The base cloud/rain field relaxes to a static pattern under fixed forcing, so it looked
frozen. stepWeather now also runs a population of drifting WeatherSystem agents (world
objects, not cells; transient/not saved; separate sWeatherRng seeded from cfg.seed so
tectonic determinism is intact): spawn over warm tropical ocean (5-25 deg, SST gate) or a
mid-latitude ocean low (capped at weatherSystemMax); move along the steering wind (sWind at
the nearest cell) plus a poleward recurve at weatherSystemSpeed; intensify over warm sea,
decay and cull over land/cold; and stamp a Gaussian cloud/rain shield onto the grid so cloud
clusters travel and dissipate behind them. A tropical system past weatherHurricaneStr is a
hurricane/typhoon.
Render: an animated cyclonic spiral marker per system (red + eye for cyclones, blue lows;
spins with liveTime by hemisphere) in 3D + 2D, HUD system/cyclone counts, and a basin-named
storm list in the Sky & tides panel -- all under K. New weather* storm knobs. test_weather.cpp
adds: systems spawn, move between steps, thicken cloud, RNG isolation, determinism. All five
suites pass; GUI build clean. Docs updated.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>