Thermals, Up & Downdrafts - Realism Update/ Airmass Simulation

  • basic weather / cloud / temperature / surface based thermals, up & downdrafts are now integrated (Simupdate 9), they gonna get improved in future updates, a big CFD simulation (20km around the aircraft) is planned/ currently in research

  • thermals should get longer lasting updrafts which are surrounded by turbulent downdrafts

  • Weather features such as turbulence, cloud types and shapes should be emergent - they should be result of proper airmass simulation

  • broken ridge lift which goes up forever needs to be fixed

  • Wave & Convergence lift missing

  • Thermals shouldn’t be related to general windspeed and there shouldn’t be an general altitude strength limit (because these are planned updates to make ‘‘things more comfortable’’, but they are completely unrealistic)

  • the up & downdraft strength limitations seems to be lifted a little bit, however not completely, there is still lots of room before we come close to what is possible in reality

  • related to this topic I created a new and more specific wishlist thread
    Realistic Dangerous Weather - Physics Simulation
    If you want more realism in that regard, leave a vote right there as well

  • there should be an integrated world map option to see where we have lots of updrafts / good thermal weather similar to the Meteoblue map


Sadly the topic got closed… but we can continue to discuss in the newly opened thread right here:

Thermals, Up & Downdrafts - More Realism Updates

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Although Kinetic Assistant is a great tool and has opened up a new world - as a glider pilot i deffenitly wait for real wether flying conditions beeing reproduced in the sim. Asobo AND Community : Thanks for all which is possible already- and keep going .


I agree 100%, I really hope Asobo starts implementing/improving the up/down drafts and thermals.
But there isn’t even a timeline for that, that’s why I really hope this wishlist post goes into the top 15.

Otherwise we will probably have to wait at least a year.

Asobo says everything is already implemented, but I never noticed or saw any thermal and the up/down drafts are so limited that they are also unusable.

Sadly the kinetic mod is the only way to use any glider at this moment.
I’m thankful for that, but I’m also gonna wait for the ‘‘natural’’ thermals and unfiltered up/downdrafts.


I just re-watched the Jan 2021 Developer Q&A twitch and the discussion of thermals seems totally disconnected with what’s actually happening in the sim.

There is neglible thermal activity in the sim.

Thermals are not ridge lift - ridge lift in MSFS seems ok.

Thermals are not turbulence - turbulence in MSFS seems ok.

Thermals not appearing over seas and large bodies of water is not an issue - no-one tries to soar a glider over large expanses of water.

Thermals “limited to 1000 feet per minute” is a complete non-issue - that would be a GREAT thermal.

The issue is there are no thermals in MSFS. Every Cumulus cloud is there because air rose until it reached the condensation temperature. At that point it actually speeds up a bit (the condensing vapor releases a little energy). You can fly under hundreds of Cu’s in MSFS and will not encounter any thermals of any strength. In fact you can fly under a CuNim descending gently in dead calm, which in real life would be terrifying because you would be being lifted up into the cloud almost faster than you can dive out of it.

In case I haven’t made this clear enough, this is nothing to do with the sea, winter, mountains, ridge lift, or turbulence or a thermal strength cap or experienced RL glider pilots being too dumb to find the thermals in MSFS.

A simple test would be someone, somewhere, manages to actually gain height in a glider on a zero wind day (to eliminate the ridge lift), which RL glider pilots are pretty much certain to on any summers day almost anywhere in the world.

When we were first hunting for thermals, the turbulence caused by the excessive gust system (now dialled down) was enough to make you think MAYBE there was thermal activity but you couldn’t hook into it, but then we learned how to turn the gusts off and these phantom thermals disappeared. I’m guessing Asobo have been fooled by their own gusts to believe the thermal uplift is actually there, or maybe are assuming “thermal” means “updraft” so ridge lift counts as a thermal.

Note that ridge lift (wind blowing up a slope) works all the way down to near ground level (accepting the wind will slow down due to friction with the ground) i.e. you could theoretically ridge soar twanging the hillside trees with your wing. This might make landing on a hillside airstrip tricky but isn’t normally an issue on flat airfields.

Thermals cannot magically ascend vertically out of the earth - there’s a slower zone at the first few hundred feet where the warm air collects to form a narrower rising column of air which then rises several thousand feet.

Microbursts are a wacky extreme process of this operating in reverse. A large parcel of unstably cooled air descends rapidly until it smacks into the ground. This, thankfully, isn’t common like thermals, but can occur when there are large airmass temperature differentials (i.e. it’s “stormy”).

“Thermals limited to 1,000 feet per minute” - yeah sure.


I’ve not experienced and actual thermal in game yet so I’m pretty sure they don’t understand what a thermal is. Though surely some of the pilots must be getting an idea, it was part of my courseware. The turbulence we often got too much of was “thermal” related. But in no way are we getting the vertical updrafts we expect. So in that respect, thermals are partially modeled.

I’m wondering if the duration of these 1,000 fpm thermals are the issue. If they only ever happen for fractions of a second then it just becomes turbulence.

Now for something boring. My favorite thermal story that I think illustrates the point.

I’m flying in an Evektor SportStar from Murray Bridge to Aldinga. It is a fairly calm summers day and quite bumpy (thermal based turbulence) and I’m 1,000 feet below class C. Then all of a sudden whoosh, within a few seconds I’ve climbed like a rocket and I’m 200 feet below class C. I’m having to hold a noticeable pitch down attitude to keep me from busting class C. Then just as quickly, it disappeared.

I was telling one of the other pilots at Aldinga and she and her instructor had the same thing and she couldn’t believe how much nose down she had to be to maintain level flight while she was in it.

