APRIL 2022 - DO WE SEE AN EASING TREND IN RAINFALL AND HUMIDITY IN THE EAST AND RAIN COME BACK WEST?

The weather has been remarkably stubborn in recent months with the persistent positive SAM phase reducing the east to weather more of what you would experience in the far north through Summer time. The weather as we edge in March will likely continue those trends, no shift in the idea over coming weeks of increased humidity, above average rainfall for the east with a drier as you go west theme, and hotter too, through to WA.


It has been a stunning week of weather across the east and north with a set of records broken from humidity values to rainfall records through to flood levels. Some places eclipsing the mega rainfall events of the mid 70s. So we have seen quite substantial weather throughout the east.


But does that continue? And what about for the west, do we see a break developing there from the dry heat and above average temperatures with below average rainfall as we move into April??


A first look at April with a broader update to come Mid March as we get fresh data and this forecast will be adjusted in 2 weeks.


FORECAST


% chance of exceeding or not exceeding the median rainfall for the month of April 2022

Rainfall likely to be above average over the northern and more particularly the eastern parts of the nation as the carry over of the La Nina waning and the positive SAM impacts persist into early parts of the month. The rainfall chances over the north, leaning above average with the risk of a late season monsoonal burst north of the nation possible in the first week of April before that eases and the build down commences. Some of that moisture could be drawn over inland WA and the NT, through to SA and the southeast if we see a tropical entity take a journey out of the north. That does happen late in the season so that will be a wild card feature to watch. The weather for much of southern Australia looking seasonal, no strong bias either way at this point in time from all the data sets. The weather over the east is likely to be very wet, with that wet phase likely to ease from around Easter onwards. Always have to watch for ECL development as we are moving through this period into the peak of ECL season which runs through to the end of June for NSW and QLD. Finally, the month is usually one of transition for southern Australia and indeed northern Australia. As the airmasses clash in this process, there can often be wild weather with large rainfall events (bit like Spring) but occasionally, this process can happen without a whimper of severe weather and large rainfall events. With the climate drivers as they are, we could see a higher risk of severe weather during this process (usually late Autumn from ANZAC Day onwards) - there is no way of being specific, but something to just have in the back of your mind if you live in southern and eastern Australia and are forward planning.

% chance of exceeding or not exceeding the median temperatures for the month of April 2022

Cooler than average weather for the east coast with onshore winds and wetter than normal weather forecast. The cooler bias sharper through the first half of the month for the east before it eases through the latter part of the month. Once westerly winds become established, that may see drier and warmer air that builds through WA and SA be spread through the eastern inland ahead of frontal/trough weather coming through the Southern Ocean. The north and northwest of the nation warmer than normal with elevated humidity values to persist (product of the waning La Nina). So the build down may be drawn out for northern Australia. If you are in the white, that signals no bias either way, the data fairly settled on most areas looking seasonal at this time.

Key Points

The key points that headline the month and as mentioned above, I will have more on this in the coming fortnight as I wait for more data. But there is the preliminary points and forecasts above.

A refined and larger update for April 2022 will be posted here in 2 weeks time but this is a heads up for those planning into Autumn.

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