Southwest monsoon onset over southern India in the next two weeks

The Indian Meteorological Department (IMD) is responsible for tracking the advance and retreat of the monsoon over India. This weekend, the IMD issued the first progression of the northern limits of the southwest monsoon, just reaching the Andaman Sea and Andaman & Nicobar Islands on 16 May 2026, over the southern reaches of the Bay of Bengal. According to the IMD, the monsoon onset is likely to reach Kerala on 26 May 2026 (with a model error of ± 4 days), five days ahead of the normal onset date of June 1st.

Image: Advance of the 2026 southwest monsoon onset (blue) and the normal dates of onset (red). Source: IMD

To make this early forecast onset date the IMD monitors these key monsoon predictors:

• Minimum temperatures over Northwest India;
• Pre-monsoon rainfall peak over South Peninsula;
• Cloudiness over the South China Sea and northeast Indian Ocean; and
• Trade wind strength over the southeast and northeast Indian Ocean.

The southwest monsoon is characterised by a surge of westerly winds extending 5-7 kilometres above sea level. These winds are laden with moisture from the Arabian Sea, bringing periods of heavy rainfall and squally conditions across much of southern India.

Image: Moisture laden monsoon clouds can be seen on satellite imagery moving from west to east over the southern Bay of Bengal on Saturday, 16 May 2026. Source: DTN

The southwest monsoon usually takes 4-6 weeks to progress into the far north of the country. The Western Ghats, an insurmountable mountain range along the west of India, splits the monsoon into the Arabian Sea and Bay of Bengal branches.

DTN APAC Explainer: The Indian Monsoon

The onset of the monsoon over the Indian sub-continent brings relief from sweltering heatwaves, but the heavy rainfall led to significant disruptions to transport, energy and mining sectors. The monsoon rains are also imperative to India’s agriculture sector, with about three quarters of India’s rainfall occurring during the monsoon season. Nearly half of the Indian population is employed by the agricultural sector, which contributes greatly to the country’s economy.

How climate drivers will impact the 2026 Indian summer monsoon

The IMD predicts below normal rainfall (95-90% of the Long Period Average (LPA)) across India during the 2026 southwest monsoon season.

The dominant factor driving the below average rainfall expected during the coming monsoon season is the predicted strong El Niño developing in the equatorial Pacific Ocean. While occurring in a different oceanic basin, El Niño events shift the Walker Circulation pressure pattern, leading to higher than normal pressure over the eastern Indian Ocean and weaker monsoonal winds. As a result, El Niño events are typically associated with reduced monsoonal rainfall and increased potential for drought, especially over northwestern and southeastern India.

More locally, the Indian Ocean Dipole (IOD) could move towards the positive phase late in the monsoon season. Positive IOD events are characterised by warmer than average waters in the IOD West region (see below), near the Horn of Africa. Warmer waters to the southwest of India increase the moisture content of monsoonal winds and can lead to increased rainfall during the rainy season. If this positive IOD event can become established, it will most likely peak after the end of the southwest Indian monsoon season, which runs till about September, but could contribute to increased monsoonal rainfall late in the season.

Image: Sea Surface Temperature Anomaly forecasts across the Indian and Pacific oceans during September 2026, showing the strong El Niño and possible positive IOD events. Source: DTN

Another factor that seasonal forecasters need to consider ahead of the monsoon season is the northern hemisphere snow cover, especially around Siberia. The start of 2026 saw slightly below average snow cover extent, which can increase land warming during the springtime (reflecting less solar energy). This allows warm air to rise to the north of India, decreasing the pressure and drawing stronger monsoonal winds early in the season. As a result, an earlier monsoon onset over the sub-continent is possible in the coming weeks.

Under the influence of these climate drivers, along with seasonal computer modelling, the IMD predicts India will experience 92% of the Long Period Average (LPA) monsoon season (June to September) rainfall, with a model error of ±5%. While below average rainfall is forecast across broad parts of the country, parts of northeastern, northwestern and South Peninsular India could see average to above average rainfall, as seen in the seasonal model output below.

Image: Probability forecast of below normal (yellow to red), normal (green) and above normal (blue) of 2026 southwest monsoon season (June to September) rainfall across India. Source: IMD

The 2025 southwest monsoon season featured heavy rain periods. The cumulative rainfall across the country throughout the season was 937.2mm, 107.9% of the long period average (LPA) of 868.6mm.

DTN APAC’s review of the 2025 southwest monsoon season

Excesses or deficiencies in monsoonal rainfall can lead to floods or droughts, impacting India’s food security, livelihood and overall economy. Replenishments of water resources like rivers, lakes and groundwater vital for irrigation and drinking water supplies also impact hydropower energy generation.

How DTN APAC supports businesses through seasonal changes in tropical cyclones and monsoonal rain activity

DTN APAC specialises in industry-leading forecast, alerting and threat analysis of tropical cyclones across Australia, Asia and India, offering you expert, customised solutions when the weather turns wild.

Providing rapid-update forecast information, we alert you to any low-pressure system gaining power within your region and, unlike other providers, can track its development out to 7 days. This gives you the time to prepare and safeguard your staff, sites and assets.

You will have the most precise weather intelligence charting rainfall, wind speeds and potential storm surges to help you make critical decisions quickly. Whether it’s adjusting key work schedules, protecting your staff or securing your site, we have the alerting capability to keep you steps ahead of the storm.

As the climate delivers increasingly severe weather events, their potential to impact your business operations grows.

Whether it’s preparing for the coming season’s tropical storm potential, or rapid-response forecasting with a typhoon approaching, or simply ensuring your operations team is equipped to confidently make decisions ahead of severe weather, our weather Risk Communicators are here for you.

Our weather Risk Communicators deliver short- to long-term guidance, including:

• Hourly-event weather monitoring (alerting you of impending destructive winds and heavy rain ahead of a tropical cyclone);
• Week to month operational planning based on likely timing of increased monsoonal rain or periods of reduced cyclone activity; and
• Seasonal long-term planning based on climate drivers and the likely trends across the coming months.

We deliver clear and comprehensive weather data, personalised risk assessments and briefings to you and your team, so that your critical decisions can be made with confidence.

We are available 365 days a year, so you always have the timely guidance you require, especially when severe conditions hit.

You have our insights to rely on to see you through complex situations, minimising potential loss of profit and maximising the safety of your staff and assets.

Learn more about our large range of industry-leading products and services or email us at sales.apac@dtn.com

The post The 2026 Indian Southwest Monsoon onset is expected in the next two weeks appeared first on DTN APAC.

The 2025–26 Australian tropical cyclone season officially ran from 1 November 2025 to 30 April 2026. During this six-month period, Australia saw 11 tropical cyclones, with nine forming within the Australian region and two forming outside of Australia’s area of responsibility. Five of these systems made landfall, bringing severe weather to parts of the country. 

