I will have a broader update on July on Monday, looking at the breakdown of weather systems across the nation and a state by state look at that, for now, lets look at the coming 6 weeks overall as we move through the remainder of June into July.
We have seen the pattern flip in recent days from the dry weather in the west and the rainfall bias over the south and southeast, to now offer a more even spread of colder air and drier weather moving through large portions of the inland of the nation, finally bringing the drier break that many have been craving.
The weather over in the west offers an insight to what is returning, but also weather that has been active in the Coral and Tasman Seas, large scale cloud bands are the feature of the season! And these won’t just be sitting over the open waters, but translate over land through the months ahead and as you are here and reading these often, you understand that the risk of flooding is very elevated through Winter and into Spring, perhaps lingering into Summer.
For now, let’s take a look at the outlook for June 10th-July 24th, 2022
CLIMATE DRIVERS DASHBOARD
The main driver to watch here is the Southern Annular Mode and it's relationship to the developing Negative Indian Ocean Dipole which could see rainfall chances rapidly increase over western, southern and southeastern parts of the nation. This could also support a drier period over eastern, northeastern and pockets of northern Australia before we see moisture eventually spill into these regions from mid July.
%chance of exceeding and not exceeding the median rainfall for the coming 6 weeks
We could be looking at the driest period so far this year for large sections of the nation's interior which could extend into the southeast inland as well, with some areas recording below average rainfall values (marginally) but not widespread. The above average rainfall potential stays over the west and southwest with the deepening moisture profile emanating from the Indian Ocean and spreading through the jet stream and connecting with cold fronts. This will see the filling season continue at a seasonal to above seasonal rate for parts of SWLD of WA and this may extend into parts of southern SA.
EASTERN INLAND - NSW
Yes, I do own brown paints and it is appropriate to place some below average countours over the eastern third of NSW given that the SAM is forecast to be negative for the next 2-3 weeks leading to more westerly winds, drier air dragged through the continent and leading to above average temperatures returning at times. For those on and west of the divide, seasonal rainfall expectations are expected at this time. Now the forecast confidence at this time of year is not especially high and given we have got the Indian Ocean Dipole strengthening and the moisture values running through the jet stream quite high and the prospect of a higher thermal gradient developing, rainfall numbers quite flip on a dime in this region so do not be surprsied we see green appear again very soon. Overall a welcome drier 6 weeks which could be the driest period of the year.
SOUTHEAST INLAND AND VICTORIA
Signals for above average rainfall over much of Victoria with moisture and frontal weather colliding through the state with strong westerly winds being of influence given that the SAM is expected to be negative through the coming 2-3 weeks. That will support more rainfall for the southeast inland. A 55-65% chance of above average rainfall exists for many areas with a drier bias over in the east where a 65% chance of below average rainfalll exisits.
SOUTHERN AG AREAS
Generally seasonal rainfall expectations with most areas seeing light to moderate rainfall at times which should accumulate to average rainfall being achieved. The bias is a little higher for above average falls closer to the VIC border and below average towards the Nullarbor, but overall aiming for seasonal rainfall and if we end up with more, that would be a bonus.
Seasonal rainfall expectations for many locations through the coming 6 weeks, it could be that this becomes the driest phase in the weather for Winter before we see the Indian Ocean Dipole has a significant impact on rainfall for the second half of Winter. As mentioned, the weather is getting wetter as we go through Winter, though we started off with a bang with many areas recording average rainfall for June so far in the southeast and east after heavy rainfall at the end of May. Forecast confidence for this region is low to moderate.
The rainfall bias being well above average sits to the north of the SWLD and Ag Areas, but the chances have increased for much of the region with the Long Wave Trough set to camp over the region with persistent rainfall and higher moisture loads coming in from the northwest leading to excessive rainfall at times with cold fronts. A 75% of exceeding the rainfall is assigned to many areas but tapering off to about a 45% chance in the Eucla.
