Feedback

If you have any comments, please send an e-mail to feedback at muir-matheson dot com.

Help

  1. Warning Scheme
  2. Parameters

Warning Scheme

Many of the realtime display pages within this website utilise a colouring scheme to indicate when certain data parameters exceed various threshold limits which may affect various offshore operations from a safety perspective. Primarily, there are three defined schemes, these being:
General AWWSA series of defined parameter thresholds which may affect general offshore operations.
HeliOps AWWSA series of defined parameter thresholds which may affect helicopter flight operations.
Crane AWWSA series of defined parameter thresholds which may affect operation of cranes on offshore installations.
Site SpecificParameters thresholds defined for individual sites. If site not defined behaves as General AWWS.
The following table lists the AWWS warning level thresholds for each parameter and scheme:
ParameterSchemeWarnings
QNH Air Pressure (hPa)All< 910 or > 1100N/AN/A
QFE Air Pressure (hPa)All< 910 or > 1100N/AN/A
Dry Air Temperature (°C)All< 0N/AN/A
Wet Air Temperature (°C)All< 0N/AN/A
Wind Chill (°C)All< -3< -1N/A
Relative Humidity (%)All> 95> 90N/A
Visibility (m)All< 250N/AN/A
Cloud Base (ft)All< 300< 600N/A
Wind Speed (kts)General> 40> 30N/A
Crane> 40> 30> 20
Heliops> 60> 45> 40
Wind Gust (kts)General> 50> 40N/A
Crane> 40> 40> 30
Heliops> 70> 60> 50
Significant Wave Height (m)General> 7> 5.5N/A
Crane> 4> 3N/A
Heliops> 7> 5.5N/A
Maximum Wave Height (m)General> 12>9N/A
Crane> 7> 5N/A
Heliops> 12> 9N/A
Wave Crest Height (m)General> 7> 5.5N/A
Crane> 4> 3N/A
Heliops> 7> 5.5N/A
TZ Wave Period (s)General> 15> 10N/A
Crane> 15> 10N/A
Heliops> 15> 10N/A
TP Wave Period (s)General> 20> 15N/A
Crane> 20> 15N/A
Heliops> 20> 15N/A

Parameters

The following table describes the parameters displayed on the data map and data table pages:
ParameterDescription
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.