While eleven cyclones is slightly above the long-term average of 9.5 systems, the season was notable for an unusually high proportion of severe cyclones forming in the region. Of the eleven cyclones, seven systems reached severe intensity (Category 3 or higher), compared to a historical average of approximately 4–5 severe cyclones per season. 

The seven severe systems of the 2025–26 season were Narelle (Cat 5), Maila (Cat 5), Fina (Cat 4), Bakung (Cat 4), Hayley (Cat 4), Jenna (Cat 4), and Mitchell (Cat 3). Of the seven severe tropical cyclones, four made landfall on the Australian mainland, with Narelle notably crossing the coast multiple times across different states/territories. 

Cyclone activity during the season was not evenly distributed, with peak periods occurring during monsoon onsets and when tropical pulses such as the Madden–Julian Oscillation (MJO) were active. The most active period occurred between February and March 2026, when the monsoon trough, MJO and warm ocean temperatures coincided. 

Wet season

The season also delivered above-average wet season rainfall across northern Australia, driven by monsoon lows, tropical cyclones and the background influence of warm SSTs and La Niña. Pockets of far north Queensland, the western Top End and the Kimberley in WA saw the highest rainfall on record.   

Image: Australian rainfall deciles between 1 November 2025 to 30 April 2026, source: Bureau of Meteorology 

The Top End wet season officially runs from the start of October to the end of April. To 9am this Thursday, April 30 (in the unlikely event of rain after 9am, it will be counted in May’s total) Darwin recorded: 

• 2397.4mm of rainfall across the wet season, which made it the 4th-wettest on record.  

• The average across the season in 157 years of records is 1691.7mm. 

• Above-average rainfall in each of the last six months of the season from November through April. The only other time that happened was in 2016/17. 

Persistent rainfall events limited recovery windows between systems, increasing flood risk, while frequent thunderstorm activity introduced additional hazards including lightning, damaging winds, and intense rainfall rates—compounding operational disruption for weather-sensitive industries. 

Climate drivers 

The intense season occurred under the combined influence of above-average sea surface temperatures (SSTs), a warming climate background, and a La Niña event declared by the Bureau of Meteorology on 27 November, which persisted into early April 2026. 

Additionally, exceptionally warm oceans surrounding northern Australia—approximately 1 to 3°C above average in key regions—provided significant additional energy for cyclone development. This was the dominant driver of intensity, supporting: 

• Rapid intensification events  

• Higher peak cyclone intensity  

• Longer-lived severe systems  

The northern Australian monsoon arrived earlier than usual on 23 December 2025, marking the first active phase of the wet season -typical of La Niña years, which often see an earlier onset. 

Once established, the monsoon became highly active and moisture-rich, contributing significantly to both rainfall and cyclone development. 

Tropical cyclones and monsoonal lows also contributed significantly to seasonal rainfall totals, particularly inland, with above to very much above average rainfall observed across northern Australia. 

Regional distribution vs climatology 

The 2025–26 season broadly followed the typical spatial pattern; however, the western region saw more cyclones than normal with nine forming or moving into the area.  

Cyclone trend in Australia: fewer cyclones, greater intensity 

The number of tropical cyclones in the Australian region has decreased in recent decades, with an average reduction of around one system every 11 years since 1980, likely linked to broader climate change influences. 

This long-term decline also reflects strong ENSO variability, with La Niña years typically producing more cyclones, while El Niño years are associated with fewer systems. 

While total cyclone numbers are decreasing, the proportion of severe cyclones is increasing. Warmer ocean temperatures are a key driver of this trend, supporting more frequent rapid intensification and higher peak intensities. 

Forecast performance and operational response 

Ahead of the season, DTN APAC’s seasonal outlooks accurately projected a slightly above-average number of cyclones, alongside an elevated risk of severe systems, communicated through detailed briefings to clients across northern Australia. 

The impactful season meant that our team of risk communicators provided extensive support to clients, including: 

• 96 tropical cyclone briefings  

• 1,750 email advisories  

This reflects sustained engagement across multiple cyclone events and prolonged impacts. 

Tropical Cyclone Narelle- the most impactful system of the season 

Tropical Cyclone Narelle accounted for a disproportionate share of operational activity due to its duration and multi-region impact. It is highly unusual for a system to cross three Australian jurisdictions (Queensland, the Northern Territory, and Western Australia), making Narelle a rare “triple-impact” cyclone. 

This type of track is extremely uncommon in modern records. Narelle became the first tropical cyclone since 2005 to make landfall in three Australian states while maintaining tropical cyclone intensity, with the only other comparable cases since 1980 being Cyclone Ingrid (2005) and Cyclone Steve (2000). 

Narelle reached severe intensity across three Australian states and territories, with our meteorologists supporting exposed clients with the following; 

• 48 briefings (~50% of seasonal total)  

• 790 advisories 

Narelle highlights how a single long-track system can dominate seasonal risk exposure. 

With climate change, this shift toward fewer but more powerful systems is becoming increasingly important for forecasting, planning, and operational resilience across weather-sensitive industries. 

Through our weather intelligence and risk communication services, DTN APAC helps businesses prepare for and respond to severe weather impacts, including tropical cyclones, intense rainfall. For more information, take a look at our 7-Day Tropical Cyclone Service and Risk Communicators. 

The post Australia’s 2025–26 Cyclone Season: Slightly Above Average, Dominated by Severe Systems appeared first on DTN APAC.

El Niño on the horizon

The tropical Pacific Ocean is currently in a neutral state, meaning neither El Niño nor La Niña are occurring. However, there are strong indications that El Niño will emerge as we head into the Southern Hemisphere’s winter.

The first indicator of the looming El Niño is a large pool of abnormally warm water sitting beneath the surface of the tropical Pacific Ocean.

El Niño occurs when sea surface temperatures in the central equatorial Pacific Ocean – an area called the Niño 3.4 region – become warmer than average. The Bureau of Meteorology’s threshold for El Niño is at or above 0.8°C warmer than average in the Niño 3.4 region, while some other countries, including the United States, use a lower threshold of 0.5°C above average.

While ocean surface temperatures in the Niño 3.4 region are currently near average for this time of year, there is a large slab of unusually warm water sitting around 50 to 250 metres below the surface. These above-average sub-surface temperatures have strengthened in the last couple of months, with anomalies exceeding 6°C in some areas. It’s possible that these warm sub-surface waters will upwell towards the surface in the coming weeks and months, which could kick off El Niño.

Image: Sub-surface temperature anomalies in the equatorial Pacific Ocean from early March to early April, 2026. The red shading inside the green box shows abnormally warm water lying beneath the surface of the tropical Pacific Ocean. Source: Bureau of Meteorology.

