# Unexpected behaviour of wind layers

Hello,
Yesterday I tried setting 2 wind layers as follows:

1. Ground level: wind speed: 2 knots; gust speed: 100%; frequency: 35 secs; wind direction: 270
2. 5000 feet: wind speed: 40 knots; rest of settings, same a layer 1

What I saw happening is that at ground level the wind was 2 knots without (notifiable) gusts, as expected.

Then during the climb, the wind speed started gusting between 2 knots and a higher speed, depending on my altitude. So, e.g. when at 2500 feet (half way to the second wind layer), the wind speed was gusting from 2 to 20 knots, until I reached 5000 feet and there the wind speed was continuously gusting from 2 to 40 knots. Also it was gusting at a very high frequency (not 35 secs, but closer to 3 secs).

I would expect the wind speed to gradually increase from 2 to 40 knots while climbing to 5000 ft, but not gusting between speed at ground level to the speed defined a 5000 ft.

I did not submit a ticket to Zendesk, because it could also be my misunderstanding of how wind layers work.

Did anyone else notice this problem or is it my misunderstanding of how wind layers work?

Michiel

We have a base speed. 40kts at 5,000 in your example,
We have a gust speed. Also 40kts at 5,000 in your example.

Because winds always change speeds, the base speed should vary from some lower number to some higher number. So does a 40kt base wind speed mean from 2kts to maybe 50kts? I;'d expect something like that because when we talk wind speed it is an average over time.

But then we have gusts. If the base speed is varying then what actually is a gust? The UI gives a clue with frequency. It is a fast change in speed over a short period if time and it is added to the base speed active at the time of the gust. But, the UI forces a 50% gust speed. If the base winds can already move over a 2kt to 40kt range then why can’t gust be zero?

So, I wonder if the base speed is static and the gust is actually how MSFS makes the wind move. If so it is a very simplistic model.

Now with what you’re saying. Simplistically, the wind speed in a different layer has nothing to do with the wind speed in another layer in real life. So if that is what you’re seeing then I’d think it is a bug but, going by what I said it could just be a poor implementation of the base wind speed variability so it actually maybe on purpose. It depends on how you numbers look if you select a different ground level base speed.

I’ll try to remember to use my app to log the winds during a flight over a range wind layers tomorrow and see what I can see. You got me interested on working it out.

The frequency value has never done anything sensible or intuitive AFAICS.

Interesting. My own interpretation was that gust of 100% means a gust wind with exactly the speed of the base wind. So, no gusts.
Gust of 120% would mean gusting to 48 kts (in case of 40 kts base wind) and 50% would mean gusting from 20 kts to 40 kts (base wind speed).

Hello, sort of (un)related to the discussion here but has anyone noticed that there (appears) to always be a 180 deg. wind shift at around 500 ft. or so? This is in Live Weather by the way, not sure about the canned stuff.

Could just be my imagination but some testing appears to be bearing this out. Was just curious if anyone else was seeing similar.

Q. If this is the case could it explain why the sim is assigning the opposite runway to AI traffic? Just a thought.

Thanks

Personally I haven’t noticed this before. How high/thick is this wind layer?

Sorry for the delayed response, life gets in the way. After doing some more invest. I do not always see the change so it may be ‘correct’. The layer seems to change around 500 t0 1000 agl when it occurs.