WeatherStory Radar · macOS

Volumetric 3D radar for the Mac.

Storms rendered as three-dimensional structure, built from every gate of raw NEXRAD Level II on your Mac’s GPU. GOES satellite, HRRR forecast and the national MRMS mosaic sit in the same workspace, read directly from NOAA’s public archives.

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Version 0.9.0-alpha · macOS 15.0+ · Apple Silicon & Intel · 179.6 MB

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Upton, NY (KOKX), 26 September, rotated in real time. Each surface is a fixed dBZ threshold; vertical exaggeration is set in the toolbar.

How it works

Raw data, rendered on your Mac

WeatherStory Radar downloads NEXRAD Level II, the MRMS national mosaic, GOES and VIIRS imagery and the HRRR forecast directly from NOAA’s public archives, then decodes and draws them on your Mac’s GPU. Nothing is pre-rendered on a server, so every view works from the underlying measurements.

  1. 01Storms in three dimensions
  2. 02Every gate of raw Level II
  3. 03The national picture at full resolution
  4. 04Satellite and forecast in one view
  5. 05One system, start to finish
  6. 06Severe weather, tracked

Storms in three dimensions

Reflectivity from a full Level II volume, drawn as solid surfaces at fixed dBZ thresholds. Rotate and tilt the storm, change the vertical exaggeration, and read the value and beam height of any gate under the cursor.

  • Surfaces at 18.3, 35 and 50 dBZ
  • Vertical exaggeration shown on screen
  • Nothing drawn above the highest scanned elevation
Volumetric 3D, low angleThe same KOKX volume, 26 Sep, brought from overhead down to a low viewing angle.
A wide overhead view of many three-dimensional storm cells rendered as translucent white, gold and red surfaces across a regional map.
Regional viewMany cells across a regional map. Gold marks 35 dBZ and red 50 dBZ.
The Storm 3D window showing reflectivity surfaces with a legend reading 18 dBZ, 35 dBZ and 50 dBZ.
The 3D windowEach surface has its own legend entry, with a height control.
Nested translucent reflectivity surfaces standing over a dark map of the mid-Atlantic, with county lines and city labels visible through them.
IsosurfacesSurfaces at 18.3, 35 and 50 dBZ over the mid-Atlantic. They end at the highest elevation the radar sampled.

Every gate of raw Level II

All 159 WSR-88D radars, decoded from raw Archive II on your Mac. Reflectivity, velocity, spectrum width, ZDR, correlation coefficient, KDP and storm-relative velocity at every tilt. Click any gate for its value and beam height (4/3-earth model).

  • 159 radars
  • Every tilt selectable
  • Value and beam height on click
Single-site Level IIMelbourne, FL (KMLB), 0.5° tilt, 19 Sep. Afternoon sea-breeze convection across central Florida. Tilt selector at right.

The national picture at full resolution

The MRMS composite covers the contiguous US at about 1 km: a 7000×3500 grid, drawn without downsampling. Surface observations, isobars, NWS warnings and SPC outlooks sit on the same map. See the color table guide.

  • ~1 km national grid, updated every ~2 min
  • About 13 h loops on a 32 GB Mac, up to 24 h on 64 GB
National viewContiguous US, 20 Sep, with storm-motion labels, NWS warnings, SPC outlooks and pressure centers.
Overnight national loop19:34Z 18 Sep to 02:54Z 19 Sep. Lightning in yellow.
The full CONUS radar mosaic with green and blue precipitation echoes across the United States on a near-black basemap.
MRMS compositeThe full national composite on a dark basemap.
The national radar mosaic across the eastern United States, overlaid with hundreds of amber surface-observation stations and green isobar contours.
Surface observationsThe eastern US with METAR stations and isobars over the mosaic.

Satellite and forecast in one view

GOES true color pan-sharpened to 500 m, clean infrared with NOAA’s published enhancement curve, and VIIRS passes at 375 m on their actual swath footprint, all under the radar. HRRR forecast reflectivity extends the loop hourly to +12 hours, with a marker at the current time.

  • GOES true color at 500 m
  • VIIRS at 375 m
  • HRRR to +12 h
GOES true color with radarGOES true color beneath the national radar mosaic, 26 Sep, across the day–night boundary. Tropical cyclones visible in the eastern Pacific.
A VIIRS satellite swath rendered as a tilted parallelogram of high-detail grayscale cloud imagery across the western United States.
VIIRS passA 375 m VIIRS swath over the western US, drawn on its actual footprint.

One system, start to finish

A coastal low off the Mid-Atlantic on 26 September, followed through one afternoon in a single workspace: satellite and radar together, then wind speed contours, then every layer at once.

IsotachsWind speed contours around the Mid-Atlantic coastal low, 26 Sep. The gold contour is 34 kt, tropical-storm force.
Satellite, radar and isobarsThe same low earlier in the loop, with all three layers together.
Full workspace15:14–22:22Z on 26 Sep, with radar, isobars, isotachs and the layers panel.

Severe weather, tracked

Storm motion is computed by cross-correlating consecutive scans; each tracked cell is labeled with its speed and scan time, and arrow length is proportional to speed. NWS warning polygons, SPC outlooks and lightning draw on the same map.

  • Motion from consecutive scans
  • NWS warnings and SPC outlooks
  • Lightning
Storm trackingFlorida, 20 Sep. Each tracked cell is labeled with speed and scan time.
Lightning and warningsNebraska Panhandle, 18–19 Sep. Lightning within a warning polygon, with storm-motion vectors.
Upstate South Carolina18–19 Sep, full-screen mode. A line of storms moving through warning polygons.
Carolinas18 Sep, afternoon through evening, as scattered cells merge into a widespread rain area.

Performance

Full resolution, every frame

Rendering is written directly in Metal. Radar, satellite and model data stay on the GPU and are drawn at full resolution every frame, so panning, zooming and looping don’t require downsampling the data first.

120 Hz

Up to 120 frames per second on ProMotion displays, with triple buffering.

24.5M

Cells in the 7000×3500 national composite, all drawn in every frame.

~4 ms

To render a 461×461×37-sample 3D volume, measured with GPU timestamps.

4× MSAA

Anti-aliased map lines, resolved in on-chip tile memory on Apple silicon.

Data

Where the data comes from

All data comes directly from public archives. No account, API key or intermediary server.

SourceWhat it providesUpdates
NEXRAD Level IIAll 159 WSR-88D radars, raw Archive IIEvery 4–6 min
MRMSNational composite, 7000×3500 at ~1 kmEvery ~2 min
GOES-19 ABITrue color at 500 m, clean IR, cloud-top height5 min / 1 min meso
VIIRS375 m detail passesA few daily
HRRRForecast reflectivity, pressure, temperature, windHourly
METAR · NWS · SPCSurface observations, warnings, outlooks5 min / as issued

The app is signed with an Apple Developer ID and notarized, and updates are delivered over a cryptographically signed feed. Each release publishes its SHA-256 so you can verify the download.

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Free trial

14 days with every feature enabled. No card required. For the best evaluation, start it when active weather is expected.

Download 0.9.0-alpha

macOS 15.0 or later · Apple Silicon or Intel · 179.6 MB · published 2026-09-12 · notarized by Apple

Licence

$99 once, including a year of updates. The app keeps working after that year; renewal only buys newer versions. No data subscription: every source is a free public archive.

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