A second sign that El Niño is about to emerge is overwhelming agreement between global forecast models.

At this time of year, we typically see a lot of uncertainty in forecasts for El Niño and La Niña due to a phenomenon called the autumn predictability barrier in the Southern Hemisphere (spring predictability barrier in the Northern Hemisphere). However, there is strong model consensus that El Niño will develop in the next few months.

Some models also predict that the imminent El Niño will become a very strong event – what is sometimes referred to as a ‘super El Niño’ – meaning sea surface temperatures in the Niño 3.4 region will reach 2.0°C above average or higher. According to the National Oceanic and Atmospheric Administration Climate Prediction Centre’s latest forecast, there is roughly a 25% chance of a very strong El Niño occurring towards the end of this year.

Image: El Niño forecast plume from the ECMWF SEAS5 model. Each red line represents a forecast from one of 51 different ensemble members from the same model. Each member uses slightly different initial ocean conditions as the basis for its forecast, which helps account for a range of possible scenarios in the forecast. Note that all ensemble members from this model are predicting El Niño conditions from May and most are suggesting a very strong, or ‘super’ El Niño later in the year. Source: ECMWF (annotated by Weatherzone).

What does El Niño mean for Australia?

El Niño does not guarantee any kind of weather for Australia. However, it does make some types of weather more likely than others, particularly during winter and spring.

The maps below show the observed changes to rainfall and maximum temperature from past El Niño events. These maps show conditions averaged out across multiple 9 or 10 El Niño years, representing the general impact of El Niño on daytime temperatures and rainfall.

Image: Observed rainfall deciles for the July to September period during 10 El Niño events from 1905 to 2015. The red shading shows where rainfall is below average. Source: Bureau of Meteorology.

Image: Observed maximum deciles for the August to October period during nine El Niño events from 1914 to 2015. The orange and yellow shading shows where maximum temperatures are above average while blue is below average. Source: Bureau of Meteorology.

In general, El Niño typically causes:

• Below average rainfall over large areas of Australia during winter and spring. However, its influence on rainfall is usually weaker in summer and autumn.
• Above average maximum temperatures for most areas outside the tropics, particularly during the second half of the year. In the tropics, El Niño typically reduces maximum temperatures in the dry season and makes days warmer in the wet season.
• Enhanced evaporation due to above average temperatures and below average rain, which can cause of enhance drought.
• More intense daily heat extremes in southern Australia, but with a reduced frequency of prolonged heatwaves.
• Increased frost risk in winter and spring due to enhanced radiative cooling with clearer skies.
• Increased risk of dangerous fire days in southeastern Australia as temperatures rise in spring and summer.
• Decreased seasonal peak alpine snow depths and a shorter snow season.

The strength of El Niño can also affect how it influences Australia’s weather. Stronger El Niño events make it more likely that the impacts mentioned above will occur. However, it is important to point out that stronger events do not always mean bigger weather impacts and even a weak El Niño can cause significant weather and climate impacts in Australia. It’s also worth noting that no two El Niño events are the same and other external influences, such as regional ocean temperatures near Australia, and other climate drivers, such as the Indian Ocean Dipole (IOD), will likely affect how El Niño impacts Australia in the coming months.

DTN APAC helps businesses navigate climate volatility by providing high-precision, actionable weather intelligence, forecasting and risk management tools. We offer tailored solutions to protect assets, ensure worker safety, and optimise operations for industries like energy, mining, and transport, reducing financial losses from severe weather.

The post What does a ‘super El Niño’ mean for Australia’s businesses? appeared first on DTN APAC.

Intense and hazardous Tasman Sea

Ocean conditions across NSW’s South Coast rapidly deteriorated last Friday as a deep feed of easterly winds whipped up large and dangerous seas. The Batemans Bay Surfrider buoy recorded an increase of nearly 3 metres in significant wave heights in the 8 hours to 9pm on Friday.

Image: Significant wave height recordings from Surfrider buoys off the NSW coastline between Thursday and Tuesday, January 15-20, 2026. Source: Manly Hydraulics Laboratory.

The surge of large east-to-southeast swell moved up the coast throughout Friday and into the weekend, with maximum wave heights reaching over 9 metres off the Sydney coast on Saturday morning. A Coastal Hazard Warning for Damaging Surf was issued for coastal areas south of Seal Rocks around this peak period of swell activity.

Week of activity in the Tasman and Coral seas

Video: 10 metre wind speeds across the Tasman and Coral seas this week showing areas of swell generation directed towards Australia’s East Coast.

As seen in the video above, storms in both the Tasman and Coral seas have continued to blow strong easterly winds into this week, directing persistent swell towards the East Coast of Australia.

While the largest waves were experienced on Saturday, the swell is not expected to drop below 2 metres across much of coastal NSW between the weekend and much of this working week. Lengthy periods of significant swell can cause long lasting delays across shipping routes with port operations being impacted.

Video: Significant wave heights across the Tasman and Coral seas this week.

Coasts between Jervis Bay and Seal Rocks, including Sydney, will receive the highest energy across the period, with much of this energy coming from longer period swell from the east to southeast. This combination of size, period and direction is particularly notorious for causing significant coastal erosion, disruption to port, ferry and maritime operations, and bringing deceptively powerful surf and rip currents.

Video: Peak wave period across the Tasman and Coral seas this week.

Tropics buzzing with energy

Port, shipping and offshore operations across northern Australia are also on high alert with increased tropical activity currently affecting the region. Two potential tropical lows, 16U and 17U, are currently being monitored for potential tropical cyclone intensification this week

Image: Chances of Tropical Low 16U and 17U forming into tropical cyclones on Thursday afternoon. Source: BoM

DTN APAC is currently offering support through ongoing briefings and forecasts to port and maritime operations that may be impacted by either of these systems. By providing the latest meteorological forecasts, our customers are able to make informed decisions regarding deployment or harbouring of ships, tropical cyclone tie-down proceedures, or workload management, well ahead of the first signs of the system approaching.

How DTN APAC assists marine, ports and offshore industries

DTN APAC offers a comprehensive suite of services, refined through years of collaboration with the marine, ports and offshore industries, to optimise the safety and efficiency of your operations.

We work with you to understand your intrinsic operational challenges and customise high-precision forecasting, metocean and aviation services to your exact location and operational scope.

When working offshore, our solutions can underpin planning and safe execution for offshore oil and gas enterprises and wind farms. Our data can support your exploration, development, rig moving, shuttle tanker operations, and production and decommissioning phases. Whether your crews are on-site, being transported to shore, or diving to perform maintenance, we deliver tailored weather risk briefings to ensure you choose the optimal time to proceed.

