SA - LIGHT AND PATCHY FALLS WITH MOISTURE SCOOTING THROUGH - WATCHING THE TROPICS FOR MORE!

The weather over the state not as amplified as what was being forecast last week, as mentioned, needing to see one weather event off the board to then review how the next system responds to weather downstream, and now you see a much weaker system that is now forecast to move through.


We are left with patchy rainfall off and on through this week, but large parts of the state will go dry through Easter I suspect as ridging wins out.


Mild to warm and cloudy weather will be featuring much of this week with light rainfall about the states south as cold fronts clip the region.


Better odds for rainfall will be attached to the northern tropics and how that unfolds this week. If the moisture can run through to the Indian Ocean, it is more likely that it will be then propelled through the nation from northwest to southeast offering a large cloud band and areas of rain developing.


So we may have to wait one more week, which is not surprising to me hence why I said we would know more by the time we get to Sunday and not to count all our chickens. You can review where the forecasts were going last week and compare them to todays but looking back. The volatility in the forecasting will start to simmer down as the shorter term climate drivers sit neutral.


Lets take a look

FORECAST

Rainfall Next 10 Days

Rainfall is forecast to remain light and patchy for SA, mainly for the Southern Ag Areas and moderate falls are possible over the southeast areas during the period. Rainfall is likely to be hard to find over the remaining northern 2/3rds over the state. It will remain dry in these areas until moisture starts to turn south and southeast from northern WA or even the NT and then merge with instability running into the Southern Ocean westerly winds. This is where rainfall should return for larger areas and hopefully enough to water in crops, but this is still falling within seasonal expectations for April in SA.

MEDIUM TERM - APRIL 17TH-24TH 2022

Moisture Watch Next Week

Moisture spreading through northern Australia will work it's way into the Indian Ocean and then turn to the south and then southeast via the jet stream. The moisture will then have an opportunity of running into the southern ocean via cold fronts and troughs south of the nation, meaning that a large cloud band will set up along the thermal gradient and this is where we will see rain break out. This may reach southern SA towards SA and the southeast and east thereafter, if high pressure in the east allows.

Rainfall Anomalies

Rainfall anomalies all over the board in the outlook period which is par for the course this time of year. The tropics dictating the terms of rainfall spread through the short and medium and term. Above average rainfall to continue over northern Australia will spread southwest into WA. Moisture over the Indian Ocean will likely sweep into the jet stream and a cloud is forecast to form in response bringing rainfall to interior regions of the nation. How far east that comes is determined by high pressure over the east.

Temperature Anomalies

Temperatures are forecast to be above average for a fair chunk of inland Australia which is fair in relation to the placement of the upper ridge. Moisture rotating through northern Australia and over the Indian Ocean will lead to cloudy skies with scattered rainfall, some heavy. The southwest looking cooler than normal with persistent cloud cover and areas of rain with southerly winds. The east coast will see onshore southeast winds but rainfall should be light and more sunshine in between the cloud should see seasonal temperatures for now.

DATA - Refer to the video for further information and it is critical to keep check of the data sets to understand where the next major weather events are emerging from outside of this period. It may be quiet now but I am all about preparation and ensuring that information is shared with you as soon as it is available.


00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks

The active pressure pattern that was promised for some in the models last week, looks less likely now, as advertised, waiting to see how the system looked after we lost one severe weather event is critical, as you can see it is a very different and much less dramatic drier period for many areas. The tropics is where you find the active weather as you do across the southwest in the short term. More details on the daily break down in the video.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Moisture is a lot less than previous updates with a ridge now expected to stay in place. The moisture content over the north is near record values for this time of year and will result in above average late season rainfall, some areas could really benefit from that. Otherwise moisture near seasonal for most areas. But I am not placing too much faith in the medium term forecasting and so expect major changes to the forecast.

00Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z CMC - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis

A closer look in - note that it looks dry for many inland areas but this will likely change with the forecast guidance this week as modelling figures out what to do with the tropical incursion over northern Australia.

More coming up from 9pm EDT with a look at the models and rainfall, I will only share information that is in reasonable agreement as too much is too confusing and I only want to share what is plausible at this time, so stay tuned for that.




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