July 2023 Outlook SA
July 2023 outlook SA
*Forecast prepared between July 1st-July 4th 2023
Review:
G’Day everyone, July is now here as we mark the pivot in 2023 which is a crucial time for many however so far this growing season, the weather has been for the most part fairly kind, especially in June which went every bit to expectations and in some areas like the NW Pastoral, exceeded that. I won’t recap all the events as the first half can be found in the June update however there was a significant event with a NW cloudband and strong upper trough from June 21st-23rd where especially on the 22nd, conditions were very wet indeed through the afternoon and evening with widespread areas of rain turning into showers, heavy at times with isolated thunderstorms with a focus around the Adelaide area. Flooding occurred through the Onkaparinga and Sturt River catchments and associated crossings with a number of them going well under. One gauge at Coromandel Valley went to major flood with a very rapid wise and a number also reached minor to moderate levels. The highest 24hr gauging to 9am on 23rd from this was 96mm at Woodhouse in the Adelaide Hills with numerous 70-90mm totals in surrounding areas also.
The next main event was focused to the south with the Southern Coastline copping a sustained barrage of cold air that lasted 2-3 days in an unstable NW to W airstream. Myself in the Southern suburbs of Adelaide only managed 3mm for that period however Kangaroo Island and the Southern Fleurieu received falls up to 120mm with localised flooding of rivers and associated tributaries. The heavy influence of a negative leg of the Southern Annular Mode (SAM) really came to the fore here and it shouldn’t be forgotten that parts of the Lower SE also received near record rainfall for June with the Mt Gambier gauge recording it’s wettest June on record with 165.2mm (for that location). Wetter June’s at the old post office site had been recorded but being a different physical location, it can be tricky to compare.
Now a quick look at the rainfall charts for June and how the forecast performed to the final outcomes:
Now the official outlook for June was as follows:
"So, to the all-important June outlook and as you may imagine, it doesn’t look all that bad at all and we will see some areas get good rainfall in an out of the box month. Generally average to slightly above average rainfall for the Central parts of the state including the Lower and Upper North, increasing to above average to well above average for the eastern portions of the NE Pastoral, Riverland and Mallee. Yorke Peninsula will be around average, but I think Eyre Peninsula may come just short with slightly below average, especially in the north at this stage. The NW Pastoral is likely to be mixed with above and below average rainfall, lower towards the WA border. Kangaroo Island and the SE Districts should be close to average, but perhaps above average for the Upper SE and towards the VIC border. Western VIC will see well above average rainfall as will much of Victoria in a very wet June and some areas may even get close to 1991 levels which was very wet."
Overall, a fairly close estimation of the trend of the rainfall location wise, however slightly off with regards to the drier areas and wettest areas. The drier far west portions of the state towards the WA border did occur though the drier parts of EP were confined to the northern portion only with below average rainfall there. The Lower Eyre Peninsula certainly did quite well with above average falls and that trend repeated over the Yorke Pen with average to well above near the foot. The Central Districts such as the Lower and Upper North were very close to average but generally slightly above. East of the ranges we saw generally above average falls tending to very much above average over the Upper and Lower SE. The Pastorals were wetter towards the QLD/NSW border and drier towards WA, but a large swath of the interior was well above average thanks to a large NW Cloudband.
Meteorological Discussion:
So, onto July we go! And this is a month that I’ve been pigeon holing for quite sometime to be drier than the average for the most part and broadly speaking that has not changed much although as mentioned, I do expect if you are far south enough (Goyder's Line roughly) then it shouldn’t be as bad as of this current time, I feel that is still close enough to the mark as we should experience a fairly zonal month as opposed to partially meridional June were we had lots of warm air coming down from the north met by colder air from the south – July will see a more consistent westerly belt whistling away below the mainland with vigourous fronts at times, but chiefly affecting more southern locations and less influence further north. Frost risk will also increase inland away from the windy westerly belt and more so later in the month I feel as the SAM tries to push more positive but for the meantime, it looks quite neutral. More on that driver in the climate section.