DTN APAC’s trusted nowcasting and forecasting system, OpticastTM, allows you to rapidly respond to changing conditions offshore, en route and in port. We take your port topography and berth orientation into account, ensuring site-specific forecasts. For offshore oil & gas, wind farms, ports and logistics, we have your weather situational awareness covered, no matter where you are. We deliver real-time severe weather and lightning alerts to your team via your integrated dashboard: Portzone, and our Weatherguard app.

DTN APAC’s Total Lightning Network (TLN) ensures you avoid hours of unnecessary downtime by providing the most accurate technology in lightning detection and alerting. Safeguard your teams and assets with lighting and Dangerous Thunderstorm Alerts (DTAs), customised to your existing parameters and delivered in real-time across all devices in your network. You gain full spatial awareness of developing severe weather systems, allowing you to plan ahead and, where needed, execute your shutdown and evacuation procedures.

With extreme conditions slowing production and affecting infrastructure, safety and transport, trust us to deliver Australia’s most precise weather data and tailored insights, giving you decisive confidence when it’s most needed.

Learn more about our large range of industry leading products and services or email us at sales.apac@dtn.com

Thumbnail image source: iStock / Page Chichester.

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Rainfall rates between 80 and 140mm in one to three hours were registered across parts of Sydney’s Northern Beaches and Central Coast on Saturday afternoon and evening. In some areas, these rainfall rates are comparable to the tropics and are equivalent to one in 200-to-500-year events. This intense rainfall was caused by a deep feed of moist easterly winds coming off the very warm Tasman Sea, directed over the region by a coastal trough. Parts of the Pacific Highway that connect Sydney to Brisbane, and the Central Coast train line that connects Sydney to Newcastle and beyond, was heavily disrupted by the localised flooding.

Video: 6-hourly rainfall estimates and rain gauge observations since 9am on Saturday morning, as seen on the DTN APAC Stormtracker dashboard.

Further heavy falls have continued overnight, with many locations experiencing their heaviest rain in one to two years. Notable 24-hour rainfall accumulations to 9am Sunday include:

• 346mm at Palm Beach Golf Club
• 264mm at Great Mackeral Beach
• 260mm at Wattamolla
• 250mm at Pearl Beach
• 242mm at Woy Woy
• 209mm at Ettalong
• 194mm at Avalon
• 180mm at Terrey Hills (wettest day on record for the station, with records since 2005)
• 129mm at Norah Head (wettest January day on record, with records since 1996, and wettest day since October 2020 – 5 years ago)
• 134mm at Wisemans Ferry (wettest day since March 2021 – nearly 5 years ago)
• 124mm at Sydney Obs Hill (wettest January day since 1988 – 38 years ago)
• 103mm at Bankstown (wettest January day since 2001 – 25 years ago)
• It was the wettest January day on record (records since year) for these stations: Camden Aiport (140mm – since 1943), Penrith (105mm – since 1996), Mount Boyce (142mm – since 1995), Campbelltown (126mm – since 2007) and Gosford (125mm – since 2014)
• Over 90 locations across NSW with over 100mm

Image: Estimated 24-hour rainfall accumulations and rain gauge observations since 9am on Saturday across the Greater Sydney Metropolitan region, as seen on the DTN APAC Stormtracker Dashboard.

Road and train networks were disrupted by the flash flooding, with Sydney Trains having to halt rail movements between the Central Coast and Sydney, and the slowed the arterial Pacific Highway that connect Sydney to Newcastle and Brisbane. Flooding, combined with strong winds, has caused trees to fall across roads, houses and powerlines, with the SES and power networks responding to thousands of calls for help and outages. Flood prone areas like Narrabeen Lagoon in Sydney’s Northern Beaches have also been evacuated.

Over 19,000 lightning strikes have also been recorded within 100km of Sydney since midnight on Friday, most of which were over the northern suburbs and Central Coast areas.

Heavy rainfall continues to move into the Sydney Basin on Sunday morning, but conditions gradually improved into Monday. As seen in the animation from DTN APAC’s Stormtracker Dashboard below, the heaviest falls contracted north into Sunday afternoon, with showers and more isolated heavy rain extending into Monday.

Video: 6-hourly rainfall rates and 10m wind speeds according to the high-resolution ACCESS-C Sydney computer model.

How DTN APAC’s unique data sources are helping NSW businesses

We help businesses in Australia, Asia and the Pacific prepare for flooding rainfall and other severe weather, across sectors including Roads and Transportation, Emergency Services, Mining, Insurance and Energy.

Grounds are saturated around Sydney and eastern NSW, leaving businesses and industries vulnerable to flooding, toppling of trees and other weather risk hazards.

Our Long-Range Weather Forecasting spans from 14 day to 12 month forecasts.

These forecasts are produced by our meteorologists using raw data provided by international weather agencies.

These forecasts are produced using a combination of techniques, some in the public domain and others developed by DTN APAC.

Our Risk Communicators can then work closely with you to analyse how weather impacts your operations and communicate potential risks. We can then support your risk management planning, and provide situational awareness and post-event reporting when extreme weather events hit hard.

Find out more about our our large range of industry leading products and services or email us at sales.apac@dtn.com

The post Transport, emergency and energy industries flooded across Greater Sydney with weekend deluges appeared first on DTN APAC.

DTN operates Dangerous Thunderstorm Alerts (DTA) which alert businesses and industries to thunderstorms based on intensity and movement. These alerts provide advanced notice of thunderstorms moving into an area. The animated loop below shows DTAs in action over the Perth region on Sunday, as seen on DTN APAC’s Stormtracker dashboard.

Video: DTN APAC Stormtracker’s Radar, Dangerous Thunderstorm Alerts (DTA) and Total Lightning Network with severe thunderstorms moving over the Perth region on Sunday, December 14, 2025.

Three levels of thunderstorm alerting are provided by DTN: Level 1 (blue), Level 2 (yellow) and Dangerous Thunderstorm Alert (red). Alert levels are based on lightning frequency and density, and color-coded thunderstorm track polygons are provided to indicate the areas likely to be impacted in the next 30 minutes.

Image: DTN Level 1 and 2 thunderstorm alerts in action on Sunday, December 14, 2025.

Early warnings for thunderstorms can be incorporated into Trigger Action Response Plans (TARPs) for industries such as aviation, shipping, transport and utilities where lightning poses a serious risk to outdoor workers. Severe thunderstorms also pose a significant risk to expensive machinery with destructive wind gusts and large hail, bringing possible disruptions to the supply and industry chain resulting in costly insurance bills.

