The coming 6-week outlook takes us through the bulk of July and into August, and quite frankly gives us reasonable scope now to track how the remainder of Winter 2022 is looking and on Tuesday next week, I will have further details on that with the next Climate Update Video which will focus on that.
Plenty of you feel like you have been screwed over if you are looking at the data sets expecting higher rainfall totals than what you were expecting, with rain gauges in parts of the south and west collecting dust at the moment, but does it continue?
It is the opposite over in the east where the rain gauges are forecast to be less worked over from now through September, getting a 1/50-year event. Can we expect that to continue or is it a once off (in a year of many 1/100-year events according to authorities, which seems to be happening every year.... but anyway....)
Overall, the drier bias continues for parts of the west and along sections of the southern coastal areas with near seasonal rainfall for many areas of the southeast grading to above average along the east coast and well above average over the northeast and north which is certainly connected to the major event in the coming week. Further moisture streaming southwards over the north and northeast of the nation could also lead to follow up above average rainfall through the period. Rainfall will return to the west and along the south with the Winter westerly set to develop as the SAM tends negative through July. If the SAM refuses to tend negative, then we are likely to see drier weather persist for the SWLD of WA and into the south and possibly southeast. With the rain event over the north and the east, there is a significant risk of the average being exceeded (near 100% chance).
NEW SOUTH WALES
There has been a shift in the short and medium range to bring higher rainfall back to the east coast (as mentioned, refer back to the short and medium term forecasts to verify the longer range - the climate models did NOT see this event coming up this week) with drier weather back into the west of the state. The wet weather signal is connected generally to the short term with the easterly wind regime. That backs into the west again from next week and rainfall over the south and southeast of the nation will return and a drier westerly flow will cover NSW. Overall this pattern in the short term is quite unusual but has been seen before. The frontal weather that returns to the forecast in the short term will be struggling to pull in moisture from the Indian Ocean hence the seasonal signal for now. Forecast confidence is low.
The very wet bias is linked to the events of this week and into early next week before we see conditions dry out again. There is the chance of further rainfall developing over inland areas and along the coast throughout July as the elevated SSTs and below average pressure signals are present into July and August which means we could see further high impact Winter rain events. The weather is drier the further south and west you go through the state but even there, it is likely that rainfall will feature during a time of dry. Many areas could see 6x there monthly rainfall out of this event alone, possibly more along the coast this week. Forecast confidence is moderate.
Above average rainfall signals are running very high and that is thanks to this week of weather unfolding with widespread moisture above the average and deep troughs in the region leading to the wet bias. The rainfall along the coast also above normal thanks to the onshore winds feeding the trough over the interior. The positive SAM phase also supporting the wet two weeks on the way. The weather should return back to seasonal conditions throughout the first week of July but there could be additional rainfall developing through July and August as moisture is drawn once again from the north through to the south across the country.
A wet signal is present for northern Australia which is expected to be in response to the coming 7-10 days of rainfall and high humidity being drawn southwards into the nation. Heavy rainfall at a decile 8-10 level is forecast this week before we see the rainfall ease and seasonal weather resumes. There could be some further rainfall developing throughout the outlook period with deeper moisture developing later in July and August with the threat of early onset rainfall running high as we move into Spring. Forecast confidence is moderate.
SOUTHWEST LAND DIVISION
A drier bias is still in place for the region thanks to the persistent easterly phase for the coming 10 days or so, this is limiting the frontal weather moving through. It happens from time to time in Winter. The question will be, will the frontal weather, when it peaks through July and August in fact bring above average rainfall and allow for the deficit to be made up or do we continue with a below average filling season? I am not so sure on that but certainly a drier signal is far for inland areas for now. Above average SSTs offshore the south and southwest coast should lead to normal rainfall expectations. This carries a moderate confidence.
