nhasan
commented
12 years ago Hi,
I don't think you are correct. According to Federal Meteorological Handbook #1, which defines the METAR format:
5.5.1 Units of Measure and Resolution for Wind: Wind direction and speed shall be reported in the body of all observations. Direction shall be reported in tens of degrees with reference to true north and speed shall be reported in knots (see paragraph 12.6.5).
Both METAR and TAF always report wind direction with reference to true north and need to be converted to true north.
On Sun, January 22, 2012 12:48 pm, pseizinger wrote:
Very nice product, however I noticed that your decoding of weather information for an airport is giving the wrong information for the winds. While it is true that all winds aloft are provided in True direction, that is not the case for wind observations and wind forecasts for an airport. In those cases the winds are provided in Magnetic direction.
It is a little thing and any pilot reading the information should know this, but it can be misleading for the uninformed or novice.
Reply to this email directly or view it on GitHub: https://github.com/nhasan/Airports/issues/17
Nadeem Hasan (nhasan-at-nadmm.com) GPG Fingerprint: 7141 0B1C 9CAF 624D 307F F8EF 6C0C 753E DD3A 0F53
Very nice product, however I noticed that your decoding of weather information for an airport is giving the wrong information for the winds. While it is true that all winds aloft are provided in True direction, that is not the case for wind observations and wind forecasts for an airport. In those cases the winds are provided in Magnetic direction.
It is a little thing and any pilot reading the information should know this, but it can be misleading for the uninformed or novice.