CLIMATE - JULY OUTLOOK 2022

A deeper dive into July 2022 ahead of the August to October Outlook due tomorrow which will take a look at the broader look into late Winter and Spring 2022


ANALYSIS

When we have a developing negative Indian Ocean Dipole developing, it is not until we get into July that we see the influence ramping up across the nation and not just dammed over parts of WA, in which we have seen most of the weather events and higher rainfall events connected to the IOD located through April and May leading to flooding.


You may be seeing a drier trend developing on the modelling moving into the coming 2-4 weeks, which is so typical for this time of year under such guidance across eastern and northern Australia and should be celebrated with the catchments saturated, the longer the dry continues, the more room there is for when the rainfall returns through late Winter and into Spring because it will be a wet period after July. More on that tomorrow.


For July, the season looks generally warmer than normal over northern parts of the nation with the elevated SSTs and generally seasonal most elsewhere, but the temperatures could swing either warmer than normal or cooler than normal for large sections of the remainder of the nation in relation to the presence of cloud cover and rain spreading across the country. So that will be a conditional forecast and the forecast confidence remains low at the moment.


In terms of rainfall, the wetter weather should be over the northern and western parts of the nation spreading southeast via the jet stream and into the eastern and southeast inland. Once again, the placement of frontal weather and the relationship to the moisture feeding into these systems will dictate the rainfall spread and where it rains more consistently. Looking at previous analogues, it looks to be Central coastal WA through the western and central interior, feeding south into the Ag Areas of SA with that rainfall heavier for eastern areas and then into the southeast and inland, mainly on and west of the divide in NSW and much of VIC.


So, a good chance for most areas to at least achieve seasonal rainfall but many areas could tend above average, especially if we have one event that sits in the perfect spot for rainfall over southern and western parts of the nation. Any cut off low pressure system also offers higher rainfall chances for the country, and this will be determined by how much cold air can be cut off and then interact with the higher moisture load spreading through the country.


JULY CLIMATE OUTLOOK VIDEO 2022

RAINFALL

%Chance of exceeding or not exceeding the median rainfall for July 2022

FOOD BOWL

The signals for July are largely the same from where they were back in May and indeed March, wetter signal continues to build for the eastern inland in response to the increasing influence from the negative Indian Ocean Dipole influence. The signals for rainfall are higher of much of the southeast and eastern portions of the food bowl but marginally above normal for rainfall elsewhere. So expect some areas to sit around seasonal values at this time. However, if we see a significant amount of moisture get involved with a cut off low pressure system, that may see rainfall rates and forecasts exceed what is being shown here, but overall it would be wrong to push the signal beyond a 65% risk generally for the region.

SOUTHERN AGRICULTURAL AREAS - GOYDER’S LINE AREA

The risk of exceeding the monthly average remains marginal at about 55-60% for much of the region with then moisture profile sufficient for most areas to see a relatively good season of rainfall. Some areas about the Flinders through to the Mid North and down into the SE Districts could see heavier rainfall than what is advertised here but I am comfortable keeping the risk at about a marginal increase over the average. Watch out for the moisture running through the northern areas of the state with more widespread rainfall expected across the interior via cloud bands running through the jet stream. If this is pulled further south, then the rainfall totals will be exceeded from what is shown here, but the inverse is also true, if moisture is out of phase with frontal weather, we will see a trend to more seasonal expectations.

WESTERN AG AREAS - SWLD

The wetter than normal season is expected to continue for large areas of the west and southwest coast, with some areas already recording above average rainfall through April and May, and June so far, the rainfall rates are likely to increase. But pockets further to the east and southeast may lead to more seasonal rainfall totals for July as the moisture over the interior bypasses the region to the north and cold fronts peak over the coastal areas before weakening further eastwards. The combination of the moisture with cold fronts is the wildcard in this sequence, which will fuel higher rainfall that is shown here for the whole of the SWLD, but based upon recent weeks of observation vs the climate guidance through May and June, there may be areas that scrape to seasonal values while others see above average rainfall. So watching closely.

