DCS Real Weather Updater

About

This program is a simple utility meant to be incorporated into a DCS server's restart script. The utility fetches the most recent weather report (METAR) from a selected airport and attempts to make the weather conditions inside a provided mission file match the report. When configured this way, a server can run a static mission file but regularly update the weather conditions automatically. The utility can also update time of day based off the current time and a given offset if desired.

Usage

1. Create an account at checkwx.
2. Find your API key from your account details and copy it.
3. Download the latest release.
4. Extract the files in the release zip.
5. Open the provided config.json with a text editor of choice.
6. Add your API key between the quotes and configure the other settings to your liking. A description of each of the settings is provided below.
7. Save your changes and ensure the config file remains inside the same directory that the realweather.exe file is located.
8. Create or configure the mission file you want to be updated with the real weather.
9. To run the utility you may either manually run the realweather.exe, or you can use a script to automate the process. Some examples are provided in examples.
10. Enjoy automatic weather updates to your mission!

Alternatively if you prefer a more feature-full and comprehensive DCS server experience, check out DCS Server Bot. Real Weather is a supported extension and can be integrated directly with the tool.

Notes

• It is recommended that you keep a master copy of your input mission file, and then use this mission for each weather update rather than updating the realweather mission. This way your main mission stays safe in the rare event of some malfunction leading to corruption. You can accomplish this through your normal restarting script, but an example is provided in examples if you do not already have something like this set up.
• If your input mission file is not in the same directory as realweather.exe, make sure that you have an absolute path to the file in your config. However, it's recommended that you use a relative path and copy the input mission into the realweather directory as part of your server start/restart script.

Config file

An example configuration file can be found below along with an explanation of each parameter.

Example config file

{
  "api-key": "", // your api key from checkwx
  "files": {
    "input-mission": "mission.miz",      // path of mission file to be updated
    "output-mission": "realweather.miz", // path of output mission file
    "log": "logfile.log"                 // path of log file, "" disables
  },
  "metar": {
    "icao": "KDLH", // ICAO of the aiport to fetch METAR from
    "runway-elevation": 0, // elevation of runway in meters MSL
    "remarks": "",  // addtional remarks to add to METAR, for customization only
    "add-to-brief": true // add METAR text to bottom of mission brief
  },
  "options": {
    "update-time": true,    // set to false to disable time being updated
    "update-weather": true, // set to false to disable weather being updated
    "time-offset": "-5h30m", // time offset from system time
    "wind": {
      "minimum": -1,      // max allowed wind speed in m/s, negative disables
      "maximum": -1,      // min allowed wind speed in m/s, negative disables
      "stability": 0.143, // atmospheric stability for wind profile power law
      "fixed-reference": false // use a fixed ref height for wind calculations
    },
    "clouds": {
      "disallowed-presets": [
          "RainyPreset1",
          "RainyPreset2",
          "RainyPreset3"
          ], // List of weather presets you do not want to be chosen
      "fallback-to-no-preset": true, // use custom wx if no suitable preset found
      "default-preset": "Preset7" // default preset to use when no match found
    },
    "fog": {
      "enabled": true,           // set to false to disable fog
      "thickness-minimum": 0,    // min thickness of fog in meters, at least 0
      "thickness-maximum": 1000, // max thickness of fog in meters, at most 1000
      "visibility-minimum": 0,   // min vis through fog in meters, at least 0
      "visibility-maximum": 6000 // max vis through fog in meters, at most 6000
    },
    "dust": {
      "enabled": true,           // set to false to disable dust and smoke
      "visibility-minimum": 300, // min vis through dust in meters, at least 300
      "visibility-maximum": 3000 // max vis through dust in meters, at most 3000
    }
  }
}

