No more minecraft clouds in XP12.1 which is great however the new weather engine in XP12 is unfortunately a step backward. I know it is human nature to disagree and dismiss this claim immediately but please read on. This is unfortunate as the XP weather engine has a distinct advantage over MSFS weather engine.

I am a RW pilot and meteorologist. I have analysed the current XP12 weather engine to the XP12.1 weather engine in detail. The difference in plain to see and very noticeable. 

The new weather engine now gives more weighting to metar data than GFS data. On the surface, you might believe this is an improvement. However, metar data especially in Europe only provides cloud cover up to 5000 feet. There maybe and frequently is cloud cover above 5000 feet which is not reported in the metar. The end result now are rings of fewer or no clouds above 5000 feet around metar stations when in reality there is significant cloud cover...which the current weather engine realistically injects according to GFS data. Currently in XP12.9, the interpolation of metar and GFS data is realistic when compared to actual satellite images (in the current XP).

Now with the updated interpolation in XP12.10 between metar data and GFS data...rings of unrealistic fewer clouds especially but not exclusively at mid and higher levels are dotted around (where the metar station are located) in what should be thick overcast frontal cloud layers (and is the case with the current XP12.9 weather engine). 

Why change the weather engine when in fact the current blend of metar and GFS data is perfect? If it ain't broke why fix it. 

48 minutes ago, Falconjet112 said:

 metar data especially in Europe only provides cloud cover up to 5000 feet.

True

48 minutes ago, Falconjet112 said:

The end result now are rings of fewer or no clouds above 5000 feet around metar stations when in reality there is significant cloud cover..

Not true afaict, Its a blend from multiple sources including regional GRIB coverage

METAR: LYBE 011130Z 21008KT 170V240 CAVOK 29/12 Q1011 NOSIG

TAF: LYBE 011100Z 0112/0212 23012KT CAVOK TX29/0113Z TN14/0203Z TEMPO 0114/0118 30008KT

They do run it from their own servers now, so there is plenty of opportunity for "disconnecting from reality" if their weather sources are down - nothing anyone can do about that.

But given I've had it rain on me in the sim minutes before it actually starts raining outside, this is gonna need a _lot_ more than he said she said for any changes imho.

 

Edited June 1, 20242 yr by mSparks

1 hour ago, Falconjet112 said:

Now with the updated interpolation in XP12.10 between metar data and GFS data...rings of unrealistic fewer clouds especially but not exclusively at mid and higher levels are dotted around (where the metar station are located) in what should be thick overcast frontal cloud layers (and is the case with the current XP12.9 weather engine). 

If you have thouroughly tested it, you could discuss the matter with XP developers. For a starter, maybe report it as a bug using the bug report page, in a concise and clear way.

2 hours ago, Falconjet112 said:

No more minecraft clouds in XP12.1 which is great however the new weather engine in XP12 is unfortunately a step backward. I know it is human nature to disagree and dismiss this claim immediately but please read on. This is unfortunate as the XP weather engine has a distinct advantage over MSFS weather engine.

[...]

METOFFICE here too 🙂 and glider pilot for more than 4 decades 🙂

Your remark comes in sintony with a post I made one of these days where I mentioned exactly that same effect, but at the MSFS2020 forum, because both MSFS 2020 and XP12 appear to be plagued by that same "blend" problem between aloft / forecast data and METAR, specially places of the World, and indeed most of Europe, away from mountainous regions, are good examples.

One of the major impacts this has on both default XP12 and default MFS weather is that when I go searching for gusty weather spots to use with FSIPANEL and train tricky approaches in one of my 3 Airbuses for MSFS I end up starting from a position say, around 4000' where the winds are actually tame... 

As the descent starts the changes come, but in a rather unrealistic way, where the gusting and actual wind directions and variability only become closer to those reported by the METARs most of the times bellow 1000 AGL !!!

I recall same happened last time I tried the same scenarios in XP12.1 beta

Edited June 1, 20242 yr by jcomm

Yes, for me it seems to be the same - I think they rather gave the METAR the “authority ”!
My test example is “LOXT” (not always occupied and not always METAR data available) - before the 12.1 version the clouds were often correct (of course not always possible in the SIM) - unfortunately, after the update, if there is no data available - clear weather is simply displayed - so so-called METAR bubbles are apparently created here - unfortunately, exactly the “wrong” way - just like MSFS.
The look is of course much better - but you also see less incoming fronts !!! 😔

 

On 6/1/2024 at 6:30 AM, jcomm said:

because both MSFS 2020 and XP12 appear to be plagued by that same "blend" problem

It could instead easily be said that they are plagued by the same "user" problem. The weather depiction can be very realistic at times. The candy is dangled in front of the children's eyes. It's natural to want that 100% of the time without realizing what goes into it. So we scream until devs are forced to use METAR even when it doesn't align with the prediction GRIBs. And then we scream again. And they must certainly wish they could push us into that chocolate river....

