AWO Current Competency: Class A

Cloud Observations

Assessment Criteria

1. Identify the following cloud types:

   • Stratus

   • Cumulus

   • Towering Cumulus

   • Cumulonimbus

   • Stratocumulus

   • Altocumulus

   • Altostratus

   • Nimbostratus

   • Cirrocumulus

   • Cirrostratus

   • Cirrus

2. Recognise characteristics specific to each cloud type above

3. Indicate the standard heights of the low, middle and high étages based on Australian climatology

4. Indicate the composition of the cloud types ie. warm water droplets, supercooled water droplets, ice crystals

5. Identify typical signatures of various cloud types as indicated by satellite images, synoptic charts, ceilometers, aerological diagrams

6. Determine the atmosphere’s stability characteristics and explain the corresponding effect on cloud development

7. Determine an approximate convective cloud base height given surface temperature and dew point temperature

8. Use ceilometer data to assist in determining height of the cloud base

9. Use an aerological diagram to assist in determining the height of the cloud base

10. Use knowledge of spot heights of local features to assist in determining the height of the cloud base

11. Convert a cloud base height relayed via a pilot from height AMSL to height AGL

12. Describe the basic operating principle of a laser ceilometer

13. Describe the limitations of the ceilometer sky condition algorithm output with slow moving or stationary cloud, and when the sky is dominated by convective cloud.

14. Describe the issues associated with the ceilometer sky condition algorithm output when multiple cloud layers exist

Visibility Observations

Assessment Criteria

1. Define meteorological visibility by both day and night

2. Determine from a ‘visibility scenario diagram’ the following:

   • Minimum Visibility and Direction

   • Prevailing Visibility

3. Give examples of the meteorological factors that will reduce visibility

4. Describe the use of visibility markers to assist with determining visibility

5. Describe the basic operating principle of the FD12 forward scattering visibility meter

6. Describe the limitations of the visibility meter data when the transparency of the atmosphere is not uniform

Weather Observations

Assessment Criteria

1. Define the following precipitation phenomena:

   • Drizzle

   • Rain

   • Snow

   • Hail

   • Snow Grains

   • Small Hail

   • Snow Pellets

   • Ice Pellets

2. Match the types of precipitation associated with particular cloud types

3. Determine precipitation intensity using both rate of fall and visibility cues

4. Describe the appropriate use of the following descriptors:

   • Shallow, Patches, Partial

   • Drifting

   • Showers

   • Thunderstorm

   • Freezing

5. State the cloud type associated with thunderstorms

6. Define the following phenomena:

   • Mist and Fog

   • Smoke, Dust, Sand, Haze

   • Volcanic Ash

   • Dust Devil

   • Squall

   • Funnel Cloud

   • Duststorm and Sandstorm

   • Thunderstorm

7. Recall the visibility reduction associated with fog phenomenon

8. Interpret data from a weather watch radar to assist with weather identification

METARAWS/SPECIAWS Coding Procedures

Assessment Criteria

1. Decode an Aerodrome Weather Report (both METARAWS/SPECIAWS and METAR/SPECI)

2. Describe the differences between messages with and without manual input

3. Determine how visibility is reported in an Aerodrome Weather Report given a ‘visibility scenario diagram’

4. Define Runway Visual Range (RVR)

5. Decode the RVR component of an Aerodrome Weather Report

6. Recognise that RVR is only approved for use during low visibility conditions characterised by fog or mist

7. State the distances from the aerodrome reference point used to determine whether phenomena is occurring at the aerodrome or in the vicinity for Aerodrome Weather Report purposes

8. Recall the technique used to report more than one form of precipitation occurring simultaneously in an Aerodrome Weather Report

9. Explain the requirements for the inclusion of a thunderstorm either at the aerodrome, or in the vicinity, in an Aerodrome Weather Report.

10. Recall any visibility requirements for reporting phenomena as present weather in an Aerodrome Weather Report, where applicable

11. Determine which clouds are included in an Aerodrome Weather Report given a series of cloud observations

12. Recall the equivalent okta cloud amounts for FEW, SCT, BKN and OVC in an Aerodrome Weather Report (METAR/SPECI)

13. Explain the technique used to report Cb and TCu with a common base in an Aerodrome Weather Report

14. Define the terms CAVOK and NSC

15. Understand the term ‘25nm Minimum Sector Altitude’

16. Identify when CAVOK or NSC will be coded given a series of observations

17. Recall those phenomena that are applicable to recent weather reporting

18. Determine which phenomena are to be reported as recent weather given a series of observations

19. Describe the format for reporting windshear in an Aerodrome Weather Report

20. Understand the term 'Highest Alternate Minima'

21. Use ASH Table 6.2 and 6.3 to determine which SPECI criteria thresholds have be crossed given a series or observations or reports

22. Recall the procedure to issue a clearing SPECI following an improvement in weather conditions