Three additions that bring the diagram closer to the SPC sounding
viewer's full-information chart:
* Wet-bulb temperature trace, plotted as a thinner blue line under
the dewpoint trace. Comes from a Stipanuk-style bracket between
the level's dewpoint and dry-bulb temperatures (already used by
`SkewtParams` for the wet-bulb-zero level — now public so the
renderer can call it per level).
* Environment virtual-temperature trace and parcel virtual-T
trajectory, both as thin pinkish dashed lines. The parcel
virtual-T is the actual buoyancy curve CAPE integrates against,
so showing it next to the dry-bulb parcel ascent makes the
moisture correction visible. New `SkewtParams.virtual_temp_c/2`
and `/3` helpers, plus `SkewtParams.mixing_ratio/2`.
* Critical-level rail on the right edge. Each of LCL / LFC / EL /
0 °C / WBZ that resolves on the current profile gets a short
horizontal tick at the right of the plot and a `<label> <p> mb`
tag just outside it — matches the SPC chart's `143 mb (mix)` /
`158 mb (mix)` annotation column. SkewtLive computes the
pressures (and converts the height-keyed 0 °C and WBZ from
SkewtParams back to pressure via `pressure_at_height/2`) before
handing them to `SkewtSvg.render/2`.
Wind-derived overlays (hodograph, wind barbs) remain off — HRRR
profile data is wind-free above 10 m AGL.
mix test: 27 / 27 across the four /skewt-related test files,
2,902 / 2,902 + 221 properties on the full suite. mix credo --strict
clean (one cyclomatic-complexity refactor extracted along the way).
Two changes that bring /skewt visually and analytically into parity
with the NOAA SPC sounding viewer
(https://www.spc.noaa.gov/exper/soundings/):
NOAA-style line set
-------------------
Updated the SkewtSvg style block to match the public SPC chart:
* Temperature trace ........ pure red (#ff0000) at 2.5 px stroke
* Dewpoint trace ........... pure green (#00aa00) at 2.5 px stroke
* Isotherms ................ dashed teal (#14b8a6)
* Dry adiabats ............. solid orange (#f59e0b)
* Moist (saturated) adiabats dashed sky-blue (#38bdf8)
* Mixing-ratio lines ....... dotted darker green (#16a34a), with
labels at 700 mb showing the g/kg
value, drawn only below 600 mb (matches
the SPC chart's lower-band number row)
* Parcel ascent ............ new dashed grey (#475569) line, drawn
whenever SkewtParams.derive returns a
non-empty parcel_trace
The mixing-ratio set is the SPC standard (0.4 / 0.7 / 1 / 2 / 3 / 5 /
8 / 12 / 16 / 20 g/kg) instead of the prior arbitrary set.
SkewtParams: SPC parcel-theory + indices module
-----------------------------------------------
New `Microwaveprop.Weather.SkewtParams` derives the parameter set that
ships in the SPC `*.txt` companion file:
* LCL pressure / temperature / height (Bolton 1980 eq 22)
* LFC pressure / height
* EL pressure / height
* SBCAPE, SBCIN (J/kg, virtual-temperature integration with
surface parcel)
* 3 km CAPE
* Lifted Index (parcel ↔ environment T at 500 mb)
* Freezing level (T = 0 °C height) and Wet-Bulb Zero
* DCAPE (downdraft CAPE — picks the min-θₑ source level in
400–700 mb, descends moist-adiabatically to surface)
* Layer lapse rates: sfc–3 km, 700–500 mb, 850–500 mb
* `parcel_trace` — pressure/temperature trajectory used by
SkewtSvg to draw the dashed parcel-ascent overlay
Wind-derived indices (SRH, BWD, Bunkers motion, SCP, STP, SHIP) are
deliberately *not* produced and the LiveView surfaces a one-line note
explaining why: HRRR persists wind only at 10 m AGL, so per-pressure-
level shear can't be computed from this data source.
LiveView panel restructured into grouped sections (Surface, Convective
parcel, Levels, Lapse rates, Moisture/stability, Refractivity) so the
layout matches the SPC viewer's order. The Levels rows show pressure
*and* height ("872 mb · 1,140 m") for quick cross-reference between
the diagram axis and the readout.
Tests: 8/8 new SkewtParamsTest cases (LCL Bolton check, saturated-air
edge case, full field-set presence, summer profile produces SBCAPE > 0
and LI < 0, capped profile produces SBCAPE = 0 and LI > 0, freezing
level interpolated correctly, sfc–3 km lapse rate, empty profile no
crash). 25/25 across all skewt-related test files. mix test green
(2,902 / 2,902 + 221 properties), mix credo --strict clean, mix
assets.build clean.
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.
