Australian Weather

22 Jul 2024, 3:17AM UTC

There has been a major shift in the wind pattern over southern Australia, with another great wind power week on the cards.   During autumn and the beginning of winter, the National Electricity Market (NEM) saw a wind drought in response to abnormally high pressure, forcing cold fronts and the associated wind south of Australia.  There has been a shift in this pattern in recent weeks, with plentiful cold fronts and low-pressure systems drifting across southern Australia. This has been influenced by a long wave trough impacting Australia in recent weeks.  Last week, the NEM saw its windiest week in more than a year, contributing 897 GWh/week to the grid.   Image: Wind weekly contribution to generation (GWh/week) for the last year leading up to Sunday, July 21, 2024. Source: OpenNEM  The cold front that impacted southern Australia late last week brought widespread damaging winds to several states and territories.  This week will be windy again as several cold fronts sweep across the south of the continent. The image below shows Weatherzone’s NEM wind farm output for the next week.  Image: Weatherzone’s National Electricity Market wind farm output for the next 7 days in MWH.  You can see the windiest days this week are expected to be Tuesday and Wednesday, as a cold front moves across southeastern Australia. A low pressure system will then move across the Bight later this week, bringing another burst of strong winds to the region.  Image: Instantaneous wind gust forecast for 1pm AEST on Wednesday, July 24, according to ECMWF.  Winds are likely to reach damaging strength over parts of southeastern Australia during this week. Tas could see damaging winds impacting the state each day between Tuesday and Saturday.  Meanwhile parts of SA, Vic, NSW and the ACT should see damaging winds on Wednesday and Thursday. These winds have the potential to cause cut outs, where wind turbines are turned off in strong winds to prevent damage. Most wind farms turn off the turbines if the wind speed reaches the ‘cut off’ wind speed of 90km/h (25m/s), which means that the wind power is not being harnessed. During these periods of intense winds, wind power capacities will be reduced if the turbines remain turned off.     This westerly wind pattern will also bring a warm week to parts of southeastern Australia and increased rainfall over parts of southwestern WA, Tas and southern Vic and the western plains in NSW.   Image: Accumulated rain forecast for the week leading up to 10am Monday, July 29, according to ECMWF  The increased cloud associated with the frontal activity will reduce solar output in these areas.  Looking further ahead, we should continue to see increased wind and frontal activity across southern Australia during late July and August in response to the Sudden Stratospheric Warming event.   

05 Jul 2024, 2:14AM UTC

After a lull in the winds this week, wind power is set to pick up from rock bottom as a rare easterly wind surge impacts Qld, NSW and SA.  Wind power has been slack this week across the National Electricity Market (NEM) in response to a stubborn high-pressure system which has parked itself over the Bight.  Image: Mean Sea Level Pressure (MSLP) at 10am on Friday, July 5  This high will continue to sit over the Bight and Tas, until it finally moves east into the Tasman Sea on Monday, July 8.  The image below shows that we saw low wind power in the order of 30 to 60 GWh/day in response to this high earlier this week, but wind has picked up slightly to 100 GWh/day on Thursday, July 4.  Image: Wind contribution to generation (GW) during the last 30 days leading up to Thursday, July 4. Source: OpenNEM  Usually with high pressure sitting over the Bight, wind power should continue to be low into next week.  However, the images below show a rare easterly wind surge elevating winds slightly across parts of Qld, NSW and SA from Friday and possibly Vic on Monday.  Images: Instantaneous wind gust forecast between Friday, July 5 and Thursday, July 11  While it is common for easterly winds to move over Australia, it is the strength of the wind that is unusual. The strongest winds over southern Australia, typically originate from the north or south, while for the east coast, westerly winds are typically the strongest.   These winds are normally associated with cold fronts sweeping over the country. This weekend we will see easterly winds strengthen as they feed into a cut of low over SA cradled by a high-pressure system in the Bight.  The easterly wind surge will not match the strength of winds associated with cold fronts, so wind power will remain low to medium across Qld, NSW. In South Australia, wind speeds over the weekend should be strong, especially about the Flinders Ranges and western slopes from Saturday morning. As of 2:50pm Friday, there is a damaging wind warning out for these areas. Wind farms near Port Augusta could see winds reaching 90km/h from Saturday morning, with the potential for cut outs. The image below shows that the wind farm output across the NEM should increase ever so slightly in the coming days, compared to the very low winds we saw earlier this week.  The image below shows that the wind farm output across the NEM should increase ever so slightly in the coming days, compared to the very low winds we saw earlier this week.    Image: Weatherzone’s Opticast Wind Farm Output for the NEM from Friday, July 5 to Friday, July 12.  The stronger easterly winds in these states, will also be accompanied by a thick northeasterly cloudband stretching from the Coral Sea down to SA. You can see in the image below that it has already begun thickening up and producing rainfall in these areas.   Image: Himawari-9 satellite image at 11:50am AEST on Friday, July 5  This cloudband is likely to reduce solar output in these states between Friday and early next week.  So, when is decent wind power coming?  You can see in the image above wind power is forecast to increase above 150 GWh day later next week in the NEM, with strong cold front finally able to make its way across southern Australia.  To find out more, please visit our contact page or email us at business@weatherzone.com.au.