Let's clear up clouds

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There has been a lot of discussion lately about the interpretation of Live Weather clouds. Let me be perfectly clear…

I agree there have been some issues with the visibility/ground level clouds in the last couple weeks.

Now that that is out of the way.

As seen in the update to SU7 currently in testing most of the issues with cloud cover/visibility have been addressed. It seems there may be some issues with very low cloud being converted to fog when in fact it should be low cloud, but that too may be resolved by the time the update goes live.

What I have been seeing throughout this is a lot of confusion over what is realistic. I am still seeing multiple posts pointing out that clouds are way to low, or that an overcast description in a METAR is displayed as scattered or broken.

First let’s discuss base levels. When an airport reports, “BKN010”, what they are seeing is cloud base at 1000 feet above ground at their location. As we can see in most instances airports are generally built on flat ground. Flat ground is not usually found on a hill top. The result? Most airports tend to be built on lower ground than the surrounding terrain.

As you approach the airport in this example, it is very likely that the 1000 foot clearance between the cloud base and the ground will actually be less than that. In some cases, a lot less! My local airport is surrounded by 700 foot hills. If the ceiling is low and you are approaching VFR it is very possible to grossly break minimums even though the airport is VMC.

So, the clouds surrounding the airport may, in fact, wind up with bases that are below ground level. This is not unrealistic. Clouds do not care how high the hills are. They form at a given height depending on temperature, pressure, humidity NOT hill height.

Next let’s examine the way we describe sky conditions. What is overcast? In layman’s terms, overcast means, “I can’t see any blue”, - from my point of observation. The sky condition descriptors we use are cumulative. In other words, I can have 2/8s scattered, stacked in 5 layers of cloud, thousands of feet apart. When you stand at the airport and look up, you see an overcast sky. As you climb in your airplane you may be seeing 5/8 broken at 2000 feet and be 2/8 scattered by the time you are at 4000.

Read your METARs carefully. “SCT070 BKN030 OVC060”, does not mean that there is a solid layer of cloud at 6000 ft. It just means that the guy making the report couldn’t “see any blue”. As you depart on your flight you may find 4/8 as you climb above 4000’.

I have looked at a lot of screen shots lately. Most of them claiming to show clouds on the ground, or scattered clouds when the METAR says OVC. I will admit that the “Above Mean Sea Level vs Above Ground Level” bug was real. It is fixed now. Yet I keep seeing pictures posted by users that have the beta installed, still claiming clouds on the ground.

It is possible for clouds to envelope hills and for 700’ ceilings to look really low. I am aware that the weather generation in the sim is still not perfect. I only ask that if you want to join in on the bug reporting, PLEASE do your homework first. Confirm the METAR and post it along with your screen shots. Don’t fly 2500’ above the cloud base and post pics confirming the clouds are on ground. Do not park on the tarmac and take shots of the cloud base 5 miles away. These show us nothing.

If you suspect the clouds are too low at the reporting station, indicate the altitude of the airport, fly over the airport AT the METAR reported cloud base altitude. Show us a screen shot that shows your altitude.

It isn’t that we don’t believe you. It is how we collect empirical, irrefutable evidence of a bug so that someone in a position to fix it can actually confirm the error.

A shot taken from a drone 1000 feet above an aircraft flying at 5000 AGL looking down at puffy cumulous clouds with 900 foot bases IS a bit hard to interpret.

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I have been testing and following others testing the Live Weather model in the SU7 update. So far the reporting for the beta has been a mess. I have pretty solid reading comprehension, but I cannot follow half the reports.

There seems to be a lot of confusion over the whole METAR thing. To begin with, going for a flight while comparing the weather to a METAR is ridiculous. A METAR is a ground observation at a fixed location. By its very nature that makes it historical. Even if you get the METAR at the moment it is published the observation was “in the past”. It is also, only accurate AT that station. You cannot use a METAR to compare weather along a route.

