The role of spack-stack in the operational implementation of the NAVY's next-generation weather forecasting model
In 2025, the United States Naval Research Lab (NRL) is transitioning its next-generation numerical weather prediction (NWP) system NEPTUNE (Navy Environmental Prediction sysTem Using a Nonhydrostatic Engine) to their operational partner, Fleet Numerical Meteorology and Oceanography Center (FNMOC). The transitioning of innovations from research to operations (R2O) and the feedback from operations to research (O2R) is one of the major challenges in the NWP world, to the extent that it is sometimes referred to as the "valley of death". One of the contributors to this challenge is that the environment in which the NWP systems operate can differ greatly. The development and testing often take place on different high-performance computing (HPC) systems, with varying environments of software (also referred to as software stacks), and with different workflows than in operations.

For the first operational implementation of NEPTUNE in 2025, NRL and FNMOC are adopting a novel approach to address some of these challenges: First, FNMOC produces forecasts on highly secured, fenced-off partitions on the same HPC systems that NRL uses for its development. Second, NRL provides software environments based on spack-stack. The spack-stack project is a joint effort of several major federal agencies and UCAR labs. It leverages the spack package manager developed by Lawrence Livermore National Laboratory and supported by a large community. Spack-stack utilizes modern software development practices like continuous integration (CI) and a fast release cycle. Utilizing these features, NRL implemented robust continuous integration and continuous deployment (CI/CD) of spack-stack environments on the HPCMP systems to populate spack source mirrors and binary caches. This allows FNMOC to deploy bit-for-bit identical software environments in their secured environments in a matter of minutes.

In this presentation, we will revisit the challenges in the R2O2R cycle in NWP, provide an overview of the joint spack-stack effort, and cover its role in the deployment of NEPTUNE in operations. We will further discuss opportunities for collaboration between the NRL developers and the HPCMP system administrators to streamline the deployment of spack-stack environments, and to simplify the provisioning of software environments for HPCMP users in general.
IMPACT
Accomplishment: Introduced spack-stack software environments at NRL for NEPTUNE research, development and operational implementation; Result: More efficient research to operations to research (R2O2R) processes lead to better forecast sooner
PRESENTER
Heinzeller, Dom
dom.heinzeller@ucar.edu
720-595-5404
NRL @ UCAR/CPAESS
CO-AUTHOR(S)
Reinecke, Alex
patrick.a.reinecke.civ@us.navy.mil
CATEGORY
Weather &  Ocean Modeling & Sim
SECONDARY CATEGORY
Other
SYSTEM(S) USED
Navy DSRC Blueback, Narwhal, Nautilus; testing on ERDC DSRC Wheat and ARL DSRC Jean