Please make METAR optional till optimized

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21

It sure can be. The weather can change quite a bit with no special report being issued. I’ve watched stations update hourly with 90 degree swings in the wind direction. If the wind speed isn’t high enough or the direction not changing fast enough, they might not issue an update. Other reported criteria may not be considered significant enough to warrant an update like changes in sky conditions, ceiling or visibility to levels that aren’t critical. The numerical model might actually be more accurate in such instances, even if it’s a forecast generated hours ago.

Stations may also have known biases and error due to instrumentation issues and limitations. What’s cool is many numerical models actually take this into account when ingesting data so that the forecast isn’t corrupted as a result. Stations where the temp is known to be off by 10 degrees get filtered, otherwise you see weird spikes and blips in the model output.

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22

Anything can be wrong. But setting aside outlier cases like that, what’s more likely to be accurate at a given time: a direct observation that’s issued at least once per hour and more frequently when conditions dictate, or a computer’s best guess that’s updated every 12 hours (Meteoblue is only updated twice a day)?

The whole reason they incorporated METARs in the sim in the first place was that the Meteoblue weather depictions were often severely inaccurate, right?

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You’re right that the METARs, the few bits of weather they’re tracking, are more accurate in general than numerical models. But it’s not just outlier error cases. It really depends on the situation. When changing weather is occurring, which is pretty much everywhere, you will always see noticeable lag in the METAR, even when special reports are issued. The METAR is old as soon as it’s released because the weather has already moved on. And after an hour the weather can be markedly different. I stare at screens for my job where METARs are overlaid on top of radar and visible satellite, and you can tell when the METAR is old because the station observations no longer match what you’re seeing on the other feeds. It’s most noticeable when there’s a front moving near the station, where the model is trying to get the timing right on that front, but the METAR is reporting conditions from an hour ago. If the model is right on that timing, blending in METAR information will actually give you a less accurate picture. We wind up using the METARs not to get real time reports, but more for verification purposes for what the models said the weather should be doing, awhile ago, and still have to interpolate or use forecasts forward from there to get currency

I think a lot of people are hung up on the idea the METAR is the real weather. It was the real weather. It was a tiny bit of real weather.

If the numerical models were severely inaccurate, they wouldn’t be useful to Meteoblue’s customers. There’s uncertainty and error of course, but they still have valuable skill in prediction. Instead, the model has gaps where it’s incapable of showing highly localized or specific types of conditions. The goal of the METAR injection was to try to fill some of those holes, and hopefully also improve on some of the error.

But you’re still mixing old data (METARs) with wrong data (numerical forecasts). Both are increasingly diverging from reality. It’s a lot harder of a problem to solve now than it used to be on decades old solutions that were blending much more coarse and basic weather information such that it really didn’t matter if it was using hour old fragments.

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24

It seems like you’re trying to debate the point, but you end up agreeing with me in your last paragraph, by pointing out that a METAR is a direct observation but the model data is likely wrong ;).

Sure the METAR can lag a fast weather change until a SPECI is issued, but it’s still the “official” weather at that airport, and thus as long as a sim (any sim) is using METAR- based weather depiction, we’re all seeing the same weather on VATSIM etc. There’s no other way to achieve that across multiple sim platforms. (It also makes real-world flight planning and EFB tools like Foreflight usable with the sim, where purely using model data would not.) And the large majority of the time, that weather will closely match actual conditions because rapidly changing conditions aren’t the norm. Besides, a model that was last run 9 hours ago isn’t going to be any better at nailing the timing of a rapid change, if it accurately forecasts the change at all.

The value of the model (in real life and the sim) is that it provides a large-scale forecast, while METARs are specific to small areas but are at least direct observations (though there’s no reason not to incorporate TAFs too). But these areas (airports) are the ones that matter most for any sort of organized flight simming, like on the networks.

The right approach seems to be what other weather injection systems like Active Sky have done for years now - use model data for general conditions, refined near airports by METAR data. Asobo just needs to smooth out the transitions and limit the popping, but this should be doable (since systems like Active Sky have been doing it).

25

As you say, METAR are most important for airports and for organised flying on online networks.

Unfortunately in its current implementation the transition between airport weather and the weather model covering the rest of the world needs improvement and as not everyone is flying on online networks this is a throwback for the vast majority of users to give a better compatibility for a small frsction of the community.

Noone is asking to pull the METAR implementation. It is great it is here,it is fantastic that online networks should now be more enjoyable. But we should not forget the other simmers either and the title of my post says it quite clear: please make it optional till optimized

So it is not about taking it away from you, it is about leaving it for you but giving me the option to deactivate it for myself.

Of course this depends on the way it is technically done and if a separate on/off switch for the newly added METAR injection can be done.
This can only be answered by the devs, though, as the Wearher API is still not available.

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26

Solid points and fair enough.

27

you have that backwards… the forecast model is run by the supercomputers twice a day, so it can be up to 12 hours old. metars are usually less than an hour old.

(and im going by what one of the weather geeks here has told me, 12 hours – on the meteoblue site it says every 24 hours)

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True, but the model is including a forecast to dynamically fill the gap between the updates and therefore gives a smoother transition than a static METAR that remains the same and then changes abruptly when updated.