Combine that with the fact that if it is OVC then there is no mention of additional cloud layers. The observer can’t see what’s up there. Could be clear skies. Could be massive CBs building. Anyone’s guess. Then mix in the continuous movement of weather systems and there is absolutely no chance that you can fly for ten minutes in any direction and expect a METAR to be accurate. If it is, it is only by coincidence.

To have users comparing historical, localized, observations against a dynamic weather engine that is attempting to blend a forecast model with that historical data to produce a simulated smooth representation of real world conditions just seems ludicrous to me. What is a bug and what is weather forecasting magic?

I understand that many here are not pilots. Most pilots would never plan a flight using METARS alone. The only way you can get a picture of the expected weather along your route is to use all the information available. Back in the ‘old’ days that would mean a trip to the FSS and getting a weather brief.

I would always start with an Area Forecast, then Terminal forecasts, upper winds forecasts all combined with actual observations at the reporting stations along my route. From that and a solid understanding of how weather works and some great input from the weather guy at the FSS you could build a picture of what to expect. "What to expect", not a carved in stone, “this is what the weather is”.

If the picture out the window is different than what I expected then I deal with it. Adjust accordingly. Make some calls along the way and find out what the new expectations are.

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The Meteo Blue weather data is our global weather. In specific locations, encompassing usually less that a 10 mile radius, we have observed data that the sim is trying to inject into that global model. Either you will have an accurate “bubble of weather” surrounding the station and forecast weather in between, or you will have a smooth transition between the two which will make the whole package, both more accurate and more dynamic. But you cannot have both.

How can we test the accuracy of forecasts and dynamic weather as a community of flight simmers?

We can’t.

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Well, we could.

If the sim made all current weather data driving the visualisation for your location available via an API. But they have said again and again that they will not open the weather system up to 3rd party developers. Even on a read only basis. That is a real shame.

Meteoblue are a great company who do very good weather modelling (and I’m biased). But that is all it is, a model. Then throw in Asobo, probably under pressure always from Microsoft, and you get the stupid bugs from lack of understanding in using numerical prediction model output. Like top of atmosphere temperatures (again). Then try to shoehorn observations into a forecast model space like METARs and you’ll cause trouble. Add the regional differences for METARs, like the USA and their statute miles visibility, again with no understanding implemented in sim to give everywhere haze/mist, within the area of an airport. And don’t get me started on cloud base height, AMSL vs. AGL bug.

I’d love to see Asobo/Microsoft just admit that they don’t know what they are doing most of the time and ask for help from specialists in APPLIED meteorology in the aviation space. Numerical predication isn’t applied meteorology. Flight simulation should include applied meteorology, but in this case there appears to be a disconnect.

Just about every weather bug I’ve seen since launch was obvious within a few minutes of flying the sim after a new update. I’m not even a pilot, but I do know weather.

It is frustrating. And no one party, as far as I can see, is to blame. But it does need sorting out if this sim is to be taken seriously going forwards.

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First cross-country navigation lesson I learned when getting my pilots license: you will spend an hour looking at forecasts, trends, checking winds, calculating wind speed, ground speed, heading offsets and direction for every leg of your flight, only to have it be obsolete by the time you get in the air.

Thank you for this write up. Hopefully it helps folks who don’t have a grasp on aviation weather understand why what they think they should be seeing, and what they are actually seeing is not a simulator issue. It’s
a real-life flying issue.

If anything, the fact that the observed weather doesn’t match the METAR published 45 minutes ago only make the simulator that much more realistic! :laughing:

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Thanks for taking the time to write and post this, I was wondering how long it would be before something like this emerged - you’re right and it needed saying.