 

On 6/1/2024 at 6:30 AM, jcomm said:

METOFFICE

In other words, what we really need is for you to retire early from the metoffice and set up post as a custom human-based weather generator for our simming drug! :)

Y'all weather experts really need to file bugs with Laminar if you want to get any deficiencies ironed out.

This is perfect example of what I mean! (Click on the links).

Massive unrealistic clear holes around METAR stations which should be filled with cloud. Cloud decks above 5000 feet (not reported by METAR stations) are not represented in the sim even though in reality these cloud layers DO exist (as shown by clouds surrounding the circles of clear sky!!) and verified by satellite imagery.

You can even see the circle of cloud surrounding the blue sky in the sim. Totally unrealistic.

The older generation XP12 weather engine blended the GFS GRIB data appropriately with METAR data. The new weather engine does not! It is a step backward and very disappointing.

https://ibb.co/NS5TWj5

https://ibb.co/kSkJYG0

 

Edited June 8, 20241 yr by Falconjet112

11 minutes ago, Falconjet112 said:

This is perfect example of what I mean! (Click on the links).

Massive unrealistic clear holes around METAR stations which should be filled with cloud. Cloud decks above 5000 feet (not reported by METAR stations) are not represented in the sim even though in reality these cloud layers DO exist (as shown by clouds surrounding the circles of clear sky!!) and verified by satellite imagery.

You can even see the circle of cloud surrounding the blue sky in the sim. Totally unrealistic.

The older generation XP12 weather engine blended the GFS GRIB data appropriately with METAR data. The new weather engine does not! It is a step backward and very disappointing.

https://ibb.co/NS5TWj5

https://ibb.co/kSkJYG0

 

My suggestion to the laminar devs was they dont modify cloud coverage given by the grib files above the dew point altitude, and do what they have been doing 12.1 beta with the metar below that.

Is it ok for me to share these pics with them?

26 minutes ago, Falconjet112 said:

The older generation XP12 weather engine blended the GFS GRIB data appropriately with METAR data. The new weather engine does not! It is a step backward and very disappointing.

https://ibb.co/NS5TWj5

https://ibb.co/kSkJYG0

Report it as a bug here, please:

https://www.x-plane.com/x-plane-bug-report-form/

Add your screenshots to your bug report, they are very explicative.

Unfortunately this is often how constant progress is made. You keep improving things, then break them with other improvements so you can improve again.

I was shocked when I discovered that things I tried to report as bugs in 12, and which were ignored (like tiles of scenery not loading in time though the harddisks remain idle) had been reported as fixed, years ago. In X-Plane 11!!

 

This discussion has been going around and around since P3D and MSFS etc years back. The issue of translating weather reports/forecasts into recreating simulated weather. The limitation of METARS is precisely that they are a meteorological report and the reporting is focused on the airport weather - after all that is the critical interest for the flight crew's operational decision making. 

The limitations are spelt out in any met document that will tell you that the CAVOK criteria will result in cloud above not being reported - as for winds - very few but some do actually report a 2000 ft AFE or 4000 ft wind on some metars where they get the data from a local met station (radiosonde anybody) because that is significant but it is not common. Same with cloud could be OVC above the 5000 ft level but still reported CAVOK - the metar will just not give you the cloud amount - and let us not also forget the rounding rule for observations that is the largest amount is reported first so other stuff may be there and not reported. All the rest comes from forecasts and those forecasts are dependant on the scope of the forecast - a small local or geographical area or a large geographical area, below F180 or above. So you just cannot get a 100% accurate picture to present in the sim. I think they do a pretty good job with what they have. 

Then again time is a bust as well, forecasts are issued for long periods of validity (about 8 hours) and will not be reissued unless there is signficant change or differences - lost count of the number of times when I was flying the weather forecast was spot on and others where it was fine and good yet the forecast was doom and gloom. You live with it but keep a keen eye on the metars for the minimums (Cloud and Vis) because that will tell me if I need to plan or conduct and instrument approach and whether I need an alternate as a result. 

Now if I was a VFR driver then what concerns me is completely different - I want less cloud and good vis and the ability to traverse an area visually and legally (distance horizontaly and vertically from cloud). If the forecast is non VMC then you either do not go or wait! But you would get your chops busted if you set of VFR into NON VMC forecast weather - even if you could say but it is not. Ultimately and it is in all the rule books the PIC is responsible for assessing whether the vis and cloud in flight for all the above reasons!

Now squaring this up for simulated flight is a might big ask! I think it is pretty word not allowed good really for a representative experience. 

Finally as an example of how good - looks like Laminar nearly have rainbows sorted. This picture was at Avalon in Victoria Australia. Coincidentally in my local area and same sort of weather low cloud with breaks towards the sun setting - I saw rainbow in real life and well this is pretty close to being a rainbow: