How We Animated GraphCast’s Global Weather Predictions in Real-Time on an iPhone Using Cesium & WebGL Shaders

Imagine taking Google DeepMind’s GraphCast—a state-of-the-art AI weather model—and visualizing its global, high-resolution predictions smoothly on a mobile browser. Sounds like a fast track to melting your iPhone's GPU, right? Usually, processing and rendering massive multi-dimensional spatial data (like global wind patterns, temperature, and pressure across multiple time steps) requires hefty desktop hardware. When you try to render that kind of heavy data onto a 3D web globe on a mobile device, you typically hit a massive wall: memory limits, terrible framerates, and inevitable browser crashes. But at the R&D department of Northern System Service —where we regularly build robust GIS systems and visualize spatial data for Japanese government agencies like JAXA and JAMSTEC—we love pushing browser limits. We didn't want a clunky, pre-rendered video. We wanted real-time, interactive 3D rendering on a smartphone. By rethinking our data pipeline and offloading the heavy lifting to the GPU