BROADER AREAS

NORTHERN AUSTRALIA

The moisture flirting with northern Australia and sitting offshore northern Australia right now, can be seen as a major influence through the coming dry season, and as observed, periods of higher humidity with dry season rainfall totals to be above the norm for this time of year. More organised bands of rainfall spreading from the Timor, Arafura and Coral Sea south and east will be thanks to any upper troughs passing through the central parts of the nation, which will support the moisture being drawn south into the country. This is likely from July onwards into Spring where we have to prepare for early onset rainfall.

WESTERN AND CENTRAL REGION

The western and central interior will see widespread moisture spreading in from the negative Indian Ocean Dipole influence with some areas see well above average rainfall but refer to the short and medium term forecasts for further information on specific details. The rainfall will continue through the August and into Spring as well with the risk of interior and outback flooding an issue as we move into the warmer season.

SOUTHEAST AND EASTERN REGION

Southeastern areas are generally leaning towards above average rainfall in response to the moisture profile spreading through the jet stream leading to larger cloud bands, especially if frontal weather can get involved into moisture leading to that widespread moisture being lifted into areas of organised light to moderate rainfall. Cooler season rainfall is drawn out over days rather than hours of intense rainfall, but it is more soaking and leads to the higher levels of soil moisture. The risk of flooding is expected to be quite high leading into the end of Winter and Spring 2022.

NORTHEAST AND EASTERN REGION

The eastern areas of the nation to continue leaning towards above average rainfall but as mentioned in the videos and the guidance through the interior and eastern interior, you do not need a whole lot of rainfall through this period to get above average rainfall on the go. The rainfall is expected to emanate from the northern waters more than the Indian Ocean at this time. So watching the threat for the upper troughs to move through inland Australia to pull the moisture southwards into the region.

JULY 2022

%chance of exceeding or not exceeding the median temperatures for July 2022

NORTHERN REGION

The elevated temperatures over northern Australia is in relation to the strengthening Indian Ocean Dipole and also the increased levels of humidity. Relatively seasonal temperatures further south and east for now as we see the battle of the widespread cloud cover and rainfall potential spreading through the interior and the warmer air to the north trying to push south, play out. I am thinking we will see a higher degree of variability in temperatures through areas to the south of Elliot through this period but hotter and more humid weather to areas further north. This will persist into Spring 2022.

EASTERN REGION

The east is forecast to remain at seasonal expectations, but as mentioned in the video, the risk of above average temperatures featuring through this time is quite high. The colder weather to the south of the nation will feature, but I do not think we will see temperatures as cold for as long as we have seen in recent weeks repeated through this period, but that does not mean that the risk is 0%. The overwhelming signals are for higher moisture loads, higher levels of cloud cover and rainfall spreading from the north and west across the nation which is generally of a warmer origin. So will see how the battle plays out through the region.

SOUTHEAST AND SOUTHERN

Similar conditions forecast to for the southeast where we see the battle between the warmer and more unstable moist northerly winds and the colder westerly and southwesterly winds spreading through via the cold fronts. This will mean we see conditions similar to what we see in early Spring with more variation in temperatures. Does it mean it can still be cold? Absolutely! But the long drawn out cold spell we have had through the past few weeks remains quite low at this time.

WESTERN REGION

The cooler bias over the northwest of the nation continue with the persistent cloud cover via jet stream with higher moisture loads and lower air pressure leading to widespread areas of rain. To the south and north of this region seasonal temperatures are expected for now with no strong signal for colder weather at this time. But if the rainfall and cloud cover is more extensive and the SAM is more negative, then the cooler bias may spread right throughout the region so that will be an issue covered off more in the short and medium term forecasts moving forward in the weeks ahead.

Key Points

Refer to video for further context

Areas to Watch

Refer to video for further context

DATA - Refer to the video for more context behind my forecasts by also the data sets underpinning this forecast and where the skill scores lay with each set.


Euro Rainfall Outlook July

Refer to the climate video for more context between all the data sets.

CANSIPS Rainfall Outlook July

Refer to the climate video for more context between all the data sets.

CFS Rainfall Outlook July

Refer to the climate video for more context between all the data sets.

Euro Temperature Outlook July

Refer to the climate video for more context between all the data sets.

CANSIPS Temperature Outlook July

Refer to the climate video for more context between all the data sets.

CFS Temperature Outlook July

Refer to the climate video for more context between all the data sets.

As mentioned, tomorrow I will have the AUGUST TO OCTOBER OUTLOOK for 2022. Enjoy your day!