METAR Remarks (RMK Line)
Canadian METAR RMK line adds observed detail the coded groups do not carry. Reports, where observed:
- Cloud or obscuring phenomena layer type, in eighths of sky covered (oktas); type codes:
metar-cloud-abbreviations. - General weather remarks.
- Sea level pressure.
| Remark | Meaning | Rule / example |
|---|---|---|
| CB/TCU | Convective cloud (cumulonimbus or towering cumulus) | Any amount always reported, even embedded in another layer or distant from station |
| FROIN | Frost on indicator | Used when frost observed since previous report |
| SLP | Sea level pressure, hPa | Last mandatory field in METAR. SLP134 = 1013.4 hPa |
| Density altitude | Density altitude | Added after SLP when 200 ft or more above aerodrome elevation. DENSITY ALTITUDE 2500FT |
| PRESFR | Pressure falling rapidly | Get latest altimeter setting |
| PRESRR | Pressure rising rapidly | Get latest altimeter setting |
| RMK | Remark(s) | Prefaces the whole line |
| CIG | Ceiling | Forecast contraction; appears inside remarks |
| OBSC | Obscure, obscured, obscuring | Forecast contraction; appears inside remarks |
Direction convention: remark directions run clockwise. PRFG SE-N = fog partially covers aerodrome from southeast to north.
Trap: reading remark directions as counter-clockwise. They run clockwise.
References
- TC AIM MET 8.1
- TC AIM MET Table 15.1 (Aviation Forecast Abbreviations, pp.179-182)