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Fundamentally, you are absolutely right. However. You check the METAR and you see there is wind from X direction, you start the sim, you find wind from the opposite direction at half speed. Yes, the weather might have changed. But when the METAR refreshes, the wind is STILL as it used to be. So the sim was wrong, or Meteoblue data did not match reality.
TAFs (where provided) can help, but would be interesting to find out whether those are being leveraged in the sim or ignored.

is not necessarily a simulator issue. As I explained above. And that’s exactly what happened to me today in a short flight from TNCM to TNCS.

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In general, I agree with your sentiment and overall testing methodology of showing the proof. I would add - create videos to show the full picture as it helps as well.

But, there are few points I don’t agree with

  1. OVC 6000 in this scenario is an 8/8 sky obscuration for that layer. The ASOS (which is the most common method) actually is evaluating 3 separate layers and based on what I understand, the 3rd layer in this case is OVC within that 5 miles of the reporting station - Page 24 of this adds more - Link

  2. If 1. above is true - this means that if the Sim is presenting those layers, I do expect that at 6000 ft AGL, I expect to see within the 5 NM of the airport OVC conditions (8/8 sky obscuration). Today, that is not happening at a consistent level within the sim.

  3. Using METARs and forecast together -

The implementation needs to improve. But the concept is not bad. There are days when I fly IRL - the METAR and sky conditions don’t match. I’ve seen days where 3 miles West of the airport the sky is clear but above airport is BKN / OVC, but 90% of the time, they are pretty close and based on 21 years of flying - the weather doesn’t change that fast to make the METAR completely invalid. On days where it does happen, I can totally understand the sim not being able to model / support that. But for majority of the times, it should work.

In theory if the implementation of this concept works - within the 5 SM (with some extra buffer, say + / - 2SM) the weather should be reported METAR or close to it - so if I’m going from say KPAE to KSEA

KPAE would be METAR - 5SM out would be forecasted weather (this is where there needs to be a transition of sorts) and KSEA would be METAR - 5SM upto 12K ft (given that is the limit of METAR). The rest should be forecasted from Meteoblue.

The implementation is not done right today and needs to be improved, but I do believe this is a good model to follow. Maybe there is a path for the forecast model to be sync’d more often vs. 2 times a day - I don’t know if this is an option and would solve for the prior challenges.

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The biggest concern, for me, is the inconsistency with live weather – meaning, several times I’ve launched and it’s nothing but clear skies… yet if I use Rex Weather, which uses METAR as well, it’s more accurate, so Asobo/MS has to figure out how to keep live weather going… too many outages.

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Great suggestion! Seriously.

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I bet some of the MS Devs wish they had just added 5 or 10 user weather choices to choose from and never introduced “Live World Wide Weather” into the sim. hehe

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You obviously misread my question.

Weather sciences are based on probabilities. We have amassed a staggering amount of weather data over the years. Massive amounts of computing power is dedicated to looking at current conditions, comparing observations with historical data, running predictive algorithms, all in an attempt to improve the chances that our predictions are at least relatively indicative of what the earths weather system is going to throw at us.

The ONLY weather that is accurate is that which you see above you and feel on your face. You may think you can stand in your back yard, look up at a big black cloud and reliably state, “It is going to rain”. You can’t. You can say, “It looks like it is going to rain”, and you would be right. Just because it looks like it will, doesn’t mean it will. It may eventually, somewhere, but not now and not here.

If the experts can’t “predict” the weather with billions of dollars of computers and more billions of dollars worth of satellites and petabytes of historical data, what makes you think that our little community can look at our screens and say, “the weather displayed on my computer is wrong according to the METAR published 30 minutes ago”?

I live three miles from the end of the runway of our local airport. I have a friend that lives about five miles from the other end. She drove to town this morning in low visibility and light snow. At about the same time I went let the dogs out and marveled at the crisp, clear sky. I also noted a hard, solid line of cloud, silhouetted by the false dawn. Looked to be just over the airport. I didn’t check but I can bet that the METAR was very different than what either I saw or what she saw. Was the METAR wrong?

