📡 How to Read Doppler Radar – A Beginner's Guide

Reflectivity: What the Colors Mean

Reflectivity radar measures how much energy bounces back from precipitation, and it is shown in decibels (dBZ). Higher dBZ means heavier precipitation or larger particles. The scale used on this site runs from light greens for gentle rain up to purples and whites for the most intense cores. Use this table as your quick reference:

Colors alone never tell the whole story. A bright core over a city means heavy rain or hail is likely there, but only a warning tells you whether it is officially dangerous. Always pair what you see on radar with the live warnings feed above.

See the live radar reflectivity map with the full dBZ scale, what reflectivity is for, and how the radar image is made.

To read the same map as how hard it is raining, see the live rain rate radar map with the mm/h scale and how radar estimates rainfall.

Velocity: How Radar Sees Wind

Doppler radar also measures motion. Its velocity product colors wind moving toward the radar differently from wind moving away, usually green for inbound and red for outbound. When green and red sit tightly together, the air is rotating, and that rotation signature is what forecasters watch for tornado potential. Broad, smooth velocity patterns show the general wind flow, while a tight couplet is the pattern that matters most for severe weather.

Using the Loop Controls

• Press play to animate the loop and watch how storms move, grow, or fade over time. Direction of movement tells you where a storm is headed next.
• Pause on the latest frame for the current picture, and step back through earlier frames to see whether a storm is strengthening or weakening.
• Zoom into your area for street-level detail, and zoom out to see the larger system driving your local weather.
• Compare the radar with the warnings feed: warned storms are outlined by the National Weather Service, and the warning text names the hazard and the areas affected.

Common Radar Patterns to Recognize

• Scattered green blobs: light, spotty rain showers with no severe threat.
• A solid line of storms: a squall line, which can bring strong winds along its whole length.
• A bow shape in a line: a bow echo, often linked to damaging straight-line winds near the bulge.
• A hook shape on the end of a storm: a hook echo, a classic sign of a rotating supercell that may produce a tornado.
• A bright band that stays in one place: training storms, which can cause flash flooding even without a severe warning.