Please explain the weather

Great! Seeing that threads in the “Bugs” section are being merged without adding the votes of the closed threads makes me wonder about the accuracy of the snapshots. I am aware that in an ideal world ONE thread would exits for ONE problem. But that’s far from reality. As I have pointed out in another thread regarding the “lightning in clear skies” issue (weather-related - isn’t it?) the current snapshot only lists a fraction of the real votes regarding the problem.
And for this topic, I have found 1794 votes until now, and that would make this topic #1 on the Bugs list by far:
Live Weather and Wind Readings are Not accurate (553)
Live weather is not working (416) closed on October 13th and merged with above
[Consolidated Vote] Live Weather Issues (v1.9.5.0) (323)
Live Weather Error (155)
Weather - Visibility Control (111)
WEATHER is still NOT working correctly! (68)
Live weather and live traffic not working? (65)
Live weather: No low visibility modelled - MeteoBlue Data itself seems to be wrong! (41)
LIVE Weather Issues on second flight (38)
Live Weather: ATIS does not match conditions (ex. sim shows overcast, atis reports few) (24)


No, I sincerely don’t think that this has anything to do with “prediction-based weather”, and here’s why:

The values for KTEX are consistently so far off, that this simply can’t be caused by any model they’re using. And Meteoblue has the correct set of variables on the website.

IMO, something is broken under some circumstances when the (correct) data is being injected or when the (engine based) forecast model is being applied.

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Exactly! And as i think the weather-engine is a quite complex system not so easily fixed maybe it would suffice to create an interface within the sim to extract the current (in-sim) values at any given airport for planning purposes? I would prefer real “real live-weather” though…

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You see, that’s exactly why I’m doubting that we’ll see a fix for the issues anytime soon: They don’t have to reproduce anything, they know about the issue probably since pre-alpha. It is so ■■■■ obvious.

If I you were the guy at MS/Asobo responsible for the Live Weather, wouldn’t you have checked the feature in a variety of airports across the planet yourself, before making it available to alpha testers? I’m pretty sure you would have…

I sympathize a little bit with Asobo, because I believe they are primarily a game studio, and they are building a “Flight simulator” from a gaming perspective rather than from an Aviation perspective. I can see it with their priorities and how certain issues are addressed.
Weather for example, having listened to the live streams and heard all the have to say about weather I have come to accept that the weather system we have now is considered complete from their point of view despite all the numerous omissions and errors

  • the same 3 cloud layers in the ATIS
    -the same dewpoint
    -Hit or miss with the winds etc.
    -In ability to view full weather reports of any stations before or during the flight just to mention a few.

Anybody in aviation knows the importance of accurate weather and access to that information but so far FS has been all about Visuals and very little on the core aspects of Flight.


This does not have to be repeated again and again. It is crystal clear and everyone who is involved in aviation knows that. If you could tell me which sim has the better weather, I would be very grateful.

Let me get my popcorn bag first :slight_smile:


As a real world pilot, I have learnt to really lower my expectations for FS, but when I see what they are capable of with the visuals I can’t help but hope they come right with the “simulator” part of things. :wink:


Good, but where is the better sim or weather than what ASOBO offers with Meteoblue.

You can never compare a simulation with reality. And that is also the reason why I do not understand the complaining here.

“Live weather” in the sim doesn’t match what is happening in real life. The other day I flew from South Carolina to DCA and in the sim I flew through lighting, storms, 30kts of wind, and thick storm clouds. The real weather was 20C and clear with a puff of breeze.


Well, maybe you should watch this again to understand why people are complaining…?

Why would they feed this amount of real-world data into MSFS in the first place if the didn’t want to reproduce real-world conditions?

Wouldn’t you agree that MS/Asobo set the expectations, not we did?

Wouldn’t you also agree that something is fundamentally going wrong if even the initial conditions (like you’ve seen yourself before) are completely off sometimes?

And yet, they’re still calling it “live weather”.

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Well I wasn’t aware that they don’t have it on their list of things to fix. That seems odd considering that I’ve not heard of them denying or ignoring other issues.

Hi TomL7753,
I do not know how the upvoting system works. Can you please explain how we can check that each of the upvotes on these numerous weather thread was made by a different forum members to justify the 1794 votes you counted. Thank you.


But you’ve seen their updated list? Or is there another one where the weather is still listed?

For me this is live weather within the given framework. I do not expect a military grade weather simulation.

I think the best solution will be Asobo releasing a weather injection plugin that bridges the meteoblue weather prediction data to other sims. It should be compatible with Microsoft FSX, FS9/2004, FS2002, XPlane 9-10-11, P3Dv3, v4, v5, AeroflyFS1-2, and DCS. In addition to that, we’ll need a custom METAR publish channel, so that VATSIM, IVAO, and PilotEdge can grab the exact same weather data.

This way we’ll have ultimate consistency among whole flightsim community.

Problem solved!

Look, you’re not answering my questions.

You said that you don’t understand why people are complaining. I responded by stating that MS/Asobo set the expectations themselves and that because of that fact people are complaining; because what they delivered doesn’t live up to these expectations.

