MIXED ODDS FOR RAINFALL OVER THE SOUTHEAST.

Low confidence forecast continues for the southeast of the country with various solutions on the table later in the week.


Rainfall for the next 10 days - Valid Monday 28th of June 2021

I am keeping rainfall largely unchanged for now through the region. We have seen the Euro model indicating a deep low forming through eastern Bass Strait, GFS has a deep low in western Bass Strait. Other models are showing just a wide upper low with multiple troughs about. So be aware that this rainfall chart will change as the position of the low and trough becomes clearer in the coming days. So don't get caught up on the apps and the raw data and start preparing to throw urea etc, it is too early to get into specifics with a more meridional phase of weather.

Before then, high pressure dominates, gorgeous sunny days after cold nights, pockets of heavy fog possible, Mildura reporting visibility less than 20m this morning, that fog may take a while to burn off in some locations over the coming days.


But that is really the only complication, with high pressure keeping things stable and settled, with light winds. For some, that is great news and a chance to dry out, for others it is only adding to the long dry spell/drought conditions in this region.


But now lets move onto the next wave of weather expected through southeastern Australia.


GFS Synoptic Pattern - 18z run - Valid Monday 28th of June 2021.

The cold front coming through later in the week, does offer at least some light to moderate rainfall for southern and southeast SA, some of that will spill over into the Ag areas. The shower activity also moving into VIC and southern NSW with light falls generally north of the divide. The wettest weather will be reserved for coastal communities. But note that there are further opportunities for rainfall in the outlook period with low pressure rolling through regularly. That will see light to moderate rainfall at times across the southern and eastern parts of Australia continue through to July. The talk of a blocking high over the east is now looking off the table, that is GOOD news for this part of the world.

This first front will have quite low thickness values attached to it, but a lack of moisture for inland areas will lessen the risk of low level snowfalls developing, even though the airmass is frigid. We will see showery periods but chiefly coastal with areas from southern SA, through VIC and across western TAS getting the best of the rainfall for now.


The Euro model does want to develop a low that is deeper and in a position that supports wetter weather for VIC and southeast SA, with more snowfalls possible for the Alpine Areas, but at this stage, it is the only one predicting this, so confidence remains low.


Euro Surface Pressure pattern with precipitation - Valid Monday 28th of June 2021.

Note the low is to the southeast of Gippsland and brings up a cold and showery airmass through to the southeast with bigger rainfall totals for VIC and southeast SA in contrast to GFS. It also would produce 70-100cm of snow which again I am not forecasting and most likely this low will be in a different position in this evening's run. I have not factored this solution into the rainfall forecast at the top of the page.


But what about this talk of further rainfall? What about the Indian Ocean? I can hear the SA fans asking those questions who have missed out so far.


Elevated levels of moisture coming through from the northwest ahead of fronts, is the key to winter rainfall through the nation this time of year, especially for areas such as SA and inland VIC through western NSW. We need to see cloud bands being drawn in ahead of frontal weather emerging out of the southern ocean to see this verify.


There are two events in the coming 10-14 days that does provide some hope of rainfall returning (I will talk more about this during the afternoon in a post about future rainfall in the coming 2 weeks). It is the second event that holds the most potential that is due through WA in early July that reaches the east from about the 8-9th of July.


Precipitable Water Values - Next 2 weeks - Valid Monday 28th of June 2021.

The precipitable water values paint an interesting picture beyond this week's event. There are two waves of low pressure being picked up most medium term global modelling and yes there are some divergence in the management of these systems, however the common theme assigned to them is the moisture injection from the northwest of the Indian Ocean. This will support widespread cloud and rain bands moving through from the northwest of the nation to the southeast, but who get's what is not being talked about yet. It is a heads up that there is rainfall opportunity emerging on the medium forecasting products. You can see the impact of the PW values and moisture profile over QLD with elevated levels this week, so you must surmise that similar events will emerge out of the west and northwest if low pressure evolves.

GFS Rainfall next 10 days - 18z Valid Monday 28th of June 2021.

So GFS rainfall for the coming 2 weeks shows that impact of a moisture feed coming through WA during the later part of next week and diving towards SA. That will be another feature to watch over the week to see whether the model continues to strengthen this signal. It is encouraging that we are seeing it repeatedly appear on charts as one system concludes and another commences, there are opportunities ongoing. That is what you want to see to verify the influence of the negative IOD that is underway. Bodes well for a wet end to winter and spring period.

You may see a lot of white over inland SA but that will start to fill in over the coming week or so with that moisture being picked up from the northwest of the nation. So standby for changes there.


The weather largely seasonal temperature wise, there is colder air filtering in later this week, but overall I wouldn't call it brutal cold weather. If a low does form over southeast Bass Strait, this could send in very cold and showery weather for southeastern parts of the nation but what one would expect for winter time.


Graziers forecasts will be issued later today for the events coming up later this week, the risk is moderate to high once again with the system moving in, for VIC and parts of SA and NSW.


Need more weather information? Email me at karllijnders@weathermatters.org where I can help you find a tailored forecast solution to supplement this baseline subscriber analysis. This may be sufficient for many, but if you need further drilled down information for your town or property, email me.



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