The current situation shows a large cloudband covering the eastern states and as well as the eastern half of SA. Area of rain are being generated from this cloudband with locally heavy falls across the interior of QLD with steady soaking rainfall to area that actually haven't had a good drop for quite some time now. An upper-level trough that was pinched off from the lingering longwave that dominated our weather through June is responsible. Despite the thick middle and high-level cloud across SA, as well as widespread lower cloud further west, most of the state remains rain free due to the distance from the triggering mechanism and is essentially just ‘exhaust’ cloud being drawn south by N-S upper-level winds. At best we will only see some light patchy rain across the eastern border districts east of the ranges with maximum totals around 2-3mm. ***EDIT*** just thought I’d add that some 5-6mm totals were recorded on the far eastern border from this which would have been most welcome!
Of more interest is the series of cold fronts wrapping around a deep low located over the waters south of the Bight. These fronts will be responsible for a burst of wet and windy weather across chiefly the south of the state later this week and into the weekend and I’d expect a Sheep Graziers Alert to be issued for this period as conditions will be very cold for livestock with the persistent wind and showers.
The first front is current crossing the SW corner of WA and will weaken as it moves eastwards through the Bight during the 4th and at best, we will see N to NW winds freshen as isobars get squeezed. The front with associated isolated showers and thunderstorms will then slide SE without too much impact on the coast at all with perhaps just some isolated showers clipping the coasts of Lower Eyre Peninsula and Kangaroo Island on the 5th.
Behind this front will see a very large area of cold and unstable air associated with an upper level trough barrel up from the deep SW and the first port of call will be the SW capes of WA as well as the southern coastline out to about Esperance or so which are going to see a sustained barrage of squally showers, with heavy falls as well as isolated cold air thunderstorms and small hail. This cold air will allow some frontogenesis to occur with a cold front developing on the leading edge as it stands up in the Bight later on the 5th and during the 6th. With enough warmth and lift ahead of this front on the 6th, a weak pre-frontal surface trough will develop across the Central and Eastern Districts with some scattered showers and isolated thunderstorms. NW winds will then freshen and become strong at times ahead of the cold front and upper trough advancing from the west bringing further scattered showers and isolated thunderstorms, with some locally heavy cells about due to the instability. Small to moderate hail is likely in stronger cores in the 1-2cm range during the afternoon of the 6th as instability and solar heating is at a maximum. I should note that we will see a similar setup with the jet streak located inland over the interior like previous strong systems however this one is considerably weaker overall compared to those in June.
Now behind the cold front winds will still be fresh to strong in a deep and established westerly airstream with cool to cold and blustery conditions with stream showers well scattered across the agricultural areas, however this activity will become a lot more isolated anywhere north of about Cummins to Adelaide to Keith by the mid-evening with the coldest and most unstable air aloft contracting out of the state.
However, the moderation will be short-lived before a shortwave trough moves in rapidly from the SW from the mid-morning on Friday the 7th. Winds will swing NW and strengthen ahead of the trough before turning westerly behind. Showers will increase and become frequent with this trough during the day before easing during the early evening.
Yet another cold front then will move in more quickly in from the WSW during the late evening and more so early hours of Sat 8th. Winds will again swing back NW ahead of this front and this time will likely become strong to even gale force about exposed coasts with likely severe wind warnings for damaging winds. Showers will increase with the approach of the cold front with a narrow squall line of isolated thunderstorms, chiefly on the southern half of it likely as it advances in before it weakens upon crossing. Showers may be heavy at times about the ranges and southern coastal locations including the Lower SE. Behind the front will see a pool of cold air extend across the south, primarily over the Lower SE District with cold and squally W to SW winds, possibly damaging at times about exposed coasts still. Showers and scattered small hail showers are also likely here. Swells and large surf are likely due to the ‘double up’ effect of these systems passing over an already active sea state so take heed for those that work near the coastline. This front whilst, fast moving lacks a lot of SW-NE punch so the penetration factor inland will be somewhat limited, I think. I should also note that there will be a significantly enhanced rain shadow with the stronger westerly flow with an abrupt dry lee wave off the back of the ranges, with mostly only the Southern Mallee seeing much influence from the fronts. The best chance of precipitation to the east of the ranges will be from the pre-frontal trough initially.