The wetter signal has eased from last Friday as the frontal weather from late last week is through and that delivered mainly light falls, and that looks to continue off and on through the period ahead. The frontal weather will struggle to get the moisture drawn in from the Indian Ocean for now but refer to the short and medium term guidance for more details in the weeks ahead. The pattern in the short term is a drier one for Victoria, with the easterly wind regime keeps the wet bias over NSW but that may nose into Gippsland early next week. Once the event is through, the bulk of VIC and indeed the southeast inland should see seasonal weather. The question will be, when does the Indian Ocean influence kick back in? Forecast confidence is low.
A drier bias along the west coast and nosing into the Eyre Peninsula is connected to the positive SAM phase over the course of the next 1-2 weeks, leading to drier weather. The southeast of the state may see more frequent rainfall leading to seasonal values overall and seasonal expectations are also likely over northern and central inland areas. The question that will be answered one way or another is the influence of the Indian Ocean Dipole and does that fail to return to the state or does the tap get turned on big time? Forecast confidence remains low.
%Chance of exceeding or not exceeding the median temperatures from now until the 11th of August 2022
Temperatures are forecast to remain cooler than normal for large sections of the west and warmer than normal over northern Australia. That has been a theme so far, this Winter and likely to continue. However, these areas can also see variation in the temperatures which we have experienced this week, with warmer than normal weather over the west and southwest of the country and cooler than normal weather over northern parts of the nation thanks to deep cloud cover. We could see some warmer weather developing over the east and southeast of the country with the more humid air trying to work south.
SOUTHEAST AUSTRALIA AND EASTERN INLAND
The warmer bias does exist over the western inland of QLD and into northeast SA and eastern NT, but generally elsewhere, the seasonal variation in temperatures are forecast to see most of the southeast and eastern inland of the nation at seasonal values. Does that mean no cold nights with frost, NO! Does that mean we will not have cold outbreaks? No we will see them. Does that mean we will have warmer days and settled spells - YES! That variation in the weather is thanks to the warmer than normal waters surrounding Australia and that continues to spread down the west coast throughout the period ahead. The warmer the weather gets through this period means the wetter the weather will get and earlier. So that will be a feature to watch. Forecast confidence is moderate.
The climate drivers are supportive of the warmer bias continuing throughout the period with elevated SSTs leading to more humidity and warmer days and nights. Interruption to the dry season has been an issue this season so far and continues in the short term and likely to feature again through the longer term as well. The moisture and warmer air combined, will travel further south and southeast into the nation's southern and southeastern interior with that leading to more cloud cover, so that warmer air could be offset by cloud cover in the short term. There may be further rain events developing in response to the moisture values and warmer air clashing with colder air surging northwards, and further anomalous rainfall events cannot be ruled out in this situation. Forecast confidence is moderate.
The weather is expected to be generally seasonal through the heat engine room of Australia, but I do think we see the red shading returning to the northern areas of WA after this period with a quick warm up likely, in response to the developing Indian Ocean Dipole and those warmer than normal waters running down the west and southwesst coastal areas of Australia. Higher humidity values may start to appear over the northwest of the state. With the persistent westerly and southerly flow over the southwest of the country, this will pump in cooler air over the central interior, moisture may increase via the jet stream and lead to cloudy episodes suppressing temperatures off and on throughout the period. Forecast confidence is low and dependent on the Indian Ocean Dipole developing as modelling suggests.
The southwest interior is forecast to be somewhat below average in terms of temperatures and that is thanks to the developing Indian Ocean Dipole leading to more cloud cover being present in the region with each cold front that passes through. Now while the cold fronts move through, they may not produce higher rainfall at this time, but certainly produce a lot of cloud. Cooler southwest to southerly winds are also likely to feature in response to high pressure south and west of the state leading to the onshore conditions. Forecast confidence remains low.
More coming up on this on Tuesday the 5th of July.
Additional Key Points
Touching on these points in the weeks ahead so stay connected to the page and look out for the information
I will have another update on this product on Friday morning and a video if required.
As mentioned, a broader update on the remainder of Winter 2022 coming up next Tuesday and I will have a video attached to that. Next update is the broad national Friday video is due out after 5pm EST so take a look at that.