Types of Observations For Aviation Weather

Question 1

What is an Observation and what are the different types?

Answer 1

• Observation is a snapshot in time at a particular time and place.
• METAR (METeorological aérodrome report)
• SPECI (Special Aérodrome Report)
• ATIS (Automatic Terminal Information Service)

Question 2

What is a METAR ? What is a SPECI?

Answer 2

• METAR is a routine report issued at half hourly intervals

- SPECI is a special report issued if there is a significant improvement or deterioration in the weather

Question 3

What is a weather observation made by?

Answer 3

• Automatic weather stations (AWS)
• Approved observers
• ATC officers in the case of ATIS

Question 4

What does CAVOK mean?

Answer 4

• No cloud below 5,000 ft or Minimum Sector Altitude whichever is higher.
• no CB or TC at any height.
• Visibility > 10 km
• No significant weather

Question 5

What is used to indicate an element of the AWS is not available ?

Answer 5

//

Question 6

What do two // refer to in Metar and Speci?

Answer 6

Present weather

Question 7

What do four //// refer to in Metar and Speci?

Answer 7

Visibility

Question 8

What do six ///// refer to in Metar and Speci?

Answer 8

Cloud

Question 9

What does NDV mean ?

Answer 9

No directional visibility from transmissiometer

Question 10

What does NCD mean?

Answer 10

No cloud detected

Question 11

What is AWIS?

Answer 11

Aerodrome Weather Information Service (AWIS)

Question 12

What is WATIR?

Answer 12

Combines AWS information with info from airport operator

Question 13

What is wind direction references from in ATIS? What about AWS?

Answer 13

• Degrees magnetic for ATIS.

- Degrees true for AWS.