Welcome Guest. Sign in or Signup

3 Answers

Metar abbreviation signification

Asked by: 5807 views , ,
General Aviation

In the Metar and TAFs weather reports, we find pretty often the A02 and A01 symbols that, according to the lexical means:

Ao1: Automated Observation without precipitation discrimination

Ao2: Automated Observation with precipitation discrimination

ok, but what does this really mean ?  Sounds to me that a report with A02 won't mention if either rain or not will be present. Is that right ?

 

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

3 Answers

  1. Best Answer


    snowpilot on May 20, 2014

    Not much help…but here is says that AO2 has the ability to determine if the precip is liquid or frozen.

    http://www.hf.faa.gov/weatherdecisionguide/downloads/AutomatedWeatherObservingSystems.pdf

    Below is a non-FAA document that describes the operation of the unit

    http://www.ventureairllc.com/awos.html

    Go about half way down the site

    +1 Votes Thumb up 1 Votes Thumb down 0 Votes



  2. Bidochon on May 21, 2014

    The second link was really useful. Thanks snowpilot.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes



  3. Wes Beard on May 23, 2014

    Sometimes we don’t get enough information from standard FAA sources. Here is another government source “Office of the federal coordinator for Meteorological Services and Supporting Research” that goes into much more depth about weather stations and the associated reports.

    http://www.ofcm.gov/fmh-1/pdf/FMH1.pdf

    Page 85 of the manual has the definition of precipitation discriminator. It is a sensor, or array of sensors, that differentiates between different types of precipitation (liquid, freezing, frozen).

    It also has information about wind direction and velocity and the reported value. I didn’t know that the reported winds were a two-minute average of both direction and wind speed. If the high and low for each are greater than a certain value that information is also included. Very interesting to me. Definitely not an instanteous value like I was taught in pilot school.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.