JUPITER exascale supercomputer at Forschungszentrum Jülich (Credit: Forschungszentrum Jülich / Sascha Kreklau)
SUBTOPIC

Numerical Weather Prediction (NWP)

Solving the equations of atmospheric motion at exascale, one grid point at a time.

Image: Forschungszentrum Jülich / Sascha Kreklau

From Physics Equations to Operational Forecasts

NWP solves the primitive equations of fluid dynamics and thermodynamics that govern the atmosphere, discretized across a global or regional grid. At kilometer-scale resolution, this produces billions of grid points that must be updated every few simulated minutes, all while a strict operational deadline looms: a forecast that finishes late is worthless. Malgukke's HPC architectures are built around this single constraint — sustained throughput within a fixed wall-clock budget.

HPC Solution Architecture: Observation to Forecast

A typical exascale NWP pipeline, as deployed by centers such as ECMWF on the JUPITER supercomputer:

Observations Satellites, radar, radiosondes, buoys Data Assimilation 4D-Var / EnKF Exascale HPC Core CPU Nodes Fluid dynamics solver GPU Nodes AI/ML forecast (AIFS) Post-Processing Ensemble & bias correction Forecast Delivered within operational window Forecast verification feeds back into the next assimilation cycle

Running on the TOP500: JUPITER

TOP500 — JUNE 2026 LIST

JUPITER — Forschungszentrum Jülich, Germany

JUPITER is Europe's first exascale supercomputer, ranked No. 5 on the June 2026 TOP500 list with 1.000 Exaflop/s sustained HPL performance. Built on Eviden's BullSequana XH3000 platform with NVIDIA GH200 Grace Hopper Superchips, JUPITER is hosted close to ECMWF's Bonn offices and used directly for numerical weather prediction: ECMWF has run its Integrated Forecasting System (IFS) and Artificial Intelligence Forecasting System (AIFS) on the machine as part of the "JEuExa" project, targeting global kilometer-scale forecasting.

Yes — this is a real, currently operating TOP500-ranked system, actively used for the workloads described on this page.

#5
Global TOP500 Rank
1.000
Exaflop/s (HPL)

Voices from the Field

ECMWF researchers directly involved in bringing NWP workloads onto JUPITER:

Nils Wedi

Digital Technology Lead for Destination Earth, ECMWF

On running the first numerical weather prediction simulations with both IFS and AIFS on JUPITER.

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Peter Düben

Head of Earth System Modelling, ECMWF

On why machines like JUPITER are essential to develop large machine learning models such as AIFS at scale.

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