Weather tracking isn’t just about checking if you’ll need an umbrella. It’s a puzzle, a challenge, a skill to master. For weather enthusiasts, radar maps hold the key to understanding how storms behave and what a thunderstorm may consist of.
Whether you’re tracking an incoming thunderstorm or sharpening your forecasting skills, learning to recognize different thunderstorm types on radar can take your weather-watching to the next level.
Why Storm Structure Matters
Not all thunderstorms are created equal. Some storms drop light rain; others unleash violent tornadoes and flash floods. By understanding storm structure, you can anticipate what a system might do next, whether it’s intensifying, weakening, or posing a more severe threat.
Thunderstorms typically fall into a few key categories according to structure: single-cell thunderstorms, multi-cell clusters, squall lines, and supercells. Let’s break them down and learn how to spot them on radar.
1. Pop-Up Thunderstorms (Single-Cell Storms)
Also called “pulse thunderstorms,” these small, short-lived storms form due to daytime heating and moisture in the atmosphere. Single-cell storms may typically last 30–60 minutes and don’t organize into larger systems.
How they look on radar:
Isolated cells with a circular or slightly oval shape
Relatively weak reflectivity (light to moderate shades on radar)
Sudden appearance and dissipation without much movement
Why they matter:
Pop-up storms are highly localized: one neighborhood might see heavy rain while the next stays dry. They rarely produce severe weather but can lead to brief heavy downpours and lightning. These storms can be frustrating for forecasters because they develop quickly and dissipate just as fast, making it challenging to predict exact locations of impact.
Forecasting tip:
Since these storms form due to daytime heating, they are most common in the afternoon and early evening. If prevailing atmospheric conditions are right (high humidity and warm surface temperatures), watch for these to develop and fade quickly.
2. Multi-Cell Thunderstorms (Clusters & Squall Lines)
Multi-cell storms are a step up in complexity. They consist of multiple storm cells in various stages of development, making them stronger and more long-lived than single-cell storms. Multicell storms can produce wind gusts over 50 mph and rain rates exceeding 1 inch per hour.
Multi-Cell Clusters
Groups of individual storms moving together, forming a loose cluster.
Often found in warm, humid conditions, producing heavy rain, lightning, and gusty winds.
Can persist for many hours and cover larger areas than pop-up storms.
Source: National Weather Service
Squall Lines (A Type of Multi-Cell Lines)
A long, narrow line of storms often stretching for hundreds of miles.
Capable of producing damaging straight-line winds (sometimes over 60 mph) and heavy rainfall.
Frequently associated with advancing cold fronts.
How they look on radar:
- Multicell clusters appear as a scattered group of storm cells, growing and dying out over time.
- Squall lines form a solid, well-organized line of strong reflectivity (bright colors on radar), often bowing outward in a bow echo pattern.
Why they matter:
Squall lines are notorious for strong gust fronts ahead of the main storm. These winds can down trees, damage structures, and cause power outages. Some squall lines also produce embedded supercells, increasing the risk of tornadoes.
Forecasting tip:
If you see a bow echo forming on radar, be prepared for potentially damaging winds in its path. Stronger squall lines can maintain intensity for several hours and cover vast areas, e.g. spread across an entire state.
3. Supercell Thunderstorms: The Kings of Severe Weather
Supercells are the most organized and dangerous type of thunderstorm. They contain a rotating updraft (called a mesocyclone) and have the potential to produce tornadoes, large hail, and extreme winds.
How they look on radar:
A classic supercell is a large, isolated storm with a distinctive hook echo (a curled shape) on radar, indicating rotation.
Strong core with high reflectivity (deep red and purple colors) in the main storm area.
Sometimes accompanied by a bounded weak echo region (BWER)—a radar signature showing strong updrafts.
Why they matter:
Supercells are responsible for some of the most extreme weather events, including strong tornadoes (EF2 and higher), baseball-sized hail, and destructive winds. These severe thunderstorms may last for hours, which makes them particularly dangerous.
Forecasting tip:
If you spot a hook echo and strong rotation on velocity radar, take it seriously. These storms can evolve rapidly into tornadic supercells. Supercells often form in highly unstable environments, so if conditions are favorable, remain alert for warnings and watch their development closely.
Radar Challenge: Spot the Type of Thunderstorm
Now that you know the basics, put your skills to the test! Next time a storm is forming, check RainViewer’s radar and try to classify it. Is it an isolated pop-up storm? A squall line? Maybe even a supercell? By tracking storm evolution over time, you’ll start to recognize patterns and sharpen your forecasting abilities.
Interactive Learning: Decode a Real Radar Image
Check your radar now - do you see a bow echo forming? With practice, you’ll be able to interpret storm structures with confidence. making your weather tracking more engaging, interactive, and insightful. Happy forecasting!
Stay Ahead of the Storm with Rain Viewer
Rain Viewer gives you real-time radar updates, making it easy to track storms as they develop. Whether you’re watching for severe weather or just love the thrill of forecasting, our app is your go-to tool for accurate, engaging weather tracking.
Download Rain Viewer and start decoding storms today!
