2424/461 flashes / minutes

An afternoon and evening of lightning over the Cariboo and Chilcotin, 30 June 2021, heard from a point that follows the storm. 51.19-53.50 N, 124.89-120.59 W, 14:43 to 22:24 PDT (21:43 to 05:24 UTC): at the default pace, about five flashes a second.

🎧 Headphones recommended · left-right and distance cues
Land acknowledgement (draft)

This storm passed over the unceded and ancestral territories of the Secwépemc, Tŝilhqot’in and Dakelh (Carrier) peoples, in the country now called the Cariboo and Chilcotin, and close to the lands of the Northern St’át’imc and Nlaka’pamux. I recognise everyone who has cared for this land, its waters, its ecosystems and its kin since time immemorial, and who care for them now, in a climate that is changing the land, the water, and the storm.

Draft for review: the Nations named have not reviewed or endorsed this wording, and I take all responsibility for errors and omissions.

About this page: sources and limits
  • Flashes. 2,424 optical flashes from the NOAA GOES-17 Geostationary Lightning Mapper, 30 June 2021, 14:43 to 22:24 PDT (21:43 UTC on 30 June to 05:24 UTC on 1 July). Times on this page are Pacific Daylight Time, UTC minus 7 hours, with UTC in brackets; the flash record and the reanalysis are kept in UTC. The flashes kept lie inside 49.0 to 53.5°N and 125 to 118°W. The cluster runs up to the box's northern edge, so flashes farther north are not in this set.
  • Weather. Open-Meteo reanalysis at 35 points (sea-level pressure, wind at 10 and 100 m, temperature) and ERA5 pressure levels at the same points. Temperature is corrected with hourly readings from 81 Environment and Climate Change Canada stations: the correction is each station's difference from the reanalysis, spread to your pin by distance and faded away from stations. Held back one station at a time, the error falls from 4.5 C to 2.0 C. Valley-floor and mountain pins are the weakest; the correction does not know elevation.
  • The pin. By default it chases the storm: the densest cluster of the last 10 minutes, stood off 10 to 20 km on the left of its motion, so strikes arrive as distant flashes with direction. Drag the pin or click the map to take it back.
  • What you hear. Each flash heard within the reach (90 km by default) is a drum hit; the strings, flute, organ, tuba and bear sax follow the weather at the pin (see "How the data becomes sound"). The sound is a composed transform, not a recording of thunder. Real thunder carries tens of kilometres at most.
  • Not claimed. This page is about an afternoon and evening of lightning in a hot, dry summer, not about any one place or fire. It says nothing about what started any fire.
  • Height correction. The pin's ground height comes from a 2 km elevation grid (AWS Terrain Tiles). A lapse rate (the cooling of air with height) can lift or drop the reanalysis temperature from the height of the weather nodes to the ground under the pin: a fixed 6.5 C per km, a guess from humidity (dry air 9.8, saturated 4 to 6), one from the reanalysis profile, or one fitted to the stations hour by hour. Held out one station at a time (81 stations), none improves on the station correction alone: all five land within 0.13 C of each other, and before the station correction the three physical options make the reanalysis worse (raw error 6.0 to 7.7 C against 4.5 C with none). So the default is off and the lapse rate shown is the one you choose. The fitted option follows the stations as they are: in the afternoon the higher stations ran warmer than the reanalysis, the reverse of the textbook lapse rate, and in the evening they ran cooler. Treat it as a curiosity, not a measurement of the atmosphere.
  • Upper air. Wind and temperature at 850 hPa (about 1.5 km) and 700 hPa (about 3 km) come from the ERA5 pressure-level reanalysis (Copernicus). They draw the wind rose and temperature path; they do not yet drive any sound.
  • Credits: flashes NOAA/NESDIS (open data); weather Open-Meteo.com (CC BY 4.0); upper air: generated using Copernicus Climate Change Service information (ERA5, 2021; neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains); stations Environment and Climate Change Canada (Open Government Licence - Canada); instruments VSCO 2 CE and Karoryfer (CC0): the organ, strings, thunder roll and thunder boom are VSCO 2 CE samples trimmed or looped, and the crack is a processed VSCO 2 CE percussion hit; relief AWS Terrain Tiles (sources), tinted with Natural Earth II land cover (public domain); rivers and lakes: BC Freshwater Atlas, contains information licensed under the Open Government Licence - British Columbia; map Leaflet.

