higher wind settings Rough Seas

[too-cool]

How do I create Seas as in the attachment, with out excess winds/turbulence, what should my setting be for weather?  Thanks TC

Rough Seas.pdf

[razo+r]

You can only directly influence the magnitudes of the waves by setting an appropriate wind setting.

[Dieselmadness]

I will say I’ve noticed that in order to get the pitching deck scene in PBS’s “Carrier” documentary and other videos I’ve scene, you have to have the winds so high you couldn’t fly in them…does seem unrealistic to have a 25kt wind and no swell..just choppy waters. For my to get a extremely pitching deck I have the winds set to extremely high

[Raisuli]

I've seen 25kt winds and no swells.  I've seen 25kt winds and 40' seas.  You get spray and some surface chop from wind, but the really big stuff is generated by pressure or, in the case of the Golden Gate ground swell, bottom contours.

Went from Pearl back to Alameda (where the nuclear wessels are*) with some second year midshipmen who thought they were 'real' sailors...at least until we got close to the coast and that ground swell...

*why do the idiots who write Star Trek have the Russian character unable to pronounce "Victor", which is an actual Russian name, because he replaces the "V", which is the third letter in the Cyrillic alphabet with a "W", which doesn't exist in Russian?  Why did the Russian actor allow this to happen?

[Jenson]

try 35 knots wind and 70 turbulence, it's awesome

[Raisuli]

Starboard side looking aft.  The weather decks were secured, but rules only apply to topsiders.  This was as the storm was abating, so things are getting pretty calm now.

Not much wind.  Lots of sea state.  There's 20' of freeboard on this thing.

 

[Nealius]

The "higher wind settings" tag isn't particularly helpful since OP said "without excess winds." There currently is no way to do so in DCS because of the insane wind sheer at 1600ft. Setting 35kts at sea level results in 74kts at 1600ft. 

 

[Dieselmadness]

I don’t understand why sea level and 1600’ can’t be adjusted independently..makes no sense

[Lace]

On 6/29/2023 at 3:03 AM, Dieselmadness said:

I don’t understand why sea level and 1600’ can’t be adjusted independently..makes no sense

It does make sense, if you know how wind works.

I've posted this before, but here we go again...

Wind works like this in real life.  The way DCS does it a bit backwards, but does make sense if you want to define conditions on the ground for airfield ops.  It is realistic that winds 'slack and back' (in the Northern hemisphere) when approaching the surface, so should be about 50% reduced, and backed by 30degrees (veer by 30 in the Southern hemisphere) compared with those at altitude. This is even more noticeable at night where the slacking and backing effect is increased due to colder, denser surface air, however DCS doesn't take this into account*.  The effect is reduced over water where there is less surface friction.  Again, not modelled in DCS's atmosphere*.

Having these independently configurable wouldn't make sense from an atmospheric modelling point of view, as which ever one you choose to define will effect the other.  It is just not realistic** to have the wind speed and direction the same at 1600ft as it is at the surface.

Perhaps ED need to place a note in the manual explaining this to prevent this confusion.

* AFAIK

** 99% of the time.  As always there are some unusual cases where this might not be true.

[Northstar98]

1 hour ago, Lace said:

It does make sense, if you know how wind works.

I've posted this before, but here we go again...

Wind works like this in real life.  The way DCS does it a bit backwards, but does make sense if you want to define conditions on the ground for airfield ops.  It is realistic that winds 'slack and back' (in the Northern hemisphere) when approaching the surface, so should be about 50% reduced, and backed by 30degrees (veer by 30 in the Southern hemisphere) compared with those at altitude. This is even more noticeable at night where the slacking and backing effect is increased due to colder, denser surface air, however DCS doesn't take this into account*.  The effect is reduced over water where there is less surface friction.  Again, not modelled in DCS's atmosphere*.

Having these independently configurable wouldn't make sense from an atmospheric modelling point of view, as which ever one you choose to define will effect the other.  It is just not realistic** to have the wind speed and direction the same at 1600ft as it is at the surface.

Perhaps ED need to place a note in the manual explaining this to prevent this confusion.

* AFAIK

** 99% of the time.  As always there are some unusual cases where this might not be true.

Well, forecasting models operated by various agencies (NOAA, EMCWF, MET office etc) don't show anything like what DCS does, where you're locked into having just over double the speed of the winds at 33 feet, 100% of the time in absolutely all circumstances.

Yes, sometimes you see a doubling, but I've also seen a quintupled and sometimes I've seen it be half of the surface speeds (depending on terrain, location etc).

[Lace]

6 minutes ago, Northstar98 said:

Well, forecasting models operated by various agencies (NOAA, EMCWF, MET office etc) don't show anything like what DCS does, where you're locked into having just over double the speed of the winds at 33 feet, 100% of the time in absolutely all circumstances.

Yes, sometimes you see a doubling, but I've also seen a quintupled and sometimes I've seen it be half of the surface speeds (depending on terrain, location etc).

I qualified my statement that there may be exceptional conditions.  However a 50% and 30degree rule is good enough for this EASA ATPL study guide, and correlates with what I was taught while learning to fly.