NORTHERN AND CENTRAL WA
Significant risk of above average rainfall is expected to continue but I have shifted the higher risk further south and also lowered the risk, the jet stream does look to have adopted a more southerly track with deeper moisture now expected over the western Pilbara and through the Gascoyne into the Lower West and Central West. The risk of flooding is low to moderate through this period as well. The moisture over the Kimberly is a lot less than the Top End but could kick off a few showers and storms at times. Rainfall chances sit at about a 65% chance of being above average over the deserts in the east.
The tropics are likely to see widespread humidity building offshore the north of the QLD and NT coasts which could lead to higher coverage of showers and some thunder over the course of the next 6 weeks. The rainfall could be heavier about the areas north of Weipa and through the island chains to the north of the Top End. Significant moisture may begin to spread south and southeast through the period, with the area of greater influence for the Barkly and Tanami through the Simpson districts connected to the weather over in NW WA.
Moisture loads as mentioned above is expected to drive some larger rainfall chances for this time of year, with a very deep moisture profile sitting offshore the northern coast of the nation which is expected to come into play during July I reckon, with more rainfall to develop with higher humidity for Cape York and FNQ. The rest of the state looking relatively seasonal but there may be some drier bias developing along the SE QLD coast, but this is a low confidence forecast relating to the drier weather.
%chance of exceeding or not exceeding the median temperatures for the coming 6 weeks
We are starting to see a shift away from that colder bias which is an indication that the Indian Ocean Dipole and the lingering above average SSTs are coming into play. Higher moisture loads working through the sub tropical jet stream is set to split the country in two through this period, with a warmer bias to the north of that jet stream and a seasonal temperature signal for areas to the south of the jet stream, but it is quite likely that the coldest weather for the period is being experienced right now before conditions warm up from next week.
The warmer bias is set to continue, despite the lovely dry surge right now, the warmer bias is starting to expand in response to the developing negative IOD which will fuel higher SSTs around northern and western Australia. This will lead to higher moisture loads, elevated temperatures and this meaning that the dry season may not be so dry and comfortable as we are used to.
Warmer bias building over northern Australia and that is thanks to the elevated SSTs that are currently surrounding the QLD region. This will lead to warmer and more humid weather through the coming 4-6 weeks, and once we lose the drier surge of weather during the coming week, things could turn rather humid again with above average temperatures featuring into July. Noting that the moisture values offshore are very high for this time of year.
The colder weather along the GDR will be linked to the cold outbreak we are experiencing right now but the warmer weather is not too far away and could persist through the coming weeks ahead. So, there may be some more red showing up across the reigon in future updates, so do not be surprised by that.
SOUTHEAST INLAND AUSTRALIA
Still have a slight cool bias that is mainly linked to the next week of weather, before we see a warmer trend developing from next week which could persist more often than not during the next 6 weeks which is a sure sign that the moisture and influence from the negative IOD phase is beginning to increase. Doesn't mean it won't be cold but the longest duration cold weather may be occurring right now for the season.
Seasonal conditions expected for most areas, with a warmer bias building north of a jet stream that will begin to carry more moisture and cloud cover linked to the developing and strengthening IOD phase. It is quite possible, we have seen the coldest burst of Winter so far IF the climate guidance is right, but not going to call that definitively just yet.
SOUTHERN AND CENTRAL WA
Noticing the cooler bias exists up over the Pilbara and Gascoyne extending inland but most elsewhere should see relatively seasonal temperatures as the Indian Ocean Dipole strengthens and sends more tropical and warmer moist air through the jet stream and this bringing warmer days ahead of strong cold fronts that will also bring colder days, but it does look like we are moving into the period where the IOD will begin to win out, so the brutally cold weather looking less likely for Ag Areas.
As mentioned, there is a bit of Climate information throughout the next few days including a broad outlook for July and leading into Spring on Sunday and Monday so take a look at that!
ALSO - I WILL BE ADDING RAINFALL AND TEMPERATURE DECILES VERY SOON TO FORECASTS AND SOME FURTHER CHANGES TO THESE CLIMATE OUTLOOKS TO ENHANCE THE INFORMATION FOR YOU.
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