If you’re happy with the current implementation, I’m actually happy for you. :slight_smile:


I’m happy with FS2020 at all, not only the weather :wink: Unbeatable. Sorry.

I’ve scanned it yes. Real weather, while cool, isn’t a big deal for me. Most of the time, if it’s too cloudy and / or rainy I’ll change it to something sunnier anyway. So… I didn’t really pick up on it being missing from the list.

There is no question that the Live Weather system is mis-handling air temperature at any high-elevation airport. I do not think this is a problem in the raw forecast data being provided by MeteoBlue - rather, it appears to be the application of a completely unnecessary correction to the forecast model temperature based on the elevation of an airport.

I believe that when Live Weather is active, the temperature reported by the airport ATIS in-game is indeed the temperature contained in the MeteoBlue forecast model for the particular airport and time.

I know many parts of ATIS are “buggy”, (especially the cloud layers), but I do think that the ATIS temperature and pressure are an accurate representation of what the MeteoBlue model is providing.

When the airport is located at sea level, the ATIS temperature and the ambient temperature (as shown on an aircraft’s OAT readout) are always identical.

But, at higher elevation airports, the ambient temperature is always higher than what ATIS reports - and the higher the airport, the greater the discrepancy on the warm side.

The problem is especially notable at KTEX, because it is a very high-elevation airport (9,070 feet). The ambient temperature will typically be 15 to 20C higher than what ATIS reports. This leads to the absurd situation of having surface temperatures of 80+ degrees Fahrenheit in October at an airport in the Colorado Rockies, when the actual temperature (per ATIS) is (and should be) closer to 45-55F.

A similar over-warm temperature bias also exists at other high elevation airports like KDEN and KABQ (both of which are over 5,000 feet), but KTEX shows the problem best.

I have a good idea what is causing this, but have no direct knowledge of how the weather system is coded internally.

When using the “clear sky” weather preset, there is a temperature correction applied based on altitude, and in this situation, an altitude correction is appropriate. With the preset, there is no temperature being injected from an external source, so air temperature is simply decreased using the standard ISA lapse rate of 1.9 degrees Celsius for each 1000 feet of altitude above sea level. This is also the scheme used in FSX/P3D and X-Plane when using a clear sky “no weather” preset.

In the ISA model of the atmosphere, the temperature at sea level is considered to be 15C. Indeed, if you select the clear sky preset in MSFS and spawn at a sea level airport like KJFK or KBOS, the temperature will always show 15C.

Based on the ISA standard atmosphere, the temperature at KTEX should be 17 degrees colder than sea level, (based on the 9,000 foot elevation).

9 x 1.9 (the ISA lapse rate per 1000 feet) = 17.1C Subtracting 17.1 from 15 (the ISA sea level temperature) gives a temperature of -2C

This is exactly what happens at KTEX when the clear sky preset is active. The temperature will be -2C, which is perfectly correct. Anyone can verify this by spawning at KTEX with the clear sky preset enabled.

Using an altitude-based temperature correction is fine when no external weather data is being injected, but it is completely inappropriate to do so when weather is coming from an external source.

What appears (to me) to be happening is that when Live Weather is active, an altitude-based temperature correction is being applied to the MeteoBlue provided airport temperature, and it is being applied in reverse. Normally (using the ISA lapse rate), KTEX will be 17 degrees colder than sea level. Instead, it appears that at KTEX, approximately 17 to 20 degrees is consistently being added to whatever Live Weather ATIS reports the temperature to be, making the ambient temperature far too warm.

This bug can be repeated at will at any time. Simply spawn at any high-altitude airport with Live Weather active. Listen to the ATIS temperature report. Note the actual OAT temperature on the aircraft display. It will always be warmer than what ATIS reports. It certainly appears that most often the discrepancy (in degrees C) will be very close to airport elevation in thousands of feet multiplied by 1.9

Again, I am almost 100 percent certain that the temperature reported by ATIS is in fact the current MeteoBlue forecast model temperature for the airport.

NOTE TO ASOBO: When Live Weather is active, no altitude-based correction should be applied to the injected temperature.The temperature from MeteoBlue for the current aircraft location should directly set the ambient temperature without modification of any kind. Terrain elevation should not be factored into the temperature equation in any way.

None of what I am saying here addresses the other “issue” of whether the forecast model temperature is “right” - it some cases it may be quite a bit different than the current r/w METAR. But, the situation is not being helped by the fact that whatever the forecast model predicts the temperature to be at a given place and time, a completely unnecessary altitude based correction is being added which always causes the ambient temperature to be too high the farther above sea level an airport’s elevation is.

@SkipTalbot upon digging a little further, it almost appears that the ambient temperature that Live Weather is providing at any given airport is an almost perfect match for the potential temperature (theta). I wonder if they are simply using the wrong temperature variable from the gridded data MeteoBlue provides? The ambient temps one sees at mountain airports is very close to the predicted theta as shown here:


I would accept sorta close to reality “live” weather if ATIS was 100% correct and if we had a way to extract weather from in-game for flight planning. Without those it is useless.

The problem is we have people in this thread that don’t care about reality and just want to look at pretty clouds that change.

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