GribStream Blog
CDAS1 climate assimilation fields now available
GribStream now supports NOAA CDAS1 (Climate Data Assimilation System): global climate-oriented assimilation fields on a 1.0 deg grid with 0-9 hour lead times.
On February 8, 2026, we added NOAA CDAS1 (Climate Data Assimilation System) to GribStream.
CDAS is a useful complement to short-range operational systems: it gives you a consistent global assimilation baseline that is often better suited for climate diagnostics and retrospective analysis workflows.
What CDAS1 is
CDAS1 is a global data-assimilation stream designed for climate-oriented analysis. Like other assimilation systems, it combines model background fields with observations to produce gridded atmospheric states, but it is commonly used where consistency and broad-scale context matter more than fine spatial detail.
CDAS is published in NOAA's CFS archive ecosystem, so it fits naturally with seasonal and extended-range analysis pipelines.
Coverage on GribStream
- GribStream code:
cdas(model page) - Coverage: global
- Resolution: 1.0 deg (~111 km)
- Cycle times: 00/06/12/18 UTC
- Lead times: 0-9 hours
The coarser grid lowers cost for global studies while still providing a broad atmospheric parameter set.
What it is used for
CDAS is a strong fit for workflows such as:
- Climate baselines: build reference climatologies and anomaly workflows.
- Retrospective evaluation: benchmark model behavior over long periods.
- Feature engineering at scale: produce global predictors without high-resolution compute cost.
- Cross-system comparison: contrast climate-oriented assimilation with operational systems like GFS.
How to use it in practice
Use standard GribStream endpoints:
/api/v2/cdas/runsfor per-cycle snapshots/api/v2/cdas/timeseries(alias:/history) for best-available sequences
A practical pattern is combining CDAS with CFS products: use CDAS for analysis/baseline context and CFS for longer-horizon scenario work.