ArWen 2.9.10

ArWen 2.9.10. The desktop stays ArWen Desktop 1.0.10, from the 2.9.0 release.

• Install or upgrade: pip install --upgrade "gpuwm[all-cu12]==2.9.10".
• Integration kit, verification records, and checksums.
• Node GPU gate: Stage 1 and both GPU-shard results, with the tested source revision and card identity.

Changed

• GraphCast (operational and small) runs at every default door: its weights are CC BY 4.0, which permits commercial use, since 2026-08-06.
• Starts from ECMWF open data, AIFS and ECMWF ENS have sea ice, taken from the same cycle's GFS analysis by downloading that one record (about 0.1 MB) by its index.
• IFS open-data starts (0.1 and 0.25 degree) and ECMWF ENS member starts download only the records they read, about a third of the bytes, and AIFS starts about half; the prepared start is unchanged.
• HRRR starts download only the records the preparation reads, about 40 % of the bytes (4.6 GB -> 1.8 GB for a 3 h window); the prepared start is unchanged.
• HRRR native-level starts (--source hrrr-native) download only the records they read: about half the bytes, the soil donor 29 MB instead of 515 MB, and a two-lead start's download in about half the time; the prepared start is unchanged.
• HRRR pressure-level starts (--source hrrr-prs) download only the records they read, about 40 percent of the bytes, and record-subset downloads move their byte ranges over persistent connections; a two-hour HRRR pressure-level start fetched in 16 s instead of 44 s.
• RRFS and RRFS ensemble starts download only the records the start reads, selected from the index beside each file: about 330 MB per lead instead of 870-920 MB, and an ensemble member about 440 MB instead of 1.1 GB; the prepared start is unchanged.
• ERA5 starts from Google's ARCO store download only the compressed blocks that hold the area's rows instead of whole-globe chunks: a 12 x 15 degree area moves 174 MB instead of 836 MB; the prepared start is unchanged.
• GEFS member starts download only the records the start reads, selected from the index beside each file: about 33 MB per member and lead instead of 105-118 MB; the prepared start is unchanged.
• GFS and GDAS starts that read the AWS archive's objects (hosted runs, and cycles older than the grib-filter host keeps) download only the records the start reads: a 3-lead GFS start moves 278 MB instead of 1,556 MB and a GDAS start 553 MB instead of 1,445 MB, and prepares the same bytes.
• Thompson microphysics (mp_physics 8 and 28) fills negative water vapour the way WRF's driver does.
• RUC suites authored from any source start the ground vapour from the air (ruc_qvg_cold_start = "air").
• History frames are written as lossless compressed NetCDF-4: every value reads back unchanged and a frame takes about a third of the disk. --history-compression none writes classic frames.
• Nest preparation on CUDA always uses a certified card and matches CPU preparation byte for byte, so two runs of one case prepare the same child inputs.
• met_intermediate writes WPS intermediates from GRIB2 byte for byte as native ungrib does; initial conditions built from GRIB2 change in the last bits.
• Annual NLCD Developed, Open Space (class 21) maps to grassland instead of urban, so airports, suburbs and small towns no longer stay warm all night with landcover_source = annual-nlcd.
• Choosing a different boundary or surface layer on the HRRR mp28 set runs WRF 4.6.1's Thompson; thompson_version = "wrf_39_noaa" keeps HRRR's.
• Generated MPAS meshes number their cells in Morton order, so neighbouring cells sit together in memory and the dycore step on hex's default 96 -> 3 km zoom globe takes about a third less time.
• rw_rrfs_upp writes RRFS v2 GRIB2 under the message identities NOAA's UPP writes, and composite, 1 km and -10 C reflectivity with no echo are -20 dBZ, as UPP writes them.

New

• Optional Icechunk output stores native forecast history as lossless Zarr v3 snapshots, locally or on S3 (--output-format netcdf,icechunk).
• ghg_input = 1 reads WRF's CAMtr time-varying greenhouse gases in RRTMG and RRTM longwave, and a WRF namelist from a named V4 release (--wrf-version 4.6.1) runs that release's scheme versions.
• rw_mpas_mpassit (MPAS history onto RRFS v2's 3 km Lambert grid) and rw_rrfs_upp (RRFS v2 GRIB2 products) build from source.
• gpuwm domain and gpuwm downscale take --les-closure smagorinsky|tke for grids at LES spacing, and gpuwm domain seeds inflow turbulence on the first LES nest under a 1-D boundary-layer parent (--les-inflow-seeding off skips it).
• [static.highres] lcz_pervious = "split" makes only the paved share of each CGLC-MODIS-LCZ built pixel urban and the rest natural vegetation, for runs without an urban canopy model; the default is unchanged.

