Migrate from data.dynamical.org

data.dynamical.org is going away — plan on August 31, 2026. In practice we will turn URLs off dataset by dataset over the following months rather than all at once, so nothing breaks the morning of September 1.
The replacement datasets are stored as Icechunk Zarr repositories. Both access patterns below read the Icechunk 2.0 version of a dataset, which makes Icechunk 2 a required dependency.
Only how they are opened needs to change. The Icechunk versions are identical in structure, naming, attributes, chunking/sharding, and content — drop-in replacements for the deprecated Zarrs.

Replace each hard-coded https://data.dynamical.org/.../latest.zarr URL with one of the two supported ways to open a dataset. Both need Python 3.12 or newer, and both resolve the current repository from our STAC catalog, so your code does not need to track storage locations or version changes.

dynamical-catalog

A thin STAC and Icechunk wrapper that ensures minimum dependency versions. Install dynamical-catalog>=0.7.0 and pass the dataset ID from its catalog page.

import dynamical_catalog

ds = dynamical_catalog.open("noaa-gfs-forecast", chunks=None)

STAC and Icechunk

Resolve the icechunk-https asset from the dataset's STAC Collection each time your application opens a repository. Do not copy and permanently hard-code the asset URL. Any HTTP client can read the Collection — the example below uses httpx, and pystac works too, but neither is required.

import httpx
import icechunk
import xarray as xr

url = "https://stac.dynamical.org/noaa-gfs-forecast/collection.json"
href = httpx.get(url).json()["assets"]["icechunk-https"]["href"]

repo = icechunk.Repository.open(icechunk.http_storage(href))
session = repo.readonly_session("main")
ds = xr.open_zarr(session.store, chunks=None)

Python is not a requirement either. Icechunk publishes a JavaScript/TypeScript client (@earthmover/icechunk, paired with zarrita) and a Rust crate (icechunk), both of which open the same icechunk-https asset over plain HTTP.

Have an agent do it

Paste this into a coding agent running in your repository.

Replace every data.dynamical.org URL in this repository with dynamical.org's
supported access, and leave no hard-coded storage locations behind.

Context to read first:
- https://dynamical.org/llms.txt for current access patterns and dataset IDs.
- https://stac.dynamical.org/catalog.json is the source of truth. Confirm each
  dataset ID against it rather than guessing.

Rules:
- A legacy URL maps to a dataset ID by dropping the host and joining the path
  with hyphens: data.dynamical.org/noaa/gfs/forecast/latest.zarr ->
  noaa-gfs-forecast. Exception: /noaa/gfs/analysis-hourly/ is retired, use
  noaa-gfs-analysis.
- Prefer dynamical_catalog.open("<dataset-id>"). It needs Python 3.12+ and
  dynamical-catalog>=0.7.0.
- If a new dependency is not an option, resolve the "icechunk-https" asset from
  the dataset's STAC Collection at open time. Any HTTP client can read the
  Collection; pystac is not required. Do not hard-code the asset href, the S3
  bucket, or a version number.
- Drop any ?email= query argument. It is no longer used.
- Opened datasets are Icechunk 2 repositories, so Icechunk 2 is a required
  dependency. They are identical to the legacy archive in structure, naming,
  attributes, chunking/sharding, and content — only the open call changes, so
  leave the surrounding analysis code alone.

Report every URL you could not map, and every place a dataset ID had to be
chosen rather than derived.

What changes

Opening requires Icechunk 2 and Python 3.12 or newer.
The public STAC Collection is the source of truth for the current repository.
Dataset IDs replace data.dynamical.org paths.
The optional ?email= query argument is no longer used.
Nothing about the data itself. Variables, attributes, chunking, and values are unchanged.

Help

If the replacement does not cover your access pattern, email [email protected] with the data.dynamical.org URL, variables, spatial subset, and time range you use.