Understanding Radar Types
The Live tab has 9 different radar and data layers you can toggle on. Here's what each one actually shows you and why it matters.
Standard Radar
Your basic weather radar. Shows where rain, snow, and storms are happening right now.
In plain English: Think of this as the standard TV weather map. Green means light rain, yellow means heavier, red means intense. You can scrub through time to see where the storm came from and where it's going.
💡 This is always free and the best starting point for tracking storms.
HD Radar
MRMS (Multi-Radar Multi-Sensor) high-resolution composite radar — sharper and more detailed than standard.
In plain English: Like upgrading from regular TV to 4K. Storm cells are sharper, boundaries are clearer. This merges data from multiple radar sites for a more complete picture.
💡 Great for zooming into your area and seeing exactly where storm boundaries are.
Base Reflectivity
Raw NEXRAD single-site radar data at the lowest tilt angle — the most unfiltered view.
In plain English: Standard radar merges many radars together. Base Reflectivity shows you one specific radar's view at its lowest angle. It's raw and unfiltered — the closest look at what's happening near the ground.
💡 Use when you want the most detailed, unfiltered view near the ground — especially near the radar site.
Velocity
Doppler velocity data showing wind direction relative to the radar — critical for rotation detection.
In plain English: Green means wind blowing toward the radar, red means away. When you see bright green and bright red right next to each other (a "couplet"), that's rotation — and that's what forecasters use to issue tornado warnings.
💡 Look for tight "couplets" of green and red — that's the signature of rotation that can indicate a tornado.
Forecast Radar
HRRR (High-Resolution Rapid Refresh) model — shows predicted radar for the next few hours.
In plain English: This isn't current radar — it's the computer model's best guess at where storms will be up to about 3 hours from now. Think of it as a weather crystal ball.
💡 Use this to see if storms are heading your way before they actually get there.
Storm Cells
Radar-detected storm attributes — hail probability, rotation, and tornado vortex signatures.
In plain English: Colored dots on the map, each representing a radar-detected storm. Blue = regular. Yellow = hail. Orange = rotation detected. Red = tornado vortex signature (TVS). The color tells you what the radar sees in that storm.
💡 If you see a red dot near your location, take it seriously — red means the radar has detected strong rotation consistent with a tornado.
Echo Tops
Height of the highest radar returns in a storm — shows how tall storms are.
In plain English: Taller storms are usually stronger storms. If a storm reaches 40,000+ feet, it's a beast. Echo Tops gives you a quick visual of storm intensity at a glance — no interpretation needed.
💡 Look for sudden increases in echo tops — that can indicate a storm is rapidly strengthening.
Satellite
GOES East satellite imagery — Infrared, Visible, and Water Vapor channels.
In plain English: See the actual clouds from space. Infrared shows cold cloud tops (brighter = colder = taller). Visible is like a photo from space (daytime only). Water Vapor shows where moisture is flowing in the atmosphere.
💡 Infrared works day and night. Switch to Visible during daytime for the most realistic view of storm structure.
Precipitation
Accumulated precipitation over 1, 24, 48, or 72 hours.
In plain English: Instead of showing what's happening now, this shows totals — how much rain has actually fallen. Great for spotting flood-prone areas or seeing which spots got hammered.
💡 Check the 24-hour view after storms to see total rainfall amounts and identify flood risk areas.
Multi-Layer Mode
By default, you can only show one radar layer at a time. With Multi-Layer Mode, you can stack multiple layers on top of each other.
For example, overlay Storm Cells on top of HD Radar to see both the storm structure and the radar-detected attributes at the same time. Each layer has its own opacity slider so you can fine-tune the view.
Storm Cell Color Guide
Blue — Regular Storm
A radar-detected storm with no severe attributes.
Yellow — Hail Storm
Storm producing or likely producing hail.
Orange — Mesocyclone
Storm with detected rotation — a possible tornado producer.
Red — TVS (Tornado Vortex Signature)
Radar has detected strong rotation consistent with a tornado. Take cover.
