Stages 4-5 of the HRDPS plan. Lands the Rust forecast-hour pipeline
for source='hrdps' grid_tasks rows.
What ships:
- `hrdps_fetcher.rs` — sibling of fetcher.rs for ECCC's MSC Datamart
shape: date-prefixed URLs, one variable per GRIB2 file, concurrent
fetch + byte-concat into a single multi-record blob. wgrib2 reads
multi-record files natively so the downstream decoder path is
unchanged. Mirrors lib/microwaveprop/weather/hrdps_client.ex.
- `grid::hrdps_only_points()` + `grid::hrdps_grid_spec()` — Canadian
cells (49-60°N, -141 to -52°W) minus the HRRR overlap. Disjoint
from conus_points by construction.
- `db::TaskSource` enum + `source` column on ClaimedTask. claim_next
surfaces source for forecast lane dispatch; claim_next_analysis
filters to source='hrrr' only (HRDPS analysis path is not yet
ported — would need native-duct + NEXRAD + commercial merges that
Rust doesn't have for HRDPS).
- `pipeline::run_chain_step_hrdps` — fetch combined blob, decode with
HRDPS grid spec, drop HRRR-overlap cells via a HashSet of
hrdps_only_points, back-fill DPT from DEPR (HRDPS publishes DEPR
as primary), score every band, write `<band>/<iso>.hrdps.prop`.
Skips per-valid_time profile + scalar artifacts since those would
clobber HRRR's at the same valid_time — surfacing HRDPS on /weather
is a separate stage.
- worker.rs dispatches forecast lane on (kind, source) — Hrrr →
run_chain_step, Hrdps → run_chain_step_hrdps. Analysis stays
HRRR-only. Worker constructs an HrdpsClient alongside HrrrClient.
- `scores_file::write_atomic_hrdps` writes to `.hrdps.prop` with the
Canadian grid spec via the new encode_with_spec. Coexists with the
HRRR `.prop` file for the same (band, valid_time).
163 unit tests pass; backfill_dpt_from_depr handles surface and
pressure-level levels with no double-fill when DPT exists.
Graham McIntire
46c2d84e5c