keep the moisture values up, so still a few weeks of tropical air for many areas away from the tropics seems a fair forecast. We have felt that this week. That will mean that overnight temperatures could be above average for many in the north and east. The drier cooler shift in temperatures is likely following the Autumn Break. Pinning down that Autumn Break for the west is like pinning the tail on the donkey, we just have not got rock solid consistent data on that just yet.

Key Points

Refer to the video for more information on the key points below.

Additional areas to consider

Other areas to consider as we move through the forecast period.

I will have another update on this on Tuesday but please refer back to the daily weather information to track the weather systems that are building on the horizon in the weeks ahead to bring the above average rainfall chances for large areas. And what are we seeing in terms of temperatures


It is Friday so the next update is the National Afternoon Update for the short and medium term - have a great day.



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