Live weather radar, from the national picture to the nearest site

National MRMS radar gives the broad view

Multi-Radar Multi-Sensor data combines information from many radars and related sources into a consistent national mosaic. It is useful for seeing the shape and movement of weather systems across regions without jumping from one radar site to another.

The mosaic is still a processed radar product. RR Weather shows its frame time and loading state because network delay, upstream processing, and browser rendering can separate “now” on the timeline from the actual source time.

High-Res Radar reveals more storm detail

The High-Res Radar source uses Level II data from an individual NEXRAD radar near the selected area. It can show finer storm structure and several radar products, but distance from the site, beam height, terrain, and the chosen elevation angle all affect what the radar can see.

Reflectivity

Shows the strength of returned energy. Rain, hail, snow, insects, ground clutter, and other targets can all contribute to a return.

Velocity

Shows motion toward or away from the radar along the beam. It does not directly show the full wind speed or direction at the ground.

Correlation coefficient

Compares how similarly radar pulses behave. It can help distinguish types of targets, but interpretation depends on the full storm context.

Differential reflectivity

Compares horizontal and vertical returns to provide clues about target shape and orientation.

Observed radar and Future Radar answer different questions

The National and High-Res sources begin with radar observations: a processed MRMS mosaic for the national view and an individual NEXRAD scan for the local view. Their frame times tell you when the source data was collected or assembled; they do not make the image a measurement of rain at the ground.

Future Radar displays explicitly labeled forecast or nowcast frames. Depending on lead time and source availability, it can use an experimental MRMS optical-flow extrapolation, blend that radar trend with NOAA HRRR guidance, or display NOAA HRRR composite reflectivity directly. RR Weather labels the method and valid time so every future frame stays distinct from the observed frames that precede it. A future frame is an estimate—not an observation, a guaranteed storm track, or an official warning.

GOES satellite imagery adds cloud context

The Radar view can overlay merged GOES East and West imagery. GeoColor combines a daytime color-like view with a different nighttime presentation, while Infrared uses longwave imagery to show cloud-top temperature patterns by day or night.

Satellite imagery shows clouds and other features, not a direct map of surface rain. Check its source time separately, and use it alongside radar rather than treating one layer as confirmation of the other. The official weather source register links to the upstream NOAA products.

Map layers add context without changing the radar

Place labels, the selected-location marker, official NWS hazard polygons, and optional severe-weather context remain separate from the radar image. Keeping those layers above radar makes their source and meaning easier to follow.

A polygon tells you where an official product applies; a radar color shows returned energy. One should never be read as the other.

How to read a radar loop without outrunning the data

1. Find the observed-to-forecast boundary. Observed frames carry source times; Future Radar frames carry forecast valid times.
2. Watch several frames. A consistent trend is more useful than one jump, missing frame, or brief echo.
3. Check the source and product. A national mosaic, a local radar scan, reflectivity, and velocity answer different questions.
4. Allow for age and geometry. Processing delay, distance, beam height, and terrain can change what the loop appears to show.
5. Check official alerts. Radar interpretation never replaces a warning or instruction from authorities.