Beyond this it gets a little tricky but there is likely to be another couple of weaker fronts pass mostly below or clip the state on the 10th and 12th with a stronger front due around the 14th-15th where shower activity is likely to increase again. The gradual influence of high pressure over the mainland should slowly increase from Mid-month after this system as the Hadley cell finally gets a chance to expand and re-align in the Australian longitude which will primarily be from the longwave trough moving eastwards. An active westerly belt should remain however across waters to the south of the mainland with frequent fronts. Large swells will continue to impact the coastline from time to time, with plenty of surf available (subject to winds for cleanliness) for those seeking to find some good waves. The greatest risk for frost at this stage looks to be broken into two sections but from the 10th onwards inland/Pastoral especially we start to see a slight risk. This may push to moderate across prone areas through the Upper North and Riverland if the high pressure is slightly further south. A greater risk looks likely to develop from about the 16th onwards after a stronger front/cold air if the
high pressure does intensify over the state and that would be in the moderate to heavy category, especially over the Upper North and Riverland Districts. If a severe/heavy frost risk looks more locked in, I will issue a special update for that because so far this season has been most kind with only very slight frosts at times and again well inland.
So, to the all-important July outlook and broadly speaking we will see a drier month than June, especially inland. Below average rainfall across the NW tending closer to average for the eastern part of the NE Pastoral. There will be a grading from below average rainfall across northern agricultural areas to near average across the southern agricultural areas. The most prone to below average rainfall include the Northern Eyre Peninsula and Upper North as well as the Riverland. The Mallee will be closer to average but probably still slightly below. Most other districts should come around their average. The greatest chances of above average falls will be about Kangaroo Island and the Lower SE and potentially the tip and western portions of Eyre Peninsula and this is primarily due to the expected zonal pattern.
Climate Drivers
The Pacific Ocean is ever so slowly nudging toward and El Nino which has officially been declared by NOAA but not by the BoM due to different criteria required for such a call. Eventually it will satisfy the BoM criteria as well – mostly likely by August at a guess. But what is happening in the meantime can be visualised better in Figure 4.
Now looking at Figure 4 we can see that the warm spike from the far Eastern Pacific has slowly increased and begun to encroach to the west along the equator. The Nino 3.4 region which is what El Nino is classified through still is only warming slowly but this will change in the coming months. The main things halting the El Nino progression is the colder water from the North American PDO off the west coast of the USA/Canada and also the warmer water persisting in the Coral and east of PNG. These both should temper whilst Nini 3.4 warms in the next 2 months but overall, the strength of this El Nino will only get to moderate. The sub-surface still has +6C anomalies to surface in the east so that is to be noted as well with also +3C anomalies to surface in the Nino 3.4 region. Trade winds are still at least average but have been reduced by some Westerly Wind Bursts in recent months.
The Indian is locked in a to and fro with regards to which direction it wants to take. Colder water is persisting off the NW coast of WA which does mean the next step isn’t far away. Whilst a weak positive IOD is beginning to show those early signs of formation, recent persistent warmth across the entire basin has left the entire formation process in a holding pattern. Strong high pressure through the mainland of Australia in July should then finally allow trades to blow back west off Sumatra and thus upwelling some colder water. Many forecasts have this being a strong positive IOD but again I think moderate at best and peaking in September. The main take home from both the Pacific and Indian is a lack of ocean to atmosphere connection and resultant feedback. As a result I feel we still will have a drying trend but with a slight wobble back in August with more jetstream instability mixed with increasing frost. September then is likely to see those impacts with a greater intensity with late frost and drier weather more likely.
The SAM has been a big driver on our weather through June with a nice negative burst from a stubborn and blocked longwave trough in our longitude. The index is now back in neutral territory and should for the most part stay there till mid-month or later July when we should see more positive values occur thanks to more high pressure over the mainland.
As for the MJO though, it is safe to say there is almost no major influence on our weather from that at this current point in time with only weak to moderate westerly wind bursts pushing around the globe. These at least will help combat the trade winds in the Pacific as mentioned earlier to help set up the El Nino but we still need an ocean to atmosphere connection. Even once that occurs, there is a lag before actual on ground impacts on our weather.
