Rain and storms

First rain after a dry spell: why roads get slippery and how to drive

The first rain can sharply reduce grip. Learn what happens on the road, how to anticipate it and what to do if aquaplaning begins.

Rainfall intensity and accumulation: how to interpret each figure

Understand mm/h and accumulated rainfall, why they describe different hazards, and how to read both before travelling or planning outdoor activities.

Why do so many thunderstorms form in the afternoon?

Daytime heating helps trigger convection, but it is only one part of the process. Moisture, instability and lift must come together for afternoon storms to develop.

Funnel cloud or tornado: how to tell the difference and stay safe

A funnel cloud does not always reach the ground, but it should be treated cautiously. Learn which signs confirm a tornado and what to do.

Arcus cloud: what a dark shelf ahead of a storm really means

How to recognise an arcus or shelf cloud, why it forms on a gust front and what precautions to take as it approaches.

Thunderstorm anvil: how it forms and what it reveals

The flattened top of a cumulonimbus identifies a mature storm, but it does not by itself prove severity or show exactly where the storm will move.

Dry thunderstorms: why lightning can occur with little rain

A dry thunderstorm can produce lightning and strong outflow winds even when little rain reaches the ground. Learn how it forms and how to stay safe.

Squall lines: what they are and why they can bring destructive winds

A squall line is an organised band of thunderstorms that can travel far and concentrate strong wind, lightning and heavy rain.

Cut-off low: what a DANA is, how it forms and why not all heavy rain is one

DANA is the Spanish term for an isolated upper-level depression, not a synonym for a storm or flood. Learn how it forms and what creates real risk.

Downburst and gust front: what they are and how to stay safe

Learn how downbursts and gust fronts create sudden severe winds, what warning signs may appear and how to respond safely.

How far away is a thunderstorm? Calculate it from lightning and thunder

Counting the seconds between lightning and thunder can estimate the distance to one discharge, but it never means it is safe to remain outdoors.

Cumulonimbus: how to recognise a thunderstorm cloud and understand its hazards

Learn to identify cumulonimbus by its rapid vertical growth, dark base and anvil, and when those signs mean it is time to seek shelter.

Hail: how it forms, what determines its size and how to stay safe

Hail grows inside powerful thunderstorms, but not every storm produces it and impacts can be very local. Learn how to read the risk and act safely.

Dry ravines and gullies: why they can flood when it is not raining where you are

Rain kilometres upstream can turn a dry channel into a fast flood. Learn how to read the catchment, warning signs and official information.