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but the resolution of the model is only 1 hour as well. so its still just smoothing between 1 hour points.

you can smooth metars as well.

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Of course you can. That’s what you call a Model.
You Interpolate real World data and calculated the missing values in between.
Thats what I mean by “optimization”.

Right now, the sim does not smooth it properly

It doesn’t even load more than 1 METAR right now.
Best observed in area with high density of airports, lile eg. Los Angeles.
Fly over the City and observed the weather Co stolz changing instantly while flying through the METARs of different airports.

I appreciate the implementation of METARs and their will to improve it.
But for now, I would prefer to go without METAR for visibilty and clouds.
I dont mind temperature, pressure or Winds changinging spontanously, it is the visual weather poppig I dislike…

31

I’m curious, are you a VATSIM user? If so, did you find the pre-SU7 weather unsuitable for VATSIM flying?

I don’t fly on VATSIM, never have, but I’m curious which aspects are the most important to be accurate across the board for flying with online networks.

32

I agree with this as well. Although, improvements could have been made to the transitions for temp, pressure, and winds. But if I had a choice, I’d rather deal with harsh transitions for the aspects of weather that aren’t visual.

33

That’s right, I agree with the ultimate goal here of using some METAR information to improve the weather depiction. But what I caution against is relying on the METAR as a definitive source for recreating realistic weather depictions due to its inherent shortcomings. Despite it being an observation, because it is time lagged and a coarse fragment of information, it has the potential to degrade Flight Simulator’s weather, not improve it.

When I fly on PilotEdge or pull up a METAR on ForeFlight flying for real, I expect the weather to resemble that METAR, to be valid enough for safe operations. What I don’t want to see in Flight Simulator is the rest of the weather around the airport compromised in order to exactly match an hour old METAR. I’d rather have a realistic, plausible weather experience with some inaccuracy and occasionally much inaccuracy than to be constantly dealing with bubbles of weather around airports and unrealistic transitions between flat weather scenes.

Real life weather doesn’t match the METAR, the sim weather shouldn’t match the METAR either. Ideally, when the numerical model based volumetric weather is implemented to its full potential, it is close enough, most of the time, that you just use your normal aviation weather sources like you normally would. It won’t match up exactly, but that’s the way it should be.

ActiveSky is great for what it does, improving the weather depiction of decades old platforms. It’s not working with global volumetric weather though, in which weather is a location in a continuous fluid mass to and through which you fly. It’s instead fading scenes of weather in and out around the aircraft like changing the backdrop on a stage production. ActiveSky got the blending down only because of this. They didn’t have to deal with the new methods Flight Simulator uses to generate weather. When the weather model isn’t performing its best or because part of Flight Simulator is broken or incomplete, some folks clamor for a return to this outdated and unrealistic solution from yesteryear, where now the volumetric weather system has to be potentially compromised or diluted to appease those who are used to having it a certain way.

Yes, please add the METAR information. But only if you can do so without making the sim behave like ActiveSky or REX, and without spoiling the volumetric weather. This was marketed as one of the simulator’s core features.

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34

In short they should open up the SDK to developers. Or get activesky on board as a partner it could seriously help them in my opinion

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35

Right, but which METARs are getting smoothed? If it’s 10:50 here, the sim might still be using the METAR that was issued at 9:50. Blending in another METAR means going back to 8:50. Meanwhile, the forecast model has the forecast for both 11:00 and 10:00 so it can just interpolate to produce current weather at 10:50. If you blend the METAR with the forecast model, are you blending an observation from 9:50 with the forecast for 11:00? You could certainly improve on this, but It gets complicated quickly, and I suspect it’s the video game devs at Asobo that are doing this blending, not the meteorologists at Meteoblue.

What bothers me is that the sim shows big weather systems moving across the landscape. Yet the weather at airports is now frozen for an hour. So you’re going to see generic sky condition clouds blending with the passage of a frontal boundary? It seems like a big compromise.

I agree, but Asobo has said repeatedly they’re not going to do it. But we could keep begging for it and maybe they’ll change their minds.

There are models that run every hour with forecasts for every fifteen minutes, that have the spatial resolution such that the weather is different at opposite ends of the same runway. That’s better than a METAR at that airport even. Augment that with satellite and radar. I’d easily pay a subscription fee if a developer like ActiveSky could deliver volumetric weather on that scale.

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36

It seems that you’re still focusing on outlier cases where the METAR is not accurately describing current weather at an airport, because of rapidly changing conditions. I’m not saying this can’t ever happen, but how often in real life flying have you seen real conditions at an airport differ dramatically from the last observation, and how long does that condition last before a SPECI is issued?

Conversely, how often do you see differences between actual conditions and a model whose last run was up to 12 hours old?

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37

Yes, the pre-Su7 weather was problematic for online simming. Ideally on a network, you want pilots experiencing similar conditions. You’ll never have conditions perfectly synced of course, but you want things close. Wind needs to be similar so everyone agrees on the correct runway for instance. Ceiling and visibility should be close so that ATC knows what level of approach services pilots require; does everyone need a CAT III or can most pilots accept a visual from the downwind? Etc. When pilots are flying with dramatically different weather, it gums things up for everyone.