Districts:
Eyre Peninsula
Weakening cold front sliding below the mainland very early on 5th with isolated showers. Freshening NW winds with showers increasing ahead of and on a cold front due later on 5th and early on the 6th with isolated thunderstorms. Localised heavy falls in heavier cells with small hail also. Colder air to pass over during day on 6th with a continuation of showers and isolated thunderstorms with small hail, chiefly in the afternoon and also about the exposed western and southern coasts. Strong to gale force westerly winds extending across the Peninsula in the wake of the front, especially about the Western Coasts. Activity much more isolated with northern and NE’ern extent across the Peninsula except for during the afternoon where solar heating will allow a brief window for these areas to receive scattered activity. Showers becoming isolated during the evening. Follow up trough due on 7th with increasing showers. Isolated thunderstorms again over Lower Eyre Peninsula chiefly. Activity becoming isolated once more later on 7th. Strengthening NW winds reaching gale force about exposed coasts ahead of a cold front due early 8th with a band of showers. Colder, squally W to SW winds on and behind the front with scattered showers quickly becoming isolated later. Large swells and hazardous surf across exposed coastlines. Weak front brushing coast about 10th may trigger a brief isolated shower or two. Another cold front due around 14th to 15th with potentially a band of showers and colder air. Slight frost risk inland from 10th to 13th. Another period of greater risk potentially from 16th. Rainfall for period 10-20mm generally, increasing to 20-30mm about the Lower Eyre Peninsula. Isolated localised totals to 40mm about Southern/Western coasts. Totals decreasing markedly toward NE EP down to around 2-5mm.
Upper North
Weakening cold front sliding below the mainland very early on 5th but remaining dry. Freshening NW winds with scattered showers and isolated thunderstorms developing along a pre-frontal trough very late 5th or early 6th. A brief clearance before a cold front moves through during the afternoon of the 6th with scattered showers and isolated thunderstorms, chiefly on and in wake of front in colder air. Chance of small hail in stronger cells. Strong to gale force westerly winds extending across the district in the wake of the front, especially about elevated terrain/exposed peaks. Shower activity more isolated over the Flinders before becoming isolated elsewhere by the evening. Follow up trough due on 7th with isolated showers, chiefly in the south before clearing later. Strengthening NW winds reaching gale force about exposed coasts and higher peaks ahead of a cold front due after dawn on 8th with a band of showers, again more isolated in the north towards the Flinders. Colder, squally W to SW winds on and behind the front with isolated showers, mostly clearing by the evening apart from onshore flow into higher terrain. Weak front brushing coast about 10th may trigger a brief isolated shower in the south. Another cold front due around 14th to 15th with potentially a band of showers and colder air. Frost risk beginning from 10-14th at slight to moderate. Potential for greater frost risk from 16th. Rainfall for period 8-15mm generally. Isolated falls to 20-25mm about higher peaks/elevated terrain. Totals decreasing off backs of ranges down to only 3-8mm.
Lower North
Weakening cold front sliding below the mainland very early on 5th but remaining dry. Freshening NW winds with scattered showers and isolated thunderstorms developing along a pre-frontal trough very late 5th or early 6th. A brief clearance before a cold front moves through during the afternoon of the 6th with scattered showers and isolated thunderstorms, chiefly on and in wake of front in colder air. Chance of small hail in stronger cells. Strong to gale force westerly winds extending across the district in the wake of the front, especially about elevated terrain/exposed peaks. Shower activity becoming isolated by the evening. Follow up trough due on 7th with scattered showers, isolated in the north before clearing later. Strengthening NW winds reaching gale force about exposed coasts and higher peaks ahead of a cold front due after dawn on 8th with a band of showers. Colder, squally W to SW winds on and behind the front with isolated to scattered showers, mostly clearing by the evening apart from onshore flow into higher terrain. Weak front brushing coast about 10th may trigger a brief isolated shower or two. Another cold front due around 14th to 15th with potentially a band of showers and colder air. Frost risk beginning from 10-14th at slight to moderate. Potential for greater frost risk from 16th. Rainfall for period 10-20mm generally. Isolated falls to 20-30mm about higher peaks/elevated terrain. Totals decreasing off backs of ranges down to only 3-10mm.
