SIGWX hazard symbols
Hazard symbols:
| Symbol | Shows | Also carries |
|---|---|---|
| Scalloped line | Encloses area the written conditions apply to | n/a |
| Sandstorm/dust storm | Widespread sandstorms or dust storms | Scalloped line, height symbol, sandstorm symbol |
| -V- | Severe squall line | Oriented to true north, representative length |
| Tropical cyclone symbol | Tropical cyclones | CB-coverage and height criteria added when met; chart note: latest TC advisory, not prognostic position, is for public dissemination |
| Volcanic eruption symbol | Volcano location | Side box: volcano name and international number, lat/long, date/time of first eruption |
| Radioactive material symbol (black on yellow circular background) | Release site | Side box: lat/long, date/time of release, check NOTAM for area |
| Heavy dashed lines + height symbol | Moderate or severe turbulence, in cloud or clear air; includes wind shear and mountain-wave turbulence | Convective turbulence not included |
Jet stream (core 80 kt or stronger): true-north arrow, pennants/feathers for speed.
| Marking | Meaning | Condition |
|---|---|---|
| Double-hatch across core | Speed change of 20 kt or more | Jet 100 kt or more |
| Vertical-depth pair (base/top of 80-kt isotach) | Jet depth | Jet 120 kt or more only |
Tropopause height:
- Flight level in a small box; centre = forecast grid point.
Trap: briefing a TC from the chart's prognostic position instead of the latest advisory; reading convective turbulence from the dashed lines instead of the CB symbol.
References
- TC AIM MET 12.2