Adds mix hrdps.probe — throwaway wedge that retires URL/projection/decode
risks against MSC Datamart. Verified against five Canadian cities with
plausible 2m temperatures via wgrib2's native rotated-lat/lon support.
Findings update what we knew:
- ECCC reorganized to date-prefixed paths; the old /model_hrdps/ root
404s now. Real URL is dd.weather.gc.ca/{YYYYMMDD}/WXO-DD/model_hrdps/...
- HRDPS publishes one variable per GRIB2 file (~3.5 MB each), not
HRRR's bundled wrfsfcf format. ~14 files per cycle/forecast hour.
- wgrib2 -lon LON LAT handles the rotated grid natively — no manual
reprojection math needed.
New plan at 2026-04-29-hrdps-canadian-prop-grid.md supersedes the
2026-04-13 one (which assumed HRRR-style idx + byte-range fetches that
don't apply). Probe deletion is a Stage 10 step in the new plan.
Graham McIntire
14e81f9251