Severe Thunderstorm Warnings in Australia: What They Mean, Updated November 7, 2026

Information verified: November 7, 2026, at 09:09 UTC.

A severe thunderstorm warning in Australia means the Bureau of Meteorology has identified a storm that is occurring, likely to occur, or reported, and that may bring dangerous conditions to the warning area. Those conditions can include damaging wind gusts, large hail, flash flooding, or a tornado. If your location is affected, take the named hazards seriously and follow emergency service advice.

A warning does not mean every place in the outlined area will experience every hazard. Thunderstorms can change quickly and affect small areas, so the warning may be updated as the situation develops. This explainer describes the warning system; it is not a report that a particular warning is currently in force.

Destaques

• One qualifying hazard is enough for a thunderstorm to be classified as severe.
• Large hail means hail at least 2 centimeters across; damaging wind gusts reach at least 90 km/h.
• Heavy rain can cause flash flooding, and tornadoes are also included among the severe hazards.
• Move to safe shelter, avoid floodwater, and follow the latest advice for your location.

What makes a thunderstorm severe in Australia?

The Bureau classifies a thunderstorm as severe when it produces at least one of four hazards: hail 2 centimeters or larger in diameter, wind gusts of at least 90 km/h, a tornado, or heavy rainfall that may lead to flash flooding. A storm does not need to produce all four.

The Bureau issues a warning when a severe thunderstorm is occurring, likely to occur, or reported; when the relevant hazards are expected in the warning area; or when existing thunderstorms are likely to become severe. Its thunderstorm guide explains the criteria and how storms develop.

These thresholds describe the potential for serious impacts. Hail can injure people and damage roofs or vehicles. Strong gusts can bring down branches and power lines or turn loose objects into hazards. Intense rain can overwhelm drains and rapidly flood roads. A tornado can cause concentrated destruction along its path.

What does a severe thunderstorm warning tell you?

Read the warning for its stated hazards and affected area. Depending on the product, it may describe where storms have been detected, where they are expected to move, and which locations could be affected. Use that information to decide what you need to protect and where you can shelter safely.

The outlined area is an estimate of the threat, not a promise that a storm will strike every address inside it. Nor should a boundary be treated as a protective barrier: storm development and movement can be uncertain. Check for updates and pay attention to changing conditions and instructions from emergency services.

A general forecast mentioning possible thunderstorms is an earlier indication that storms may develop. A severe thunderstorm warning is more specific: it is issued when a severe storm or its qualifying hazards are occurring or expected under the Bureau's warning criteria. Neither message guarantees the precise outcome at an individual property.

What should you do during a severe thunderstorm warning?

Act on the specific warning and the advice of your state or territory emergency service. If conditions allow you to prepare safely before the storm arrives, secure loose outdoor items, bring children and pets indoors, and move vehicles under secure cover away from trees and power lines.

• Find shelter: Stay indoors, away from windows, doors, and skylights. Avoid unnecessary outdoor activity and travel.
• Avoid floodwater: Never drive, ride, or walk through it. Water can rise quickly and hide damaged roads or drains.
• If driving: Slow down and, when safe, pull over in a sheltered location away from trees, power lines, and low-lying areas.
• After the storm: Stay clear of fallen power lines, damaged buildings, and debris. Hazards can remain after the rain stops.

These steps are consistent with NSW State Emergency Service storm guidance. In a life-threatening emergency, call Triple Zero (000). In New South Wales, call the SES on 132 500 for emergency assistance during a flood or storm.

What is a very dangerous thunderstorm?

The Bureau uses the term “very dangerous” for higher-end severe phenomena. Its warning product guide includes giant hail of at least 5 centimeters in diameter, destructive wind gusts of at least 125 km/h, tornadoes, and intense rainfall that may lead to dangerous, life-threatening flash flooding. The exact hazards named in an individual warning matter: prepare for those identified and follow the accompanying safety advice. See the Bureau's warning products guide for the definitions.

Can a thunderstorm be dangerous without a severe warning?

Yes. All thunderstorms produce lightning, which is dangerous even when the storm does not meet the severe criteria. Heavy rain, gusty conditions, and local hazards can also disrupt travel and outdoor activities. Seek shelter when a thunderstorm approaches rather than waiting for a severe warning to justify taking precautions.

Storms can develop and dissipate quickly, so the next step is to keep monitoring official information while the threat continues. The Bureau's warning services guide explains the different warning types. Follow local emergency service instructions, particularly if a separate flood or evacuation warning is issued.

Frequently asked questions

Does a warning mean a tornado is coming?

No. A tornado is one possible severe thunderstorm hazard, but a warning may be issued for hail, damaging winds, or heavy rain instead. Read the warning to see which hazards are expected.

Does a severe warning mean my home will be hit?

Not necessarily. The warning covers an area at risk, and the most damaging conditions may affect only part of it. Prepare for the stated hazards and watch for updates.

Is lightning included in the severe criteria?

Lightning alone is not one of the four criteria used to classify a thunderstorm as severe. It is still dangerous, so seek safe shelter whenever a thunderstorm approaches.