Config Parameters

• api-key: string
  • Your API key from checkwx, should be a mix of letters and numbers.
• files: string
  • input-mission: string
    • This is the path of the mission file that you want to apply real weather to. This is typically a relative path from the Real Weather executable, but it can be an absolute path too.
  • output-mission: string
    • This is the path that you want the modified mission to be output to. This should generally be different from your input file.
  • log: string
    • This is the path that you want Real Weather to create its log at. If you do not want logging, you can disable with "".
• metar
  • icao: string
    • This is the ICAO of the airport you would like weather to be pulled from.
  • runway-elevation: integer
    • The runway/airport elevation of the ICAO configured in meters. This is used to convert cloud heights between MSL and AGL values for METAR accuracy. Using this value the METAR will report the clouds in hundreds of feet AGL. This can be set to 0 to retain the legacy behavior of reporting clouds in MSL altitudes. This value will also be used for the reference height in wind calculation if fixed-reference is false.
  • remarks: string
    • This adds a RMK section in the METAR string. There is not functional impact of this setting. It's used for customization only.
  • add-to-brief: boolean
    • If true, Real Weather will add the generated METAR to the bottom of your mission brief.
• options
  • update-time: boolean
    • Disable/enable Real Weather modifying your mission time.
  • update-weather: boolean
    • Disable/enable Real Weather modifying your mission weather.
  • time-offset: string
    • This is the offset from system time used when updating the mission time. This value should be a string such as "1.5h" or "-2h45m". Supported units are nanoseconds "ns", microseconds "us", milliseconds "ms", seconds "s", minutes "m", and hours "h".
  • wind
    • minimum: integer
      • This is the minimum wind speed in meters per second that Real Weather will apply to your mission. You can set this to -1 to disable minimum wind speeds.
    • maximum: integer
      • This is the maximum wind speed in meters per second that Real Weather will apply to your mission. You can set this to -1 to disable maximum wind speeds.
    • stability: float
      • This is the atmospheric stability number used in the wind profile power law. This is used when calculating wind speeds at altitudes other than the airport elevation. 0.143 is generally a good setting for this, but it can be configured to your liking. Larger values generally equate to less stable atmosphere with bigger difference between ground winds and winds aloft, and smaller values generally equate to more stable atmospheres with ground winds being closer to winds aloft. See the additional notes below for more information.
    • fixed-reference: boolean
      • Disable/enable using a fixed reference point when calculating winds aloft. If false, Real Weather will use the runway-elevation as the wind reference point for calculting winds aloft. If true, Real Weather will use 1 meter MSL as as the reference height for wind calculations. Generally this should be set to false.
  • clouds
    • disallowed-presets: string array
      • This is a list of all the presets you do not want to be chosen. This can be an empty list [] if you do not want to disable any presets. Available preset options can be seen in the additional notes below.
    • fallback-to-no-preset: boolean
      • If this is true, Real Weather will use the legacy weather (no preset) when a suitable weather preset is not found.
    • default-preset: string
      • This is the default preset that will be used if fallback-to-no-preset is false and no suitable preset can be found in the allowed presets. Leave this as "" to disable and use clear skies as the default.
  • fog
    • enabled: boolean
      • Disable/enable fog when apply weather to your mission.
    • thickness-minimum: integer
      • This is the minimum fog thickness in meters that will be used when applying fog to your mission. This must be at least 0 and less than thickness-maximum.
    • thickness-maximum: integer
      • This is the maximum fog thickness in meters that will be used when applying fog to your mission. This must be at most 1000 and greater than thickness-minimum.
    • visibility-minimum: integer
      • This is the minimum visibility in meters that will be used when applying fog to your mission. This must be at least 0 and less than visibility-maximum.
    • visibility-maximum: integer
      • This is the maximum visibility in meters that will be used when applying fog to your mission. This must be at most 6000 and greater than visibility-minimum.
  • dust
    • enabled: boolean
      • Disable/enable dust when applying weather to your mission.
    • visibility-minimum: integer
      • This is the minimum visibility in meters that will be used when applying dust to your mission. This must be at least 300 and less than visibility-maximum.
    • visibility-maximum: integer
      • This is the maximum visibility in meters that will be used when applying dust to your mission. This must be at most 3000 and greater than visibility-minimum.

Additional notes:

• For more info on stability, see the following 1, 2, 3.
• Fog thickness is not reported by a METAR, so the thickness in DCS will be a randomly chosen value between your configured min and max.
• Presets you can disallow are presented in the following table. Please note the lowest cloud layer's altitude may vary since Real Weather will try to match it to the METAR as best as possible.

Preset Name	Cloud Layers
"Preset1"	FEW070
"Preset2"	FEW080 SCT230
"Preset3"	SCT080 FEW210
"Preset4"	SCT080 SCT240
"Preset5"	SCT140 FEW270 BKN400
"Preset6"	SCT080 FEW400
"Preset7"	BKN075 SCT210 SCT400
"Preset8"	SCT180 FEW360 FEW400
"Preset9"	BKN075 SCT200 FEW410
"Preset10"	SCT180 FEW360 FEW400
"Preset11"	BKN180 BKN320 FEW410
"Preset12"	BKN120 SCT220 FEW410
"Preset13"	BKN120 BKN260 FEW410
"Preset14"	BKN070 FEW410
"Preset15"	SCT140 BKN240 FEW400
"Preset16"	BKN140 BKN280 FEW400
"Preset17"	BKN070 BKN200 BKN320
"Preset18"	BKN130 BKN250 BKN380
"Preset19"	OVC090 BKN230 BKN310
"Preset20"	BKN130 BKN280 FEW380
"Preset21"	BKN070 OVC170
"Preset22"	OVC070 BKN170
"Preset23"	OVC110 BKN180 SCT320
"Preset24"	OVC030 OVC170 BKN340
"Preset25"	OVC120 OVC220 OVC400
"Preset26"	OVC090 BKN230 SCT320
"Preset27"	OVC080 BKN250 BKN340
"RainyPreset1"	OVC030 OVC280 FEW400
"RainyPreset2"	OVC030 SCT180 FEW400
"RainyPreset3"	OVC060 OVC190 SCT340

Contributing

Interested in helping to improve this project? Please see the contributing guide for guidelines on making suggestions, opening new issues, or contributing code. Thanks for your interest!

Enjoying this project?

Please consider starring the project to show your support. If you would like to get more involved, read the contributing guide to see how you can improve DCS Real Weather. This started as a small personal project and has grown to a small user base over the past couple years. Feel free to spread the love by posting about DCS real weather or by sharing with friends. Also join our small Discord community for support, announcements, and camaraderie. For those interested in supporting the project financially, please see the "sponsor" button at the top of the page for options. Thanks!