Introduction
The purpose of metars script is to deliver reliable weather information. According to Wikipedia METAR weather report (METeorological Aerodrome Report) is "predominantly used by pilots in fulfillment of a part of a pre-flight weather briefing, and by meteorologists, who use aggregated METAR information to assist in weather forecasting." In addition to showing data directly from a METAR station this script also displays "feels like" (wind chill) temperature for static winds and gusts as explained in the Wind chill Wikipedia article ("The standard wind chill formula").
METAR weather stations are typically located at airports and defined by four-letter station codes. The four-letter METAR station data is based on ICAO codes and locations along with their codes can be found in the ICAO airport code Wikipedia article.
i3blocks configuration
Configuration sample:
[metars]
interval=2100
METARSSTATION=EFHK
METARSURL=https://tgftp.nws.noaa.gov/data/observations/metar/stations/{}.TXT
METARSENABLEMENTS={ "temperature": true, "dewpoint" : false, "feelsLike" : true, "wind" : true, "pressure" : false, "visibility" : false, "windDirType" : "icon", "useInverseWind" : false }
METARSCONFIGS={ "temperatureUnit" : "C", "temperatureSym" : "°C", "pressureUnit" : "HPA", "pressureSym" : "hPa", "speedUnit" : "MPS", "speedSym" : "m/s", "distanceUnit" : "KM", "distanceSym" : "km", "precipitationUnit" : "CM", "precipitationSym" : "cm"}
Configuration option interval
METAR stations are usually updated every 30 or 60 minutes. This example specifies 2100 seconds (35 minutes).
Configuration option METARSSTATION
This is the four-letter ICAO airport code. It will be used as part of METARSURL.
Configuration option METARSURL
This URL is used when fetching the METAR weather data. This string must include "{}", replaced by the script with METARSSTATION.
Configuration option METARSENABLEMENTS
These options specify what information is shown on the line. This is a JSON string and each key and value needs to be inside double quotes except for booleans that need to be specified with lower case "true" and "false".
Configuration option METARSENABLEMENTS/temperature
This option commands the temperature information to be shown.
Configuration option METARSENABLEMENTS/dewpoint
This option commands the dew point information to be shown.
Configuration option METARSENABLEMENTS/feelsLike
This option commands the wind chill information to be shown.
Configuration option METARSENABLEMENTS/wind
This option commands the wind information, both static and gusts along with their direction to be shown.
Configuration option METARSENABLEMENTS/visibility
This option commands the visibility to be shown. Visibility is diminished during bad weather conditions and over 10 kilometer visibility is usually described as "10 km".
Configuration option METARSENABLEMENTS/windDirType
This option specifies the wind direction type. Three options are supported. Option angle commands the direction to be shown as angles in clockwise direction. Option text commands the direction to be shown as 1 to 3 letter compass style letters. Option icon commands the direction to be shown as graphical arrow arrow symbol.
Configuration option METARSENABLEMENTS/useInverseWind
This option modifies the behavior of the windDirType option by rotating the direction 180 degrees. The safest option is to leave this setting as false so that it follows the official wind direction measurement style (described in Wind direction and Wind vane Wikipedia articles). If this option is false its meaning is "wind is from that direction", if it is true its meaning is "wind is to that direction". Inverse wind direction is sometimes used in graphical notation where the arrow represents the wind itself.
Configuration option METARSCONFIGS
These options specify the fine tuning of elements set as visible with the METARSENABLEMENTS options. This is a JSON string and each key and value needs to be inside double quotes except for booleans that need to be specified with lower case "true" and "false".
Configuration option METARSCONFIGS/temperatureUnit
This option specifies the temperature unit of python-metar. Currently supported values are F (Fahrenheit), C (Celcius) and K (Kelvin).
Configuration option METARSCONFIGS/temperatureSym
This option specifies the type of symbol or text to be shown on the line after the temperature value.
Configuration option METARSCONFIG/pressureUnit
This option specifies the barometric pressure unit of python-metar. Currently supported values are MB (millibar), HPA (hectopascal) and IN (inch of mercury).
Configuration option METARSCONFIG/pressureSym
This option specifies the type of symbol or text to be shown on the line after the barometric pressure value.
Configuration option METARSCONFIG/speedUnit
This option specifies the speed unit of python-metar. Currently supported values are KT (knots), MPS (meters per second), KMH (kilometers per hour) and MPH (miles per hour).
Configuration option METARSCONFIG/speedSym
This option specifies the type of symbol or text to be shown on the line after the speed value.
Configuration option METARSCONFIG/distanceUnit
This option specifies the distance unit of python-metar. Currently supported values are SM (miles), MI (miles), M (meters), KM (kilometers), FT (feet) and IN (inches).
Configuration option METARSCONFIG/distanceSym
This option specifies the type of symbol or text to be shown on the line after the distance value.
Configuration option METARSCONFIG/precipitationUnit
This option specifies the precipitation unit of python-metar. Currently supported values are "IN" (inches) and "CM" (centimeters).
Configuration option METARSCONFIG/precipitationSym
This option specifies the type of symbol or text to be shown on the line after the precipitation value.
Other configuration options
Other related options are command and separator_block_width but these can be defined outside the blocklets.
Behavior
Clicking the metars status line causes the status line to be updated and raw METAR updated status to be displayed with libnotify (notify-send). This behavior requires libnotify package to be installed, possibly also package dunst or any other similar option. The title bar clicking behavior reacts to left, middle and right buttons but may be configured to any number of buttons. The most essential package for this script is the python-metar package, installed with "python pip python-metar".