Fixed

• Nest-down children at or below 250 m run LES (no boundary-layer scheme, a 3-D closure) instead of 1-D MYNN, which could go non-finite at that spacing; --les-below-m 0 keeps the 1-D scheme.
• Nest-down children at 600 m and finer build their land cover and soil at source resolution, so their 2 m temperature no longer shows 1 km squares.
• Starts from ECMWF open data no longer fail when ECMWF's AWS mirror throttles (503 SlowDown): the fetch waits it out or moves to the next mirror.
• HRRR and RAP soil moisture reaches Noah unchanged again, so Noah runs on HRRR no longer start with dried soil; the Noah mosaic (sf_surface_mosaic = 1) runs on the HRRR route again.
• The revised MM5 surface layer (sf_sfclay_physics = 1) matches an optimised WRF 4.6.1 build word for word in strict mode, and a WRF-file run integrates on the files' own vertical constants.
• Simulated radar skips quick-look frames, so a run with 5-minute quick looks no longer fails.
• Simulated radar velocity on quick-look frames no longer draws a line along a nest's edges.
• A finished forecast no longer hangs at exit holding its card.
• Kernel compile workers end with the run that started them, however it ends, instead of staying behind holding memory.
• IFS 0.1-degree open data starts at its first cycle that carries soil (2026-10-20 12Z); the cycle before it is refused before downloading.
• Hex starts from HRRR get 10 m wind and 2 m humidity on regional boxes west of Greenwich.
• Hex starts from HRRR with no whole HRRR file on disk download the records they decode instead of failing at the intermediate stage.
• rw_mpas_init --first-guess-hydrometeors yes starts an MPAS initial state from the first guess's own cloud, rain, ice, snow and graupel, so hex starts from HRRR no longer begin with no condensate.
• Sea-level pressure maps are smoothed over high terrain, and rw_mpas_stream writes an MPAS history frame about 4x faster.
• MPAS history and diagnostics written by rw_mpas_stream open in netCDF-C and netCDF4-python when they hold a scalar variable.
• A finished ensemble member no longer fails when the product drain is busy; the seal waits for it.
• HRRR starts refused for one out-of-range soil cell outside the domain, or for a one-quantum rounding step, now run.
• A radiation, cumulus or boundary-layer interval that is not a whole number of steps runs every NINT(minutes x 60 / dt) steps, as wrf.exe does, instead of being refused.
• Strict two-domain runs no longer crash at the first nest step.
• Runs with sf_urban_physics = 1 or 20-category land use no longer fail after the forecast when the companion WRF files are written.
• Direct WRF exports carry the 20 terrain-drag statistics for gwd_opt = 3 and the prepared lake depth for use_lakedepth.
• The native wrfinput door keeps an authored mix_full_fields = .false..
• An empty CUDA_VISIBLE_DEVICES stays empty when a forecast is relaunched.
• A plain gpuwm go writes the column store for every output frame; the column store and soundings read compressed frames on every core.
• Disk admission prices quick-look frames at their subset and compressed history at its measured size, so runs are no longer refused for disk they do not need; quick-look frames carry T and PHB only when named.
• rw_soundings draws small batches on the CPU instead of creating a GPU device per batch.
• Soundings with no effective inflow layer show MOSHE as -- instead of a meaningless value.
• RRFS-MPAS initial conditions match the native fork at limited-area boundary edges and run on every core (a 3 km CONUS init: 492 s to 85 s); a GFS cold start no longer rains out over the whole domain in its first hour.
• MPAS maps reduce sea-level pressure from the real terrain, mask a limited-area mesh's boundary rings, include parameterised convective rain in composite reflectivity, and name a graded mesh by its refined and background spacing.
• Soundings colour the MCS Index the right way round: a low value means a likely MCS, so quiet soundings no longer show it in the alarm colour.
• 2 m dewpoint maps of hex limited-area runs leave the area outside the mesh blank instead of painting it -40 F.
• Maps of a run started off the whole hour keep exact valid times and name the init minutes.
• A nested run on a source that posts lead by lead (HRRR, RAP) starts on its first leads instead of waiting for the cycle's last lead.
• A nested run with MYNN TKE advection on (bl_mynn_tkeadvect = true) starts instead of stopping at preflight.
• Runs with Kain-Fritsch cumulus and Thompson microphysics no longer show the cumulus scheme's drizzle as 20-30 dBZ strips at domain and nest edges: its rain now carries a rain number.
• A forecast resumed from a checkpoint with nwp_diagnostics switched on or off runs instead of being refused.
• GDAS starts from the NOMADS grib-filter download the cloud, rain, ice, snow and graupel records the preparation reads, so they prepare instead of being refused.
• Sources that carry cloud, rain, ice, snow and graupel (HRRR and others) no longer feed convective cells into the outer grid through its edges, which showed as straight rain bands running in from the edge.
• A two-domain run from WRF input files starts its nest the way wrf.exe does (blended terrain, temperature and moisture moved to the blended mass, the surface-pressure adjustment) and, with two-way feedback, gives the parent the nest's terrain, land and surface fields.
• A CPU HRRR preparation on a busy host no longer stops at f00 with "f00 mapping used 20 native workers; expected 24".
• The NCEP BUFR reader decodes satellite messages in the WMO subset layout and compressed satellite messages, so the GDAS satellite-wind families decode instead of being refused.
• Snow, graupel and hail since-start maps are headlined "Snow since start, liquid equivalent" and so on, instead of the raw variable name.