Troughs & a front are generating brisk winds & showers in northern WA, the interior, southern SA, VIC & NSW, as well as a few storms in northern WA. Another trough is causing patchy showers in WA's south. Brisk southerly winds on the QLD coast are bringing just the odd shower.
Weather in Business
Today, 4:23AM UTC
More rain as another northwest cloudband crosses Australia
This week’s weather will be a perfect example of how a negative Indian Ocean Dipole (IOD) affects Australia, with a thick northwest cloudband causing widespread rain and flooding. The satellite image below shows a northwest cloudband extending over Australia on Wednesday, August 10. This northwest cloudband is forming as upper-level winds transport moisture-laden air from the tropical Indian Ocean across the Australian continent. This stream of tropical moisture is linking up with a mid-latitude low pressure system and associated cold air mass to creating a large and thick band of cloud. This type of weather pattern is common during a negative IOD and this is the second such cloudband that has affected Australia since the negative IOD was declared last week. After soaking parts of WA earlier this week, this cloudband will drift further east over the next few days and produce widespread cloud and rain over parts of every other state and territory in Australia. The maps below show where one forecast model predicts rain on each of the next four days. Image: Forecast daily rainfall during the rest of this week, between Thursday and Sunday. This system is likely to produce around 10 to 30 mm of rain over a broad area of eastern and southeastern Australia between Thursday and Sunday, extending from central QLD down to TAS and SA. Showers are likely to continue over parts of TAS, VIC and NSW early next week as a low pressure system lingers above the western Tasman Sea. Another cold front should also bring a burst of rain in WA from around Tuesday next week. Over the next seven days, rain that is heavy enough cause flooding could affect several states and territories. This includes parts of the Murray Darling Basin, as well as areas in NSW, VIC and TAS that were affected by flooding last week. Image: Forecast accumulated rain during the next seven days (Wednesday to Tuesday) accoring to the ECMWF-HRES model. Flood watches and warnings are likely to be issued in the coming days, so be sure to check the latest warnings in your area.
Today, 1:26AM UTC
Coldest day in years, frost on the way in WA
Parts of southwestern Australia just shivered through their coldest day in more than a decade as a polar air mass hit WA. The sequence of satellite images below shows a cold front and trailing polar air mass passing over the southwest of WA during the last two days. Video: Composite infrared/visible satellite images over the past 48 hours, showing cold air spreading over southwestern Australia on Monday and Tuesday. On Tuesday, Perth only reached a maximum temperature of 12.4ºC, which is about 7ºC below average for this time of year. This made Tuesday the city’s coldest day in two years and its fourth coldest day this century. Nearby, Bickley’s top temperature of 9.4ºC on Tuesday was its coldest day since 2005 and its coldest August day in records dating back to 1994. These abnormally low temperatures were made possible by a cold air mass combined with frequent rain and cloud cover, with Perth collecting close to 40mm of rain during the 48 hours to 9am on Wednesday. In the far south of WA, some of Tuesday’s precipitation even fell as snow on the Stirling Range. Daytime temperatures will gradually warm up over the next few days, with Perth forecast to reach about 17ºC on Wednesday and up to 21ºC by Friday. However, clear skies and lighter winds will cause very cold overnight temperatures across southern WA over the next few nights, with frost likely over the state's southern inland. Image: Forecast minimum temperatures on Thursday morning according to the ECMWF-HRES model.
09 Aug 2022, 10:48PM UTC
No bluffing, snow just fell in WA
Snow has fallen on Bluff Knoll in the Stirling Range in SW Western Australia, with locals flocking to see the flakes. Image: It's usually just the very summit of the mountain that sees settled snow. Source: Jodie Jones. We wrote yesterday about the severe chill headed for the southwestern corner of WA, noting that a particularly icy pool of air was tracking northwards from the Southern Ocean. For example, Perth had its coldest day of 2022 to date yesterday, with temps in the single-digit range for all but a few hours and a maximum of just 12.1°C. That's the sort of weather when you'd pretty much expect snow on the Stirling Range. Locals knew it too, heading out in large numbers (as you can see in this ABC Video) to catch a glimpse of a weather phenomenon which generally only occurs once or twice a year in Western Australia. How unusual is snow in WA? As mentioned, it actually happens once or twice a year, but snow can fall as early as Easter and as late as mid-Spring. The Stirling Range is only an hour or so north of Albany at a latitude of 34.3° South. That would place it roughly halfway between Sydney and Canberra (on a north-south axis) if it were on the east coast. The highest point, Bluff Knoll, is a 1099 m summit. Again, to use an east coast example, that makes it similar in height (and latitude) to Blackheath, the Blue Mountains town two hours west of Sydney that also tends to receive one or two snowfalls each winter. So while some people may wake up this morning and go, "What??? It snowed in WA? Has the world gone crazy?" this is actually far from an uncommon event. As mentioned earlier, you just need a particularly cold airmass in the wake of a cold front, and the chart on Tuesday afternoon snows how the air striking the region around Albany has tracked northwards direct from polar region. You can also see that it tracked a fair way north along WA's west coast, which is why places like Geraldton struggled to get past the mid-teens on Tuesday. The good news for chilled-to-the-bone West Australians is that temps should warm in coming days with showers clearing too. The bad news is that the next front arrives on the weekend bringing showers, although temps likely won’t be quite so cold this time. Oh, and for the record, your humble correspondent has hiked to the summit of Bluff Knoll. It's a good challenging day walk, about two hours each way from the car park for fit people (so yeah, it took more like three hours each way!) The views from the top are absolutely sensational.
Weather in Business
11 Jul 2022, 3:11AM UTC
Record month for wind power in Australia's National Electricity Market
New data shows June was one of the best ever months for renewable energy in Australia’s National Electricity Market and a record-breaking month for wind power. June 2022 was a relatively dry and cool month for much of eastern and southeastern Australia, with frequent periods of strong winds and clear skies. NSW registered its driest June since 1986, while Sydney and Brisbane had their sunniest June since 2004. This abundance of sunshine and wind created an ideal month for renewable energy generation in the National Electricity Market (NEM). The combined generation of solar (rooftop and utility), wind and hydropower across the NEM in June 2022 was 5,969 Gigawatt hours (GWh). This is the third highest monthly volume of renewable energy generation in the NEM in records dating back to 1998. Wind power Wind power had a record-breaking month in the NEM, with 2,527 GWh of generation in June 2022 beating the previous monthly record of 2472 GWh from July 2021. Victoria also set a new record for wind power in June this year, with 1,073 GWh easily surpassing the state’s previous record of 922 GWh from July 2021. Solar Power Solar power also had a strong month, with rooftop generation in June outperforming May 2022, despite May usually being the sunnier month. This was the first year on record where June rooftop solar generated more power than May. Utility solar also continued to see strong growth, producing 589 GWh in the NEM during June 2022, which was a big step up from 445 GWh in June 2021. Hydropower While June was a very dry month for large areas of eastern and southeastern Australia, an abundance of rain earlier in the year ensured that there was plenty of water available for hydropower. The NEM received 1,885 GWh of electricity from hydropower in June 2022, which was the 8th highest monthly value in 283 months of records dating back to 1998. The combination of favourable weather and continued growth in the sector caused June 2022 to be an exceptional, and in some cases record-breaking month for renewable energy in the NEM.
21 Jun 2022, 3:53AM UTC
La Nina floods make NSW ports too fresh for ships
La Niña has had a surprising impact on shipping operations in NSW this year, with increased freshwater outflows from flooded rivers affecting the behavior of ships entering some ports. Ships entering tidal ports in NSW are affected by local weather conditions, tides and waves, which can all affect a vessel’s ability to enter and operate safely within a port. One of the important things to consider when allowing larger vessels to enter NSW ports is the tide, which needs to be high enough to allow deep drafted vessels to enter, navigate and exit a port safely. This year, the window of time where water levels are high enough for ships to enter some NSW ports has been reduced by enhanced freshwater inflows from heavy rain and flooding. Image: Rainfall between January and May 2022 was in the top 10 percent of historical records for most of eastern NSW, with some areas receiving their highest rainfall on record for this period. Source: Bureau of Meteorology Freshwater is less dense than salt water, which allows ships to sit lower in the water. The prolific flooding seen in parts of eastern NSW earlier this year caused huge injections of freshwater into the coastal zone, which decreased salinity and affected shipping operations. According to Philip Perkins, Meteorologist and Sales Executive of Ports, Offshore and Safety at Weatherzone, "port users and operators at river-based terminals have been impacted by summer and autumn rainfall. “During high river flows water salinity is reduced. This means vessels can behave differently, resulting in elevated risk to vessels even at berth. Even when secured properly, berthed vessels can be impacted by passing traffic in the terminal.’’ In addition to the safety of ships, decreased salinity at river-based terminals can also reduce the window of time where larger vessels can enter these ports. In some cases, this may force ships to wait for the next high tide before entering or departing the port. Fortunately, river levels and discharge rates have now returned to more normal levels in eastern NSW. However, the ongoing influence of La Niña and a developing negative Indian Ocean Dipole increases the risk of more flooding in the months ahead. With the ground still holding a lot of water, any periods of heavy rain this winter and spring are likely to cause flooding, which may have immediate impacts on shipping operations.