I know I have written a lot of words in this thread. It is because we, as MSFS pilots want a weather system as close to reality as possible. Unfortunately, those with no more knowledge about weather mechanics than what they learned from their local tv weather forecaster, seem to want to advise Asobo on what is accurate in terms of generating an accurate, predictive weather model. We do not have the expertise!

Yes, we can point out that the wind in the sim doesn’t match the ATIS. ATC is giving us wind that is not being modeled. ATIS says it is clear and we can’t see the terminal from the ramp. There is a 300 degree temperature jump. These are obvious errors in coding that need to be reported.

When it comes to cloud layers that don’t match the METAR or the visibility does not match what I see out the window, we need to understand that weather is NOT predictable to the degree some of us seem to think it is.

If you want an accurate, realistic, dynamic weather model in your flight sim, you will need to defer to the experts. If you want your sim weather to perfectly match the VATSIM weather model then we will need to have another preset in the sim for that. Weather based on METARS is NOT an accurate, realistic, dynamic weather model.

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I am not sure I understand what you are stating in point 1.

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While it is possible that I have misunderstood the sky conditions rating for my entire career, it looks like the link you provided is saying the same thing I am. 3/8 + 7/8 + 4/8 = OVC.

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I have access to huge amounts of weather information when I fly, but we still look out the window or go for a walk outside before making a decision to fly or not.

I think the other thing that is being missed is that weather can be very different even one to two kms away, one side of the airport will be blue sky and the other pouring rain in real life. These are the decisions that need to be made every day.

Like you said, if its too predictable it is not real life.

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Of course you can.
Who would you like to ask?

If that was directed at me, you can click on my avatar for details, but in summary, I am a professional pilot with a specialization in meteorology. After 30 years of extreme bush flying in some of the most remote and inhospitable places on our planet, I have a fairly good grasp of what the earth dishes out for weather.

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Do you know when this update will go live, So that with the clouds

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I don’t think anyone knows the answer to that question. It does seem that Asobo is committed to getting the update right. It is uncommon for them to update an update of an update in such short order.

I could guess, but kind of like weather prediction, it would mean nothing without supplying probabilities.

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LOL. “Asked and answered, Counselor.”
:+1:

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@ willisxdc: You make a lot of valid points and as a whole, the SU 7 beta is a step into the right direction.

But there ist one meteorological situation that is depicted very unralistically now: calm winterly inversion weather with a low overcast blanket.
This is the most common weather in Nov / Dec here in middle Europe. In reality the blue sky is not visible, visibility is degraded, but mostly > 10 km, the cloud base is low (500-1000 ft) and looks totally uniformly grey. The upper boundary of that blanket mosty is also very flat. As winds are calm and sun doesn’t warm the ground, this situation is almost static for hours and days, so no fast changes from one METAR to the next.

What do we get in MSFS (also in SU 7 beta)? Often there are patches of blue visible, and clouds are most often ridiculously towering cumuli which one would expect on a hot summer day.

Moreover (and this is wrong from the beginning of MSFS), lighting at low sun angles (which we have in winter for several hours a day) obviously does not take cloud cover into account: the mist glows in yellowish and orange colors, obscuring your view towards the (in RL invisible!) sun, which would be appropriate if the sun wasn’t blocked by a dense overcast layer. But there is no such thing as a colorful sunset on an overcast winter day! The color of the sunlight before sunset must not automatically change to orange regardless of the cloud cover - this is plain wrong.

So these two things need to be fixed for the weather to be more realistic.

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Are you running the latest public beta?

What you are describing is being worked on as we speak. The SU7 weather update was apparently intended to improve on the simulation of low cloud. The result was the clouds ending up much lower than intended. The visibility model was also changed and resulted in unrealistic low vis conditions at nearly all airports.

The update beta has improved the low cloud/vis model significantly. I expect there will be further improvements coming soon as well.

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I agree that for overcast day, the sun still shines through the clouds too much