| General AWWS | A series of defined parameter thresholds which may affect general offshore operations. |
|---|---|
| HeliOps AWWS | A series of defined parameter thresholds which may affect helicopter flight operations. |
| Crane AWWS | A series of defined parameter thresholds which may affect operation of cranes on offshore installations. |
| Site Specific | Parameters thresholds defined for individual sites. If site not defined behaves as General AWWS. |
| Parameter | Scheme | Warnings | ||
| QNH Air Pressure (hPa) | All | < 910 or > 1100 | N/A | N/A |
|---|---|---|---|---|
| QFE Air Pressure (hPa) | All | < 910 or > 1100 | N/A | N/A |
| Dry Air Temperature (°C) | All | < 0 | N/A | N/A |
| Wet Air Temperature (°C) | All | < 0 | N/A | N/A |
| Wind Chill (°C) | All | < -3 | < -1 | N/A |
| Relative Humidity (%) | All | > 95 | > 90 | N/A |
| Visibility (m) | All | < 250 | N/A | N/A |
| Cloud Base (ft) | All | < 300 | < 600 | N/A |
| Wind Speed (kts) | General | > 40 | > 30 | N/A |
| Crane | > 40 | > 30 | > 20 | |
| Heliops | > 60 | > 45 | > 40 | |
| Wind Gust (kts) | General | > 50 | > 40 | N/A |
| Crane | > 40 | > 40 | > 30 | |
| Heliops | > 70 | > 60 | > 50 | |
| Significant Wave Height (m) | General | > 7 | > 5.5 | N/A |
| Crane | > 4 | > 3 | N/A | |
| Heliops | > 7 | > 5.5 | N/A | |
| Maximum Wave Height (m) | General | > 12 | >9 | N/A |
| Crane | > 7 | > 5 | N/A | |
| Heliops | > 12 | > 9 | N/A | |
| Wave Crest Height (m) | General | > 7 | > 5.5 | N/A |
| Crane | > 4 | > 3 | N/A | |
| Heliops | > 7 | > 5.5 | N/A | |
| TZ Wave Period (s) | General | > 15 | > 10 | N/A |
| Crane | > 15 | > 10 | N/A | |
| Heliops | > 15 | > 10 | N/A | |
| TP Wave Period (s) | General | > 20 | > 15 | N/A |
| Crane | > 20 | > 15 | N/A | |
| Heliops | > 20 | > 15 | N/A | |
| Parameter | Description |
| Wind Dir (°) | 10 minute mean wind direction. |
|---|---|
| Wind Speed (kts) | 10 minute mean wind speed. |
| Wind Gust (kts) | 10 minute maximum of 3 second mean wind speed. |
| Hs (m) | Significant wave height (mean of highest 33% of waves). |
| Hmax (m) | Largest single wave. |
| Tz (s) | Mean zero crossing period. |
| Air Temp (°C) | 10 minute mean dry air temperature. |
| Dew Point (°C) | 10 minute mean dew point. |
| Cloud Level 1 (ft) | Height of 1st cloud base. |
| Cloud Level 2 (ft) | Height of 2nd cloud base. |
| Visibility (m) | 10 minute mean horizontal visibility. |
| QNH (hPa) | 10 minute mean calculated sea level air pressure. |