ArWen 2.8.4

ArWen 2.8.4 adds simulated radar to forecasts, ports WRF's older implicit vertical-advection variant, makes legacy RRTMG shortwave follow WRF on low-top domains, and separates WRF comparison from observation validation throughout the documentation.

• Install or upgrade: pip install --upgrade "gpuwm[all-cu12]==2.8.4".
• Integration kit, verification records, and checksums.
• Node GPU gate: Stage 1 and both GPU-shard results, with the tested source revision and card identity.

New

• [simulated_radar] writes native radar volumes and PPI loops while a forecast runs. Sites, scan ladders, timing, fields and formats are configurable. Level II and CfRadial 1 are the defaults; CfRadial 2 and ODIM are optional. Before fetching, a forecast checks the radar writer and the scan's memory and adds listed sites' radar output to its disk check; ensemble and local-cycling members refuse the table by name. gpuwm simulated-radar replays saved full-column histories into radar afterwards, and the manifest records every artifact's path, hash, scan time and source revision. Off by default.
• gpuwm simulated-radar --describe reports the installed radar support, and --estimate reports scan samples, memory and an output-size bound before any history is read.
• zadvect_implicit_variant = "wrf_legacy" selects WRF's older implicit vertical-advection split and scalar mass weighting, on resident grids and on [devices] tiles. The default stays "wrf_471"; the older variant changes forecast answers.

Fixed

• Legacy RRTMG shortwave follows WRF on columns with no layer above the troposphere switch (a model top below about 190 hPa, as on shallow or idealized domains): the solar source of bands 16, 17, 27, 28 and 29 is zero there, as WRF leaves it. The batched path read leftover GPU memory for bands 16 and 27, which gave NaN or impossible surface fluxes. Answers change only on such columns.
• The documentation distinguishes code verification, solution verification and validation against observations. WRF comparisons name their reference version, tested build and limits. Physics profiles use comparison names. Old profile IDs and labels are still accepted wherever an ID is entered, and a preparation sealed under an old ID still matches and extends. Suites with no current matched WRF run, the defaults included, report supported-not-wrf-verified, and a prepared forecast prints one line saying so; the run continues.

Local data assimilation stays experimental and its ordinary desktop entry point stays hidden. Advanced users enable it with gpuwm tui --enable-local-da.

Known limits: the web GUI is a preview and the desktop app remains the full way to run ArWen; a single-domain preparation still refuses a [perturbation] block; WRF's gwd_opt = 2 is not ported and is refused.

The verification records identify completed artifact and startup checks, the short GPU forecast, and retained component evidence. They do not establish general forecast skill or whole-model parity.

Installation and usage | Full changelog