Thunderstorm activity started shortly after midday on Sunday, with powerful thunderstorms tracking south to southeast across the region. Between midday to midnight on Sunday, nearly 615,000 lightning strikes (over 135,000 recorded as ground strikes) were detected by DTN’s Total Lightning Network (TLN) across western WA.

Image: DTN’s Total Lightning Network (TLN) detected a total of 614,840 lightning strikes within 500km of Dalwallinu between 12pm AWST Sunday, and 12am AWST Monday, December 15, 2025. Of the total lightning strike amount, 135,919 were recorded as ground strikes.

Notable wind gusts recorded with these severe thunderstorms include:

• 107 km/h at Ejanding at 3:38pm
• 100 km/h at Perth Airport at 4:03pm
• 94 km/h at Meekatharra and Pearce at 2:55pm and 4:10pm, respectively
• 92 km/h at Moora at 2:54pm

While storms remained active across the region throughout the afternoon and evening, most areas only received heavy rainfall for an hour or so, resulting in:

• 26mm at Long Pool in the hour to 3:50pm
• 17mm at Perth Ap (wettest December day in 14 years)
• 7mm at Dalwallinu (wettest December day in 13 years)
• The wettest December day in 8 years for Perth (15mm), Swanbourne (3mm), Pearce (14mm), Jandakot (6mm) and Bickley (13mm)

Damaging winds and flash flooding quickly moving over infrastructure with thunderstorms can catch operators off guard and unable to safely complete storm mitigation procedures.

How DTN APAC’s Total Lightning Network (TLN) and now-casting solutions are helping mining, transport, shipping and utility industries with severe thunderstorm warnings

Our Total Lightning Network is the intelligent lightning solution that goes above and beyond to alert lightning and increase your lead time before the storm hits.

We utilise a vast global sensor network, created with our partner Earth Networks. Over 1200 sensors in 40+ countries provide a worldwide view of both intra-cloud (IC) and cloud-to-ground (CG) lightning strikes, enabling businesses to plan and respond with the most precise insight available. The highest density of sensors across Australia and the globe give you the edge.

Real-time monitoring and alerting enhance safety outcomes whilst also preventing costly shutdowns caused by inaccurate sensor data. Our system provides early warning of approaching storms by tracking lightning activity, alerting you with the positive charge buildup that often precedes a strike, making it easier to detect potential threats.

Offering unsurpassed accuracy, with real-time sensing to <200m, we integrate with your existing systems to keep your enterprise operating within your defined severe weather thresholds. Our technology also helps monitor radiation from electrical discharges and ensures every lightning flash is accounted for.

Visualise approaching storms as our customisable GIS system, Stormtracker, plots strike data across your site and infrastructure. This enables enhanced understanding of the potential risk inherent in each severe weather system and how storms produce hazardous conditions. Integrated satellite technology improves tracking accuracy, while real-time weather forecasts provide deeper insights into developing thunderstorm activity and potential disruptions.

Leave nothing to chance. Be confident working outdoors with the most sophisticated lightning alerting system, delivering intelligence to any device across your business network. Whether you need a personal lightning alerting tool for individual safety or enterprise-wide monitoring, our solution is designed to emit timely alerts and protect your operations.

Learn more about our large range of industry leading products and services or email us at sales.apac@dtn.com

The post DTN Dangerous Thunderstorm Alerts in action with severe thunderstorms disrupting Perth industries appeared first on DTN APAC.

Clear skies associated a large and slow-moving high pressure system have allowed hot air to build up over parts of northern, western and central Australia this week. This hot air will spread across southern and southeastern Australia between now and the weekend under the influence of a broad low pressure trough, which will also cause wind to strengthen over several states.

Temperatures rising over all of southeastern Australia in the next few days will bring severe heatwave conditions and high energy demand. The burst of heat and windy conditions also brings disruptive elevated fire danger ratings to parts of SA, Victoria and NSW.

South Australia

North to northwesterly winds are strengthening over SA on Thursday as the low pressure trough deepens over the state. These blustery winds are driving hot inland air towards the south, causing temperatures to reach about 34°C in Adelaide and 36°C around Keith. Further north, temperatures are likely to exceed 40°C in the state’s Pastoral districts on Thursday.

Image: Forecast maximum temperatures on Thursday, December 4, 2025.

The combination of heat, blustery winds and low relative humidity have caused Extreme fire danger ratings over central and eastern part of SA on Thursday. Total fire bans have been declared in eight of the state’s 15 districts:

• Eastern Eyre Peninsula
• Flinders
• Mid North
• Yorke Peninsula
• Mount Lofty Ranges
• Riverland
• Murraylands
• Upper South East

Milder southerly winds will drop temperatures and fire danger ratings in the state’s south from Thursday afternoon into Friday, although intense heat will linger in the north of SA until Saturday. While Adelaide is only forecast to reach 22°C on Saturday, some northern pastoral areas could reach the high-40s on Saturday afternoon.

Victoria

All of Victoria will be affected by a surge of hot northwesterly winds on Thursday, with temperatures forecast to reach 34°C in Melbourne, 36°C in Mallacoota and 38°C in Mildura. Extreme fire danger ratings are likely to develop in parts of the Mallee, Wimmera and Northern Country districts amid this heat on Thursday, with total fire bans declared for all three districts.

Image: Forecast fire danger ratings and total fire bans as seen on the DTN APAC Stormtracker dashboard on Thursday, December 4, 2025.

Milder southwesterly winds will spread through southern Victoria from Thursday afternoon into Friday, although northern Victoria will remain hot on Friday before cooling over the weekend. Extreme fire danger is expected to linger in parts of the Mallee and Northern Country districts on Friday.

New South Wales

Hot air will spread over NSW from Friday into the weekend, causing a spike in temperatures and fire danger ratings.

Sydney’s daily maximum temperatures are forecast to reach 30°C on Thursday, 35°C on Friday and 36°C on Saturday. The city’s western suburbs will be several degrees warmer, likely reaching around 40-41°C on Friday and Saturday. Temperatures will also reach the low to mid-40s in western NSW on Friday and Saturday.

Image: Forecast maximum temperatures on Saturday, December 6, 2025.

Increasingly warm overnight conditions over this period, with Sydney’s minimum temperatures forecast to only drop to 19°C on Friday, 23°C on Saturday and 20°C on Sunday, will prevent overnight relief from the heat. Severe heatwave conditions are forecast across the period, with high energy demand expected on Friday and Saturday as energy customers turn on A/C units to cool off.

Image: Forecast heatwave conditions between Thursday and Saturday, December 4-6, 2025.

Extreme fire danger ratings are likely to develop in parts of southern NSW on Friday and central, eastern and northern NSW on Saturday. Saturday’s Extreme fire danger is likely to affect parts of the Greater Sydney, Greater Hunter and Illawarra/Shoalhaven districts.

