8  Animation & Archive Replay

Radar is most useful in motion. NeoWeatherwall loops recent frames for live monitoring and can replay historical events along a recorded chase route.

8.1 Live animation

By default the app loads roughly the last hour of radar and loops it. Use the playback transport:

  • Step Backward: back one frame (one volume scan).
  • Play / Pause: start/stop the loop.
  • Step Forward: forward one frame.
  • Timeline scrubber: drag to seek to any frame.
  • Playback speed: adjust how fast the loop runs.

Screenshot of the radar playback transport controls and timeline scrubber

The playback transport and timeline scrubber.
NoteCompact layouts

On a compact iPhone screen the single-frame step buttons may be hidden to save space. Use play/pause and the scrubber instead.

Looping is how you judge trends: is a cell intensifying, is a couplet tightening, are storms training over the same area? A single frame can’t tell you that.

8.2 Archive replay

NeoWeatherwall can replay a past event using a recorded GPS track:

Screenshot of the GPS log tools for loading a chase log

The GPS Log Tools used to load a chase log for archive replay.
  1. Load a GPS log: import a chase log in .gpl (WeatherWall legacy) or .gpx (standard GPS exchange) format via Settings > Debug > GPS Log Tools.
  2. The app draws the GPS Log Trail and fetches historical radar covering the route’s time span from AWS.
  3. Step or play through the archived volume scans frame by frame, watching your position move along the trail in sync with the radar.

This is built for post-event review: replay a chase to study how the storm evolved and how your positioning lined up with the radar.

8.3 Level 2 vs. Level 3 in the archive

During archive replay you can opt into Level 2 (Archive II) data instead of Level 3 products:

  • Level 2 provides higher-resolution base moments (reflectivity, velocity) but means larger downloads.
  • With Level 2 enabled, the app can dealias velocity (resolving the aliasing ambiguities described in Artifacts & Limitations) and derive azimuthal shear from the base velocity.

Enable this in the archive/Level 2 settings when you want the cleanest possible velocity analysis of a past event and don’t mind the extra bandwidth.

8.4 Activity overlays during replay

While replaying, the map shows your GPS Log Position marker and a real-time Chase Trail so you can correlate where you were with what the radar showed at that moment.