Yorke Peninsula
Weakening cold front sliding below the mainland very early on 5th with isolated showers near the foot. Freshening NW winds with showers increasing ahead of and on a cold front due later on 5th and early on the 6th with isolated thunderstorms. Localised heavy falls in heavier cells with small hail also. Colder air to pass over during day on 6th with a continuation of showers and isolated thunderstorms with small hail, chiefly in the afternoon. Strong to gale force westerly winds extending across the Peninsula in the wake of the front, especially about the foot. Showers becoming isolated during the evening. Follow up trough due on 7th with increasing showers. Isolated thunderstorms again over the foot. Activity becoming isolated once more later on 7th. Strengthening NW winds reaching gale force about exposed coasts ahead of a cold front due early 8th with a band of showers. Colder, squally W to SW winds on and behind the front with scattered showers quickly becoming isolated later. Large swells and hazardous surf across exposed coastlines down near the foot. Weak front brushing coast about 10th may trigger a brief isolated shower or two. Another cold front due around 14th to 15th with potentially a band of showers and colder air Slight frost risk in the north from 10th to 13th. Another period of greater risk potentially from 16th. Rainfall for period 10-20mm generally, increasing to 15-25mm about the foot. Isolated localised totals to 30mm again about the foot. Totals decreasing towards the eastern coastline but generally still closer to 8-10mm.
Kangaroo Island
Weakening cold front sliding below the mainland very early on 5th with isolated showers. Freshening NW winds with showers increasing ahead of and on a cold front due later on 5th and early on the 6th with isolated thunderstorms. Localised heavy falls in heavier cells with small hail also. Colder air to pass over during day on 6th with a continuation of showers and isolated thunderstorms with small hail. Strong to gale force westerly winds in the wake of the front. Showers becoming isolated during the evening. Follow up trough due on 7th with increasing showers from as early as before dawn before frequent showers occur from around late morning with isolated thunderstorms. Showers becoming less frequent but still scattered later on 7th. Strengthening NW winds reaching gale force about exposed coasts ahead of a cold front due early 8th with a band of showers and isolated thunderstorms. Damaging gusts likely. Colder, squally W to SW winds on and behind the front with scattered showers quickly becoming isolated later. Large swells and hazardous surf developing, especially about exposed western and southern coasts. Weak front brushing coast about 10th may trigger some isolated showers. Another cold front due around 14th to 15th with potentially a band of showers and colder air. Rainfall for period 30-40mm generally, increasing to 50-70mm towards the western end. Isolated heavier totals with possible flooding again near the western end to 80mm. Totals decreasing towards the eastern coastline down to around 20-30mm.
Adelaide Plains
Weakening cold front sliding below the mainland very early on 5th but generally remaining dry. Freshening NW winds ahead of a pre-frontal trough with scattered showers and isolated thunderstorms in early hours of 6th. A brief clearance before showers then increase ahead of and on a cold front due in early of 6th with isolated thunderstorms. Localised heavy falls in heavier cells with small hail also. Colder air to pass over during day on 6th with a continuation of showers and isolated thunderstorms with small hail, chiefly in the afternoon. Strong to gale force westerly winds extending throughout in the wake of the front, especially near the coast. Showers becoming isolated during the evening. Follow up trough due on 7th with increasing showers and isolated thunderstorms, more frequent south of about Seaford. Activity becoming isolated once more later on 7th. Strengthening NW winds reaching gale force about exposed coasts ahead of a cold front due early 8th with a band of showers. Colder, squally W to SW winds on and behind the front with scattered showers quickly becoming isolated later. Stormy surf across the metro and Mid-Coasts. Weak front brushing coast about 10th may trigger a brief isolated shower or two. Another cold front due around 14th to 15th with potentially a band of showers and colder air. Slight frost risk about outer plains from 10th to 13th. Another period of greater risk potentially from 16th. Rainfall for period 20-30mm generally, increasing to 30-40mm about the foothills. Totals decreasing towards the gulf coast and outer plains down to around 15-20mm.