Spatial Propagation Field & Terrain Corridors

| 0 strikes in view · Total: 0 / 2,424
Click strike for energy & lag
📍 Drag observer pin or click map to 'travel'. Rings = acoustic arrival (15s, 45s, 90s). Observer: loading
Time: 2021-06-30 14:43:58 PDT (21:43:58 UTC) Air: 40.4°C · 980.2 hPa · Wind: 10 km/h · Shear: 6 km/h
--
Air-- Pressure-- Wind 10 m-- Wind 100 m-- 700 hPa wind-- Ground-- Lapse rate-- Heard--
wind from: 10 m teal · 700 hPa violet
2 m (across) · 850 hPa (up), °C

Sound layers (switch any off)

How the data becomes sound
  • Each flash is a drum hit on a 1/8-second grid. The strongest flash heard in each eighth-second also gets a crack when it is hard enough and within 45 km, softer and duller the farther it is. Distance picks the drum (under 12 km log drum, to 30 km conga or tumba, to 60 km bass drum or timpani, beyond that low timpani), is a lag (about 3.5 ms per km, capped at 0.3 s, plus a small fixed random looseness; real sound takes 2.9 s per km), and dulls the sound. Optical energy sets how hard it is hit. Direction sets left and right. Big hits drag a duller echo behind them, and the biggest ring a gong.
  • Dense moments: three hits at most per step; the rest of a crowded step is heard as a shaker (rain on the drum heads), and five or more flashes in one step bring a quiet low roll (at most every 12 s).
  • Harmony has three versions to compare. B (default) holds the third back and sounds a suspended 2nd, so the harmony neither says major nor minor; temperature still moves the colour note (Lydian when hot, Dorian otherwise). A follows temperature through D Lydian (the hottest third of this storm's pin temperatures), Dorian (the middle) and Aeolian (the coolest third); the page prints the limits when it loads. C alternates F♯ and F, 24 s a turn, stays in Dorian, and lifts the cello an octave.
  • Surface wind picks the cello's note from the mode (stronger wind, higher degree), one change at most every 4 s. Wind at 100 m above 12 km/h breathes a low flute. Wind shear brings the organ.
  • Events are set from this storm's own changes along the chase (the page says the numbers when it loads): the tuba sounds on a sea-level pressure fall in the last 30 min and also swells continuously with the rate of fall; the bear sax sounds on a surface wind change or a gust rise in the last 30 min. At most one of each every 8 s.
  • The drone (contrabass, cello D and A) never changes: it is the ground the changes are heard against.

Space and reach

Audition one flash:
Wind from. Teal: 10 m (petals: how often). Violet: 700 hPa, about 3 km up. The shaded angle is the turn with height.
Temperature path: 2 m (across) against 850 hPa (up). Amber is the path so far; the diagonal is no change with height.

Atmospheric Covariates & Lightning Density (Synoptic & Mesoscale EDA)

Synchronized time series across the 7.68-hour storm outbreak. Click or drag anywhere on the graphs to jump to and hear that specific part of the storm.
How to read the lanes
⚡ Lane 1: Every flash of the storm (dim bars, 15 min, energy dots) and the ones the pin hears (coloured by drum layer: log drum <12 km, conga/tumba <30, bass drum/timpani <60, low timpani farther); the bracket spans the stretch of the storm the pin hears
🌡️ Lane 2: Corrected temperature (mode colour)
📉 Lane 3: Sea-level pressure; red bands = the tuba rule is true
💨 Lane 4: Surface wind (cello), 100 m wind (flute above the dashed line), shear (organ); violet bands = the bear sax rule is true
⛰️ Lane 5: Ground height under the pin (grey) and lapse rate used (amber; dashed = dry 9.8 K/km)
Key Moments:
Storm Elapsed: +00h 00m · 2021-06-30 14:43:58 PDT (21:43:58 UTC) Strikes: 1 / 15m · Temp: 40.4°C (D Lydian) · Pres: 980.2 hPa · Winds: 10 km/h (10m) / 16 km/h (100m)

Local Airmass Telemetry (Interpolated at Observer)

Air temp (2m)
-- °C
Mode
Sea-level pressure
-- hPa
Tuba on a fall
Surface wind (10m)
-- km/h
Cello note
Wind at 100m
-- km/h
Flute above 12 km/h
Wind shear
-- km/h
Organ
Upper air
-- °C
850 hPa; 700 hPa wind
Ground under the pin
-- m
height correction
Lapse rate used
-- K/km
humidity, dry and moist
Last drum heard
-- km
layer, lag

Lightning & Airmass Event Log

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