Question about weather, real vs simulated

Hi community

I was wondering, with all the new aditions about solar radiation and alterations based on temperature, sun and water, does this mean that if I put live weather but change the time of the day now the weather is different from the live one? I mean, if now is 23C but I suddenly change the weather to 22:00, the temperature and solar effects are recalculated and the conditions change or remain live?

I was wondering how do you keep live weather accurate if you dont use live time and date. So, if I approach an airport and downloads the latest METAR will be weird if my time of the day is different as the effects on the ground could differ from METAR.


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This question can only be answered by a developer working for Asosbo and is in touch with this topic !!!
I have my personal ideas how I would approach the weather simulation, but there are certainly other approaches which possible would be fine. The weather simulation and it’s continious improvement certainly keep developers busy in future for years and will be frequently discussed by the community.

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As Titanic says only a dev would know for sure. But my take is that if you use LIVE weather then you get METARs. Those METARs are used “near” airports but elsewhere the weather is generated by MeteoBlue. In the past I’m sure Asobo said they don’t do historic weather so if you choose an earlier time, it isn’t going to give you the weather at that earlier time.

About weather.

  1. MeteoBlue is a forecast using a model updated N times a day. I doubt it is updated more than a few times per day, weather calculation is expensive computationally and I doubt all sensors report in real time.
  2. A METAR is a current observation. Forecasts are very good these days but they often differ from actual weather noticeably.
  3. METAR only exist in specific airports. And they cover a relatively small area.
  4. The lower altitude then the more the forecasts is probably off as far as winds are concerned because of the surface features have a bigger effect.

So given that, a lot of the issues people have are:

  1. The forecast and METAR are different causing jumps in weather changes. This will occur in three dimensions.
  2. When a new forecast is made the weather has to change in the sim to the new data. This can cause a big jump.
  3. Where there is not METAR available, the sim has to use the forecast which is why I think a lot of airports I frequent in the game do not use the normally main runway.

Personally I don’t care if weather is accurate to real world. I only care that the appropriate runway is used and consistent for everyone. So consider flying where you can see all people, not just those that choose to by “online”. Those people not in the online group could by flying with completely different weather I think. That could explain why aircraft are often using the wrong runway. I’ll have to check that.


If you mean the winds reported from METAR? Winds in a METAR is a meassured average windspeed in 10 minutes interval at 10 meters height. That means in that period of time the wind has varied all the time IRL. That average of wind Asobo injects in a constant rate in the sim. Then they change that constant wind to be varied in the sim with help of the sun to make that average windspeed feel organic. In su 10 we will also get reported/forecasted gusts. Thermals they added in su9 is never meassured/reported in a METAR. Only the horizontally winds. Asobo added simulation of thermals depending of how much sun heats up ground.

IRL the winds also differ from the METAR more or less all the time. But the runway in use doesn’t differ all the time. It’s set depending on what the average winds direction is or other factors depending on airport location. I would like to know in detail what factors decides runway in use IRL?

I found this:

Air traffic controllers consider a number of things when deciding which runway to use. These can include:

  • number and type of aircraft operating at the airport
  • length of runway(s)
  • weather conditions (both present and forecast) - including wind velocity and gradient, wind shear, wake turbulence effects and position of the sun
  • availability of approach aids in poor visibility conditions
  • location of other aircraft
  • taxiing distances, including availability of taxiways
  • braking conditions.

Some airports also have ‘preferred runway’ systems. This means that if wind conditions, workload and traffic conditions allow, a particular runway will be used to move traffic as efficiently as possible while reducing the noise impact over residential areas.

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