Mt.Lofty Ranges
Weakening cold front sliding below the mainland very early on 5th but only isolated showers about the tip of the Fleurieu. Freshening NW winds ahead of a pre-frontal trough with scattered showers and isolated thunderstorms in early hours of 6th. A brief clearance towards the northern ranges before showers then increase ahead of and on a cold front due in early of 6th with isolated thunderstorms. Localised heavy falls in heavier cells with small hail also as well as about higher peaks. Colder air to pass over during day on 6th with a continuation of showers and isolated thunderstorms with small hail, chiefly in the afternoon. Strong to gale force westerly winds extending throughout in the wake of the front, especially near higher peaks and the Fleurieu coastline. Showers becoming isolated during the evening in the north. Follow up trough due on 7th with increasing showers and isolated thunderstorms, more frequent south of about Kuitpo. Local heavy falls. Activity becoming isolated once more later on 7th. Strengthening NW winds reaching gale force about exposed coasts and higher peaks ahead of a cold front due early 8th with a band of showers. Colder, squally W to SW winds on and behind the front with scattered showers quickly becoming isolated later. Large swells and hazardous surf about the Fleurieu coastline. Weak front brushing coast about 10th may trigger a brief isolated shower or two. Another cold front due around 14th to 15th with potentially a band of showers and colder air. Slight frost risk towards the Barossa from 10th to 13th. Another period of greater risk potentially from 16th. Rainfall for period 30-50mm generally, increasing to 50-70mm south of about Mt.Lofty. Localised heavier totals up to 90mm about known wet spots. Localised stream and river rises with each system, some likely to minor flood levels. Totals decreasing down to around 15-25mm off the backs of the ranges with strong lee shadowing.
Riverland/Mallee
Weakening cold front sliding below the mainland very early on 5th but remaining dry. Freshening NW winds with scattered showers and isolated thunderstorms developing along a pre-frontal trough very late 5th or more likely early 6th. A brief clearance before a cold front moves through during the afternoon of the 6th with isolated showers and thunderstorms, chiefly on and in wake of front in colder air. Chance of small hail in stronger cells. Fresh to strong westerly winds extending across the district in the wake of the front. Shower activity more isolated over the Riverland with the colder air. Follow up trough due on 7th with isolated showers, but scattered over the Mallee in the SW before clearing later. Strengthening NW winds reaching gale force towards the south of the Mallee ahead of a cold front due before dawn on 8th with a band of showers, again more isolated in the north towards the Riverland as the front weakens. Colder, squally W to SW winds on and behind the front with isolated showers, mostly clearing by the evening. Weak front brushing coast about 10th may trigger some isolated shower activity in the south of the Mallee. Another cold front due around 14th to 15th with potentially a band of showers and colder air. Frost risk beginning from 10-14th at slight to moderate. Potential for greater frost risk from 16th. Rainfall for period 5-10mm generally. Isolated falls to 12-15mm about the far south of the Mallee. Totals decreasing towards the northern Riverland down to 3-5mm.
Upper SE
Weakening cold front sliding below the mainland on 5th but only isolated coastal showers occurring. Freshening NW winds ahead of a pre-frontal trough with scattered showers and isolated thunderstorms in early hours of the 6th, chiefly towards the N and NE of the district. A brief clearance before showers then increase ahead of and on a cold front due in early afternoon of 6th with isolated thunderstorms. Localised heavy falls in heavier cells with small hail also. Colder air to pass over during day on 6th with a continuation of showers and isolated thunderstorms with small hail, chiefly in the afternoon. Strong to gale force westerly winds extending throughout in the wake of the front, especially near the Coorong coast. Showers becoming isolated during the evening. Follow up trough due on 7th with increasing showers and isolated thunderstorms, more frequent near the Coorong coastline once again and also towards the Lower SE border. Activity becoming isolated once more later on 7th temporarily. Strengthening NW winds reaching gale force about exposed coasts ahead of a cold front due early 8th with a band of showers with isolated thunderstorms likely in the south. Colder, squally W to SW winds on and behind the front with scattered showers quickly becoming isolated later. Large surf about the Coorong coastline. Weak front brushing coast about 10th may trigger a brief isolated shower or two. Another cold front due around 14th to 15th with potentially a band of showers and colder air. Slight frost risk about outer plains from 10th to 13th. Another period of greater risk potentially from 16th. Rainfall for period 20-30mm generally, increasing to 30-40mm about the LSE border and southern Coorong coastline. Totals decreasing towards the Mallee border down to around 12-20mm.
