Two follow-ups to the earlier /skewt work:
1. Interactive crosshair (matches the SPC-viewer feel from the
reference screenshot). Mousing over the diagram now drops a
horizontal pressure cursor with a top-left readout box showing the
pressure at the cursor's altitude (mb), the height in m and ft,
and the linearly interpolated temperature and dewpoint at that
level. Two coloured dots track the T and Td traces along the
cursor so the user can read the spread visually.
Mechanics: SkewtSvg.geometry/0 exposes the plot geometry (left,
right, top, bottom, p_bottom, p_top, t_min, t_max, skew) as JSON;
SkewtSvg emits an initially-hidden <g class="skewt-cursor"> layer.
A new Skewt hook in assets/js/app.ts inverts pressure_y to recover
pressure from the cursor's viewBox-Y, walks the (descending-pres-
sorted) profile to interp T/Td/height, and updates the elements.
The hook also handles mouseleave to hide the cursor and uses the
SVG's screen-CTM so the math stays correct under any container
aspect-ratio resize.
2. DB fallback for `available_valid_times`/`load_profile`. When the
on-disk `ProfilesFile` has nothing for the location-and-window
(true on dev, transient on prod between chain runs), SkewtLive
now falls back to `HrrrProfileLookup.{list_valid_times_near,
read_point_near}/3` against the `hrrr_profiles` Postgres table.
The lookup uses the same ±0.07° spatial tolerance and the
`(lat, lon, valid_time)` unique index that `Weather.find_nearest_
hrrr/3` already relies on, so the queries are index-only.
Returned shape matches `ProfilesFile.read_point/3` so SkewtLive
reads from either source transparently. NaiveDateTime → UTC
normalisation is centralised in `ensure_utc/1` so the LiveView
sees `%DateTime{time_zone: "Etc/UTC"}` regardless of which side
produced the value.
Tests: 6/6 new HrrrProfileLookupTest cases (list/limit/tolerance,
read nearest cell, nil for far cells, picks closest among matches),
3/3 SkewtLiveTest still green, 2,894 total Elixir tests + 221
properties green via mix test (one pre-existing flaky test in
admin/contact_edit_live re-runs clean). mix credo --strict clean.
mix assets.build clean.
The /skewt page was empty in prod because Phase 2 of the Rust cutover
moved f01..f18 grid scoring to Rust but left profile-file writing only
on the analysis (f00) path. Result: /data/scores/profiles/ accumulated
one file per chain run instead of nineteen, so SkewtLive only ever saw
the analysis hour — and that hour falls outside the 1 h past cutoff
within an hour of the chain finishing, leaving the page empty most of
the time.
Two surgical fixes:
* `pipeline::run_chain_step` now builds `profile_entries` alongside
`prepared` from the merged grid in a single iter pass, then spawns
`profiles_file::write_atomic` on the blocking pool to overlap the
NFS write with the score-band scoring/write fan-out — same pattern
`run_analysis_step` already uses. `ChainStepStats` gains
`profile_cells_written` so the worker log line is symmetric with
the analysis step's existing field and a future failure mode that
drops the profile would show up as a divergence.
* `SkewtLive.available_valid_times/0` widens the past cutoff from
1 h to 3 h. The chain's analysis hour can be ~70 min old by the
time the next chain finishes (and ~2 h on a missed cycle), so the
1 h cutoff was leaving the page blank during normal transients.
18 h forward window unchanged.
Cosmetic: cargo fmt picked up trivial rewrites in decoder/fetcher/
native_duct/hrrr_point_worker that had drifted; rolled in.
Verification: cargo build --release, cargo clippy --lib --bins -D
warnings, cargo test --lib (134/134), mix test
test/microwaveprop_web/live/skewt_live_test.exs (3/3) all green.
Single search bar accepts an address, Maidenhead grid square, or
callsign; resolves it to lat/lon via Geocoder / Maidenhead /
CallsignLocation (cheapest classification first), snaps to the HRRR
grid via the existing ProfilesFile reader, and renders an SVG
Skew-T-Log-P with isobars, skewed isotherms, dry/moist adiabats, and
mixing-ratio lines. A button row picks between every available
forecast hour (now → f18); default is the most recent analysis.
Right pane lists derived stability and refractivity stats from
SoundingParams.derive (PWAT, BL depth, K-index, lifted index, min
dN/dh, ducting status + per-duct base/top/ΔM).
Renderer is server-side SVG so the page works without JS and serializes
into the LiveView payload as a single tag. Wind barbs are deliberately
omitted — HRRR's persisted profile carries wind only at 10 m AGL.