And yes, while I only briefly used MSFS prior to SU7, I often saw weather that bore no resemblance to current METARs; IMC while field reported VMC, winds favoring the wrong runway etc (even though supposedly winds had been METAR based for a while?)

Again, I’m not saying the current implementation is perfect. They have smoothing to do. But it’s sure a step in the right direction. I also have no argument against making it optional of course; options are good. I just wouldn’t want to see it done away with and a return to the often-flawed purely model-based weather.

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38

yeah something like that. my main point was theres no reason the local weather needs to instantly jump from one metar to the next, you can transition it out over 15 minutes, blend it with the forecast as you mention (weighted by reliability?), etc. there are people a lot smarter than me that i’m sure can figure it out. but at least most people seem to agree that a combination is probably the best way forward and not just using one or the other (forecast vs observations) exclusively…

39

Most times I fly? It depends when and where you fly, and what conditions you consider dramatic. Morning preflights in the Midwest and Plains during the warmer months and I know the winds have already veered and increased from what the METAR is reporting. Clouds are always moving in and out, so sky conditions are always in flux and not updated if they don’t significantly impact operations. Yeah, the METAR is still safe to use for getting a plane on and off the ground, but the weather can look dramatically different, have a significant impact on your flight a short ways away from the field, and also be noticeably different on the runway too. I know in the afternoon I’m going to be battling convection. I can see the conditions changing, the towering cumulus building. I don’t want a storm to suddenly fade in overhead in the sim because a special update was issued.

My point here is that the METAR is last hour’s old news. It’s a stepped function lagging behind with a few fragments of significant weather at a point location. It’s a minimum amount of info for safe flight, not a great source for constructing a comprehensive depiction of weather.

Now we’re mixing that with a dynamically changing, continuous volume of a less accurate best guess at the current weather. If the forecast is correct and the weather in flux, the METAR will inherently degrade the weather depiction because it’s lagging behind out of sync and contains limited information. The model could potentially show the winds veering and increasing continuously, the clouds moving on and off the field correctly in the right direction. A METAR based depiction will only ever show static weather with jumps to what the weather used to be. A bubble of time locked 1D weather inside of dynamically changing 4D weather.

It’s even worse if there are special updates issued more frequently than hourly, because now the hard jumps and transitions are much more noticeable.

And conversely, if the forecast is wrong and the weather is stable, now you’ve always got to deal with jarring transitions as you fly away from that accurate weather at the field. I’d rather deal with some issues in accuracy than issues where the weather isn’t behaving realistically.

Pre SU7 Live Weather worked pretty well on Pilot Edge most of the time. There were times where it was off of course, but the controller or the pilot could just make their own observation and adjust accordingly.

SU7 started injecting more of the METAR in verbatim and it was literally breaking flights on Pilot Edge. You’d be in VMC with miles of visibility in one moment, and the next moment the lights were switched off and you were in low IMC. They’ve fixed a lot that, and we’re making progress in the right direction, but the METAR based weather is still creating bubbles, weird transitions, popping. It’s probably as good as we’re going to get. A real fix to this is going to involve building an entirely new model for Flight Simulator, which is way outside the scope of this project. I just wish they’d focus heavily on delivering the promised next gen model based weather. In response to the outcry from releasing half finished and half broken builds, they’re instead regressing to the safe, reassuring (yet archaic and unrealistic) arms of METAR based static weather scenes. The numerical forecast model can give a realistically dynamic experience because it understands the underlying processes of how and why the weather is changing. The METAR simply can’t. You want to trade realism for accuracy, it’s probably personal taste and dependent on the type of flying you do. I’d rather the online controllers work directly with the discrepancy in Flight Simulator’s model based Live Weather.

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40

The online controllers are working traffic on about 5 different simulators. Whose weather should they work directly with? That’s the whole point; they use real world weather because it’s the only baseline that everyone can use in all sims.

I’m sorry, but you do not see significantly different weather than the METAR “most times you fly”. I wouldn’t ordinarily be contradicting someone else’s personal experiences, but this I do know for certain, after 29 years and over 15,000 hours flying all over this continent. There are times the SPECI issuance hasn’t kept up, but these ARE outlier cases. Look at it this way: very worst case, a METAR is an hour off. The Meteoblue model can be 12 hours off. It’s just a model. There’s a reason forecasters don’t use only model data to create real world forecasts. A model can easily blow an obvious occurrence like a frontal passage by hours.

Weather is also not static at airports in the sim now; where did that idea come from? You can sit and watch the weather roll by. I watched the tower at Medford fade in and out of visibility while I sat on the ramp the other night. You can fly two instrument approaches to the same runway, miss the first, and get in on the second, all with the same METAR. There’s absolutely variability.

Yes, they need to smooth the transitions. To my mind, that’s a minor issue compared to being able to use Foreflight or my work Jepp and WSI apps for sim flight planning and nav.

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