Lower SE
Weakening cold front sliding below the mainland on 5th but only isolated coastal showers occurring. Freshening NW winds ahead of a pre-frontal trough with scattered showers and isolated thunderstorms in early hours of the 6th, chiefly towards the N and NE of the district. A brief clearance before showers then increase ahead of and on a cold front due in early afternoon of 6th with isolated thunderstorms. Localised heavy falls in heavier cells with small hail also. Colder air to pass over during day on 6th with a continuation of showers and isolated thunderstorms with small hail, chiefly in the afternoon. Strong to gale force westerly winds extending throughout in the wake of the front, especially near the coast. Showers becoming isolated during the late evening. Follow up trough due on 7th with increasing showers and isolated thunderstorms, throughout the day, tending to rain at times with local heavy falls likely. Strengthening NW winds reaching gale force about exposed coasts ahead of a cold front due early 8th with frequent showers, areas of rain, heavy at times as well as some isolated thunderstorms along a linear squall line. Colder, squally W to SW winds on and behind the front with scattered showers, small hail and generally very unpleasant conditions. Damaging winds likely, especially about exposed coasts. Showers becoming isolated by early 9th however shower activity will linger in a moist onshore westerly flow keeping conditions damp. Large swells and hazardous surf about the coastline. Weak front brushing coast about 10th may trigger a band of light showers. Another cold front due around 14th to 15th with potentially a larger band of showers and colder air. Slight frost risk about outer plains from 10th to 13th. Another period of greater risk potentially from 16th. Rainfall for period 40-50mm generally with localised heavier falls up to 70mm near the coast. Totals decreasing towards the NE corner but still closer to 25-30mm.
Western VIC
Weakening cold front sliding below the mainland on 5th but remaining dry. Freshening NW winds ahead of a pre-frontal trough with scattered showers and isolated thunderstorms from mid-morning of the 6th. A brief clearance before showers then increase in a line on a cold front due in early to mid-afternoon of 6th with isolated thunderstorms. Localised heavy falls in heavier cells with small hail also. Fresh to strong westerly winds behind the front. Showers becoming isolated during the evening. Follow up trough due on 7th with increasing showers and isolated thunderstorms, chiefly about the SW District initially but then extending to the Wimmera with shower activity generally being more isolated across the Mallee. Strengthening NW winds reaching gale force about exposed coasts ahead of a cold front due early 8th with a band of showers with isolated thunderstorms likely over the SW District. Showers will also tend to a band of rain down here. Showers in the frontal band weakening on crossing the Mallee District during the day. Colder, squally W to SW winds on and
behind the front with scattered showers and small hail quickly becoming isolated later and becoming confined to the southern coastline. Large swells and hazardous surf about the coastline. Weak front brushing coast about 10th may trigger a brief isolated shower or two. Another cold front due around 15th with potentially a band of showers and colder air. Slight frost risk inland from 10th to 13th. Another period of greater risk potentially from 16th. Rainfall for period 25-35mm generally about the SW District increasing to 35-45mm about the coast and also elevated terrains in the Grampians. Totals decreasing towards the northern Wimmera in the order of 15-25mm and further down to 5-15mm across the Mallee.
Final Notes
- El Nino and Positive IOD still in formation with no ocean to atmosphere connection to date – expected by mid-August with lag to occur till September where it looks to be a drier month
- Mixed fronts and dry spells till then, drier to the north and enough rainfall from fronts further south however the overall trend is getting drier with an increasing frost risk, chiefly late
- August likely wetter than September and July at this stage
- Strong fronts and very windy conditions as a particularly mobile westerly belt slings fast moving systems across the agricultural areas
- Spring overall looking like below average rainfall
- Outlook into 2024 dependent on magnitude of El Nino, but I expect a return to slightly wetter conditions overall should the remnant heat in oceans be utilised
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Happy Farming and Cheers from The Weatherman
*Note – For interest only, all thoughts are of The Weatherman and may not be reproduced without my consent.
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