Image: Forecast fire danger ratings as seen on the DTN APAC Stormtracker dashboard on Saturday, December 6, 2025.

Thunderstorms igniting fires possible

While much of southeastern Australia will experience hot and windy weather over the next few days, some places could also see thunderstorms.

The atmosphere is too dry for widespread storms and heavy rain, so storms are likely to be scattered and fast-moving. The biggest threats from these storms will be damaging and possibly destructive winds, and dry lightning, which could ignite bush or grass fires.

Heat and thunderstorm activity will also spread further north into northern NSW and Queensland on Sunday and Monday.

Read our 2025-26 summer bushfire outlook: Heightened bushfire risk during the 2025-26 summer for WA, Victoria and NSW in latest AFAC Outlook

How DTN APAC Services Fire-Prone Outdoor Industries

Working in often challenging conditions across high-risk outdoor operations including forestry, emergency services, mining, rail, and utilities, our consolidated weather services ensure full situational awareness for you and your team.

DTN APAC serves fire-prone outdoor industries, delivering trusted weather data and severe weather alerting to maintain safety, protect your assets and underpin your operational planning.

Reinforce your Prevention, Preparedness, Response and Recovery (PPRR) efforts with our tailored services.

Prevention: Utilise our seasonal outlooks and daily forecasting to identify and implement prevention measures. Understand the climate risks affecting your operations. Calculate optimal timing for maintenance activities, vegetation management, and scheduled shutdowns.

Preparedness: Gain understanding of bushfire risk in the days, weeks and months leading up to peak fire season. Use DTN APAC’s seasonal outlooks and 14-day forecasting to plan workforce deployment, equipment positioning, and preventative operations such as controlled burns or asset maintenance.

Response: We deliver fire danger forecasts and provide nowcasting and forecasting of severe weather events, including thunderstorm/lightning detection and alerting, to give you full situational awareness of emergency conditions likely to impact your operations and infrastructure.

Recovery: Assess the weather risks affecting post-incident recovery and restoration processes. Utilise post-event analysis reports to support insurance claims, evaluate operational response effectiveness, and inform future risk management strategies.

We work to bring you full situational awareness so you can mitigate risk, ensure workforce safety, and maintain operational continuity across your outdoor assets.

Learn more about our large range of industry leading products and services or email us at sales.apac@dtn.com

See our Case Study on how Tasmania Fire Service (TFS) improved lightning detection and continued optimising preparations for challenging fire seasons ahead with DTN APAC’s full suite of solutions.

The post Extreme fire danger and severe heatwave conditions spreading across SA, Victoria and NSW appeared first on DTN APAC.

Parts of Australia have experienced severe soil moisture and rainfall deficiencies over the past months and years, while high fuel loads (grass, bush and forest) combined with hot and dry weather, should drive elevated fire danger over the coming 2025-26 summer.

Image: The AFAC Seasonal Bushfire Outlook for the 2025-26 summer highlighting key regions of increased risk of fire in the coming months. Source: AFAC.

Key regions that could see “an increased number of significant bushfires occurring in the outlook period compared to average” include parts of:

• western and southern WA
• central northern NSW
• southwest, western, central, north central and southwest Gippsland in Victoria

Overall, much of Australia should experience a warmer than normal summer. Rainfall outlooks for the coming season mostly promote wetter than normal conditions for northern and eastern Australia as a result of weak La Niña conditions in the Pacific Ocean, and very warm sea surface temperatures off Australia’s east and north coasts. Elsewhere should see either normal, or drier than normal conditions over the coming three months.

Western Australia and the Northern Territory

Parts of western and southern WA are highlighted by the AFAC outlook with an increased risk of fire during the coming summer. This follows healthy wet season rainfall during the cooler months which has allowed the fuel loads to grow, combined with a forecast for hotter than normal, and drier than normal conditions over the coming months. This hot and drying trend will allow fuels to dry, increasing the risk of more significant fires, especially during the mid-to-late summer.

Image: Smoke dissipating from active fire over WA’s southwest and south on Monday, December 1, 2025.

Northern WA and the NT are generally expecting normal risk of fire during the summer months, especially with a wetter than normal outlook for the northern Australian wet season. However, parts of the Pilbara, Gascoyne, WA interior and NT interior could still see periods of increased fire activity following a very dry period during the dry season. This is more likely during the early summer with hot and windy conditions, ahead of intrusions of the Australian monsoon.

South Australia, Victoria and Tasmania

Southeastern Australia has benefited from recent rainfall increasing the soil moisture and leading to some vegetation growth. However, the winter and spring rainfall received wasn’t enough to offset the severe rainfall deficits that have plagued much of the region over the past two years.

Image: rainfall deficits across Australia over the last two years. Source: Bureau of Meteorology.

These lingering rainfall deficiencies, combined with a forecast for warmer than normal summer, and normal-to-below average rainfall, could lead to a significant risk of increased fire activity over the latter half of summer. AFAC highlights broad parts of Victoria experiencing this increased risk, notably forest and woodland areas of the south-west, Otways, Mornington Peninsula, southwest Gippsland, Kinglake and Yarra Ranges, and Elidon.

While AFAC’s outlook keeps South Australia and Tasmania within the normal risk of fire this summer, rapid drying of soil moisture and forest, grass and crop fuels could lead to increasing fire risk late in the season. Notably, parts of SA’s Riverland, North East Pastoral, Mount Lofty Ranges and Mid North regions, and Tasmania’s southwest and southeast, could be at risk if very dry, hot and windy conditions become more prevalent this summer.

New South Wales and Queensland

Spring weather was disrupted by a sudden stratospheric warming event leading to stronger cold fronts crossing southern and eastern Australia. While this event brought healthy rainfall to southern states, NSW and Queensland have experienced a number of very hot, dry and windy spells over the past months, helping dry out the landscape and bringing bursts of elevated fire danger.

Read more: How this sudden stratospheric warming event has disrupted Australia’s weather

Hot, dry and windy bursts of elevated fire danger are expected again during December for NSW and southern and central Queensland. As the summer evolves, impacts of this stratospheric warming should ease, and the effects of very warm oceans off the East Coast will increase the probability of wetter than normal conditions, especially across eastern NSW and Queensland. Western and central parts of these states further from this moisture source could see fire risk persist well into summer, with AFAC focusing on central northern NSW in their outlook.

A combination of warmer than normal temperatures, and moisture from these warm oceans, have and will continue to bring increased thunderstorm activity across the region this summer. Lightning has the potential to ignite fires, especially across dry landscape, as they have done a number of times this season.

Image: A series of thunderstorms igniting a fire over central NSW, north of Parkes, on Wednesday, November 26, 2025.