I’d never had it during training so it surprised the heck out of me. Bad sink is often a lot more noticeable (to non-glider pilots), especially on final :slight_smile: Oh, and once on takeoff that had me literally not climbing while I wondered if my wheels were hitting the tops of the trees. I had to turn crosswind to avoid the hill in front of me, I’d never paid more attention to a coordinated turn before. On downwind it was fine. Fortunately I’d only had that once too, that was in a J160.

Ok, two stories… But “exciting” experiences we can’t get in MSFS until thermals and sink are properly implemented. Like before, Asobo will say “we don’t want to do that because simmers will think it is a bug”. Then teach them darn it! Is it a sim or a game!


Alex has done a good job on Kinetic Assistant injecting thermals into MSFS.

The basic idea is not that complex - small areas are chosen where if the user aircraft enters that area you add an upward component to the forces acting on the aircraft. There can be improvements like what shape the thermals are, how strong, how they move with the wind, the profile of updraft speed over time, whether you tune the thermal strength to the type of land beneath it. Extra marks for recognising that thermals can line up to the wind, forming ‘streets’ of Cu’s.

But thermals are much much harder to find on ‘blue’ days. RL glider pilots take full advantage of the clouds on Cumulus days marking every thermal. The issue is never whether there’s a thermal under the Cu, only whether the updraft will have petered out by the time you get there.

Asobo have the internal sim information of where the Cu’s are, but this is not available via any development API, so at the moment Kinetic Assistant cannot align the thermals with the clouds which is a major handicap.

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I don’t know at which point they decided to go for the up/down draft limit, but I searched for an older video on youtube where somebody tried ridge soaring with a DV20 and he’s gaining some altitude it’s awesome.

Thanks to the limit something like this is currently not even possible with a glider mod, it’s really frustrating…

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Are there any alpha tester out there who maybe could share their experience with the ‘‘non limited’’ up and down drafts from last year?

Would be really interesting to know if it really was that bad or uncontrollable before they decided to go for the unrealistic limited version.

There were never realistic thermals/convective updrafts in the alpha or release from my experience with both. The video linked to above is demonstrating orographic/terrain based lift, which is a different process than thermals and convective updrafts. Ridge lift is still not limited as far as I can tell, and I’ve been able to ridge soar with any aircraft and a strong enough wind.

My thoughts are that this isn’t as simple as adding a slider. Thermals need to be realistically modeled, which they probably aren’t yet. Same with convective updrafts and clouds, which so far is probably more of a visual effect than a realistic weather effect. Simply throwing a bunch of thermals in there and adding a slider is going to create a great big mess just like we have with the clear air lightning we’re still experiencing, and overzealous icing effects. If the devs said they had them, but had to limit them, I bet it was because they were so wacky and unrealistic they couldn’t include them in a release, not because the newbs simply wouldn’t understand what was happening.

It’s definitely a feature I’m voting for and want to see implemented though. The proper time and effort needs to be put it into it, however. Franky, it was kind of an oversight in my opinion to release this beautiful recreation of the Earth and not put in a glider with realistic soaring capabilities.


I had to rewatch the first aerodynamics feature discovery video, he really said:

…the airflow gonna match the clouds… We have all the up and down drafts which gonna match the actual weather…

(starts at 08:52)

but the only thing you will get there are small turbulence, no real up or down draft anywhere besides the terrain based ones. You can fly through the biggest cumlus clouds with the smallest GA Airplane and sing ‘‘if you happy and you know it clap your hands’’ without any problem.

  • terrain based up/down drafts = working
  • cloud based up/down drafts = non existent
  • temperature based up/down drafts = non existent
  • thermals = non existent

Thank you for your feedback, I’ve changed the topic name and description.
Instead of asking for a ‘‘realism slider’’ we should ask for the implementation of cloud based up and down drafts / thermals itself.

It becomes more clear that this is completely missing instead of ‘‘tuned down’’.


Yes, microbursts please!


Sadly there was no word about thermal and draft implementations in the last Q&A so I think any improvement is pretty far off.

Maybe the main focus is to keep it as simple as possible for the xbox release and many million casual playing people, we simmers gonna be left behind for probably a year.

Which is sad, because imagine proper thermals and drafts with the upcoming Top Rudder Just103Solo:


‘’…we need more visualisations, also for debug…’’

I mean in the last Aerodynamics update video they pretty much showed a very good visualisation.

Still don’t understand why we don’t get at least the possiblity to play with the unrestricted up and down drafts. As expected the Top Rudder Just103Solo (and any other airplane) feels like on rails because of that.

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If you want weather improvements, also leave a vote here:
Glider, sailplane, soaring, please!

If the glider release getting prioritised, the weather improvements getting prioritised too.
Because the Gliders doesn’t work with the currently non existent thermals, up and down drafts.

Therfore we have good news:
The status of the topic has changed to Under Investigation ( = the team is currently looking into the wish)


Indeed… the 71 votes here should be added to Glider, sailplane, soaring, please. That’s the big one.

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Or add the 700+ votes right here and we have 2 topics in the top ten which support each other :wink:

I voted here too :grin: but I hope a lot of members will see our links and click Vote in the main thread about this subject . Mods won’t change anything about votes, we’ll have to add votes. Nice to see there are 71 potential votes here ! The subject is still alive ! I would love to have thermal upward airflow and be able to do ridge soaring… and an official sail plane, properly supported by the Flight Model. Sail planes are airplanes too…

This thread aims for realism in general.
Thermals, proper up and down drafts are a must for realistic aviation for every airplane.
So I’m asking for improvements in this context.

This is not another glider thread, but since gliders would definitely benefit the most from it I linked the glider topic in the main post to not split any votes in two :wink: .

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