Northern Queensland is transitioning into its wet season, bringing with it subduing of fire danger and vegetation growth, which is normal for this time of year.

What is “normal fire risk”?

Peak fire danger seasons are different across Australia, as seen in the image below.

Image: Peak fire danger seasons across Australia. Source: Australian Institute for Disaster Resilience

Northern Australia experiences its worse fire risk across the back half of the dry season, when the landscape has dried and strong dry winds blow from the interior. Much of Queensland and northeast NSW fire danger peaks during spring following the dry winter, and as temperature and thunderstorms ramp up, but ahead of the wet and humid summer. Southern Australia typically experiences the worse fire danger during summer with hot and dry airmasses moving over from the interior.

It’s important to note that normal fire risk does not mean no fire risk. Under the wrong conditions, vegetation can dry rapidly, and fire weather can be extremely erratic, leading to impactful fires, even in “normal fire risk” zones.

Communities, industries and other stake holders across Australia should remain careful and vigilant of fire weather forecasts throughout the coming season.

How DTN APAC Services Fire-Prone Outdoor Industries

Working in often challenging conditions across high-risk outdoor operations including forestry, emergency services, mining, rail, and utilities, our consolidated weather services ensure full situational awareness for you and your team.

DTN APAC serves fire-prone outdoor industries, delivering trusted weather data and severe weather alerting to maintain safety, protect your assets and underpin your operational planning.

Reinforce your Prevention, Preparedness, Response and Recovery (PPRR) efforts with our tailored services.

Prevention: Utilise our seasonal outlooks and daily forecasting to identify and implement prevention measures. Understand the climate risks affecting your operations. Calculate optimal timing for maintenance activities, vegetation management, and scheduled shutdowns.

Preparedness: Gain understanding of bushfire risk in the days, weeks and months leading up to peak fire season. Use DTN APAC’s seasonal outlooks and 14-day forecasting to plan workforce deployment, equipment positioning, and preventative operations such as controlled burns or asset maintenance.

Response: We deliver fire danger forecasts and provide nowcasting and forecasting of severe weather events, including thunderstorm/lightning detection and alerting, to give you full situational awareness of emergency conditions likely to impact your operations and infrastructure.

Recovery: Assess the weather risks affecting post-incident recovery and restoration processes. Utilise post-event analysis reports to support insurance claims, evaluate operational response effectiveness, and inform future risk management strategies.

We work to bring you full situational awareness so you can mitigate risk, ensure workforce safety, and maintain operational continuity across your outdoor assets.

Learn more about our large range of industry leading products and services or email us at sales.apac@dtn.com

See our Case Study on how Tasmania Fire Service (TFS) improved lightning detection and continued optimising preparations for challenging fire seasons ahead with DTN APAC’s full suite of solutions.

The post Heightened bushfire risk during the 2025-26 summer for WA, Victoria and NSW in latest AFAC Outlook appeared first on DTN APAC.

What is La Niña?

La Niña is one phase of a Pacific Ocean phenomenon called the El Niño–Southern Oscillation (ENSO). The other phases of ENSO are El Niño and neutral.

When La Niña is occurring, abnormally cool water lies near the surface of the central and eastern tropical Pacific Ocean and warmer than normal water sits in the western tropical Pacific. This sea surface temperature pattern is associated with changes in the overlying atmosphere, with easterly trade winds typically becoming stronger and blowing extra moisture towards the western side of the Pacific Ocean.

Image: Typical oceanic and atmospheric responses to La Niña. Source: Weatherzone.

What does La Niña mean for Australia’s businesses?

La Niña can have a strong influence on Australia’s weather. While El Niño’s weather impacts are mostly felt during winter and spring, La Niña can have a noticeable effect on Australian weather in summer.

Australia typically sees above average rain over northern and eastern parts of the country when La Niña is in place during summer. Eastern Australia’s mean summer rainfall is about 20% higher during La Niña, with the east coast typically seeing a stronger rainfall response to La Niña in summer than it does in winter or spring.

Daytime temperatures can also be suppressed over eastern and northern Australia when La Niña occurs in summer, which is associated with enhanced cloud cover over these parts of the country.

Tropical cyclone activity can also be amplified in the Australian region when La Niña is occurring.

The maps below show the average rainfall and maximum temperature changes observed across Australia from eight to nine past La Niña events combined.

Image: Average summer rainfall deciles under the influence of La Niña. The green and blue shading shows where summer rainfall is typically above average during La Niña. Source: Bureau of Meteorology.

Image: Average summer maximum temperature deciles under the influence of La Niña. The blue shading shows where summer days are typically cooler than average during La Niña. Source: Bureau of Meteorology.

It is important to note that no two La Niña events are the same and other competing climate drivers, including the Indian Ocean Dipole (IOD) and Southern Annular Mode (SAM), can reinforce or counteract La Niña’s influence.

La Niña underway

The Bureau of Meteorology declared on Thursday, November 27, that La Niña is underway. This declaration was not a signal that La Niña is suddenly occurring, but recognition that it has been in place for the past couple of months.

The Bureau of Meteorology’s criteria for declaring La Niña are mostly retrospective, meaning La Niña conditions need to have been present in both the ocean and atmosphere for an extended period before they will declare it.

The Bureau noted that “observations in the tropical Pacific Ocean have been consistent with La Niña conditions since early October.”

“The Bureau’s model currently predicts that tropical Pacific Ocean temperatures are likely to remain at La Niña levels until early 2026 before returning to neutral. This timing aligns with most international models assessed.”

What can Australian businesses expect from this La Niña?

With Australia entering summer under the influence of La Niña, many industries might be expecting to see above average rain and cooler than average days in the coming months, particularly in the country’s north and east.

However, the latest long-range outlooks from the Bureau paint a different picture, predicting near or below average rain and abnormally warm days for much of the country this summer.

Image: Chance of exceeding the median rainfall this summer. Source: Bureau of Meteorology.

Image: Chance of exceeding the median maximum temperature this summer. Source: Bureau of Meteorology.

One of the reasons for the warm and dry summer outlook, despite La Niña, is the ongoing influence of a negative Southern Annular Mode (SAM) in the Southern Hemisphere. This negative SAM has been in place since early October in response to rare episodes of Sudden Stratospheric Warning above Antarctica during mid to late spring.

A negative SAM during late spring and summer enhances westerly winds over Australia, which can counteract the influence of La Nina’s strengthened easterly trade winds. The current negative SAM phase has indeed been hindering La Niña’s influence on Australian weather in recent months, and this influence may linger into early summer.

Some international long-range forecast models do show signs of La Niña starting to have more influence on Australian rainfall in the coming weeks. This suggests that a breakdown of the negative SAM may allow La Niña’s influence to emerge more clearly into late December or January.

Image: Forecast monthly precipitation anomaly for Australia during December, according to the ECMWF SEAS5 model. Credit: DTN APAC.

The outlook for this summer is currently tricky to pin down due to the competing influences of La Niña and the SAM, and uncertainty regarding the future development of the SAM into December.

DTN meteorologists will be keeping a close eye on the primary climate drivers around Australia in the coming weeks to see how this situation evolves heading into summer.

How DTN APAC can help

The shifting climate is bringing increased complexity and greater risks to businesses worldwide. We are here for you, delivering trusted weather solutions to optimize your operations and profitability.

DTN APAC is a diverse team, with global forecasting, product development and analytics expertise. Couple this with extensive industry experience spanning Aviation to Energy, and we are primed to assist you in strengthening your response to weather impact.

We work hard to identify your operational pressures and tailor our services and products to meet your needs. Concise communication, giving you full situational awareness exactly when you need it, is our focus. We want to reduce weather risk in your operations, every day.

We deliver clear and comprehensive weather data that you can’t get anywhere else, personalised risk assessments and briefings to you and your team, so that your critical decisions can be made with confidence.

We are available 365 days a year, so you always have the timely guidance you require, especially when severe conditions hit.

You have our insights to rely on to see you through complex situations, minimising potential loss of profit and maximising the safety of your staff and assets.

Learn more about our large range of industry leading products and services or email us at sales.apac@dtn.com

Thumbnail image source: iStock / da-kuk.

The post Bureau of Meteorology declares La Niña days out from summer – what does this mean for Australian businesses? appeared first on DTN APAC.

Over 75,000 customers across southeast Queensland remain without power on Tuesday, after a peak of around 161,000 following the relatively brief, but intense severe thunderstorms complex that crossed the region on Monday afternoon. Damage to power utility networks and rescue efforts for residents was worse than those inflicted by Cyclone Alfred in March for some areas.

An outbreak of thunderstorms formed over far northeastern New South Wales on Monday and rapidly crossed the border, impacting densely populated areas along the coast and nearby hinterland and ranges from the Gold Coast to Bundaberg, including the Brisbane Metropolitan and Sunshine Coast regions.

Image: Eight-hour loop showing radar and satellite imagery from 2pm to 10pm AEST in southeast Queensland and far northeast NSW on Monday, 24 November, 2025.

Some of the largest hailstones observed included:

• 14cm hailstones near Chandler around 3:00pm
• 11cm hailstones at Manly, Ferny Hills and Alexandra Hills around 3:30pm
• 9cm hailstones at Bunya around 3.24pm
• 9cm hailstones at Coombabah, Gold Coast, at 2:10pm

Some of the noteworthy rainfall totals (all of which fell in a brief period of around an hour or less) included:

• 79mm at Moreton Island
• 69mm at Upper Rous River/Hopkins Creek (on the NSW side of the border, just south of Lamington NP)
• 56mm at Hervey Bay
• 40.6mm at Maryborough
• 34.8mm at Tewantin
• 31.6mm at Brisbane Airport
• 29.4mm at Brisbane

Wind gusts exceeding 100 km/h were also reported during the storms in southeast Queensland, including at Brisbane Airport and on the Sunshine Coast.

The DTN Total Lightning Network reported over a million lightning strikes detected within 400 km of Brisbane on Monday, November 24, 2025, nearly 200,000 of which were ground strikes.

Flying tree branches, roofs and debris from these intense thunderstorms downed over 600 powerlines, resulting in over 161,000 energy customers without power on Monday. Power utility companies and contractors are hard at work on the recovery effort, but power restoration and clean up could still take days to be completed.

How did the storms form?

The three main ingredients for thunderstorms are:

• Instability
• Moisture
• Trigger

Atmospheric instability was abundant over southeast Queensland and northeast NSW on Monday due to warm air near the surface and much cooler, drier air aloft. This instability provided the lift required to build large thunderstorm clouds stretching thousands of metres into the sky.

There was also plenty of moisture available in the lower and middle levels of the atmosphere, providing ample fuel for storm clouds to become loaded with rain and hail.

Two significant triggers for storms were also present on Monday. The first being a ‘dry line’ sitting over southeast Queensland and northeast NSW, which is a zone where moisture-laden air to the east clashes with drier air to the west. The second trigger for storms was a southeasterly wind change moving towards the north throughout the afternoon and evening.

One additional ingredient that helped make Monday’s storms particularly dangerous was wind shear, which refers to the change in wind speed and direction with height. Strong wind shear over southeast Queensland and northeast NSW helped create rotation in thunderstorms, increasing the likelihood of supercells, which are the most violent and dangerous type of thunderstorm.

Why was the hail so large?

Image: Hailstones the size of apples fell in The Gap, Brisbane, on November 24, 2025. Source: Nick Gilpin (@nickgilpin) on Threads.

Hail forms when raindrops are carried high into the sky by a thunderstorm’s updraft. The hail grows larger when it collides with supercooled water droplets high in the storm cloud, which freeze onto the surface of the hailstone and make it grow.

Stronger thunderstorms have powerful updrafts that cause hailstones to rise and fall over and over, accumulating new layers of ice each time they lift into the cold upper-levels of the storm (that’s why you often see layers on a large hailstone resembling the rings inside an onion).

As mentioned above, all of the elements were in place for the development of severe thunderstorms, which meant the atmosphere was like a natural laboratory for the creation of giant hailstones.

What next for Brisbane and Southeast Queensland weather?

Afternoon or evening showers and thunderstorms are possible over the next three days from this Tuesday through to Thursday. The storms may be severe.

Days will be hot, sticky and uncomfortable right across southeast Queensland, with maximums in the low-to-mid thirties across the region. Inland temperatures will be a few degrees higher than those along the coast.

How DTN APAC is helping remote mining, transport, fire services and agricultural industries with advanced weather intelligence, remote sensing and now-casting solutions during the severe weather season

Australia is a vast country with densely populated coastal areas across the south and east, and millions of square kilometres of sparsely populated and rich in resources elsewhere. Typical radar coverage extends to a radius of about 200km, however mountains, trees and towers can restrict this optimal coverage range. Even with over 60 radar sites operating across Australia, vast expanses of the outback and WA remain outside of this traditional radar coverage, as seen in the left image below.

Image: Comparison of traditional radar coverage and detected rainfall (left), and DTN’s Oracle and TLN (right), across Australia at 1am AEST on Tuesday, September 9, 2025.

The image on the right shows DTN’s Oracle rainfall and Total Lightning Network detecting a vast area of rain and thunderstorms that would have been missed by traditional detection methods.

DTN Oracle

The post Giant hail and intense thunderstorms leaves 161,000 customers without power across southeast Queensland appeared first on DTN APAC.