WINDS – EASA ATPL Exam Guide (wordpress.com)

 

[Northstar98]

On 12/19/2023 at 4:00 PM, Lace said:

I qualified my statement that there may be exceptional conditions.  However a 50% and 30degree rule is good enough for this EASA ATPL study guide, and correlates with what I was taught while learning to fly.

WINDS – EASA ATPL Exam Guide (wordpress.com)

Looking at the guide, it has surface winds be 70% of the 2000 ft winds over sea (or put another way, the 2000 ft wind speed should be ~1.43× the surface speed, right now DCS is locked to ~2.125×).

You did mention this above, but as this thread is primarily concerned with winds over sea, it doesn't make sense to have the 1600 ft setting locked to just over double the 33 ft setting.

As for backing and veering, that isn't possible in DCS either as the setting is locked to be the exact same direction.

Given that some locations in DCS are indeed areas where (at least from those forecasting models) there are exceptions, I'm personally much more on the side of having the setting be able to be set by the mission editor (as with other wind layers).

Edited March 16 by Northstar98
actually finishing a sentence

[Lace]

Oh, there are so many things which could be 'better' in DCS, but this particular one comes up time and time again by people who don't realise that it is not a mistake, but intentional*, and based on reality.

Proper wind and water modelling, along with swells, chop etc. would be great.  Turbulence downwind of mountains, rotor effect from buildings, trees etc.  The list goes on.

* (either that, or it is a very coincidental mistake)

[oldcrusty]

I saw the thread title... how timely.  Just made my glorious return to carrier aviation on YT

90 kts down the angle. Let's see what a fixed, linear bump through 1600ft would be, hehe.  Well, if that's the only way to create a cool pitching deck so be it

https://youtu.be/JaUz6SHokBw?si=-hN3D_kH_cH5yJZq

 

[bkthunder]

We need a sea state slider, independent of wind (or much more loosely dependent). That's all. 

[Northstar98]

On 12/19/2023 at 4:43 PM, Lace said:

Oh, there are so many things which could be 'better' in DCS, but this particular one comes up time and time again by people who don't realise that it is not a mistake, but intentional*, and based on reality.

Not over water it's not (which is what this thread is primarily concerned with) - and that's from the link you provided.

Of course the real solution is:

On 12/19/2023 at 4:43 PM, Lace said:

Proper wind and water modelling, along with swells, chop etc. would be great.  Turbulence downwind of mountains, rotor effect from buildings, trees etc.  The list goes on.

And there I'm definitely with you.

But I'm going to maintain that decoupling the 33 ft and 1600 ft winds would definitely be a good stop-gap for the time being, given just how long the new weather system is taking (and we still don't know what it'll even entail) - having them be locked together with one just over 2× over open ocean isn't realistic.

[bkthunder]

Maybe after the next EA modules that have recently been announced, they will focus on the weather system (and the ATC, and the AI, and finishing the older EA modules etc..)

[norman99]

On 12/29/2023 at 12:34 AM, Northstar98 said:

But I'm going to maintain that decoupling the 33 ft and 1600 ft winds would definitely be a good stop-gap for the time being, given just how long the new weather system is taking (and we still don't know what it'll even entail) - having them be locked together with one just over 2× over open ocean isn't realistic.

I couldn't agree more!

Edited January 23 by norman99

[Elphaba]

At the risk of self promotion:

 

[Nealius]

^^^^

This. I use this in conjunction with a real weather injector, sometimes getting 17kt winds that cause a decent amount of deck pitching. Not as sporty as the Forrestal but still enough to cause some missed wired.

[Wrcknbckr]

I guess the wind profile in DCS is based on the Atmospheric Boundary Layer theory. It's a relatively simple formulation (see for instance Atmospheric Boundary Layer | How to Set up an ABL | SimScale ) and based on physics, not on what people think it should be. It's an engineering method that is commonly used for the design and performance analyses of wind turbines (There's a reason that current wind turbines are getting taller, simply to 'catch' the higher wind speeds)

Since DCS is not a weather simulator this simple model (physics based) is (probably) used to define wind speed layers at the lower altitudes.  In the formulation one of the parameters defines the viscous effects of the surface; being flat (sea/lake) or urban. This parameter defines the form of the profile. Based on numbers presented by posters I'd say that the parameter chosen by ED matches an airfield (somewhere between a crop field and an area of low buildings). For a set surface wind, the wind speed at 1600ft would be lower at sea compared to land (due to less obstruction at surface level) but then this parameter should be dependent on the location (and infrastructure) and apparently that is not implemented (ED?).

I do not understand why flying with a wind speed gradient should pose problems. An aircraft is not interested in wind. It only cares about airspeed. 

Edited February 26 by Wrcknbckr

[Nealius]

6 hours ago, Wrcknbckr said:

I do not understand why flying with a wind speed gradient should pose problems

Because DCS maps have elevation.

6 hours ago, Wrcknbckr said:

An aircraft is not interested in wind.

Crosswind limits, weapons employment. 

Let's say the Med is a balmy 12kts, perfect for carrier ops. Well now everything on the east side of the Syria map is going to have 24kt winds because it's around 2,000+ ft in elevation. 

[SMH]

Another big issue, you can't set ground turbulence in the NTTR map because almost everything is above 1600 feet ASL. 

Edited February 27 by SMH

[Wrcknbckr]

6 hours ago, Nealius said:

Because DCS maps have elevation.

Crosswind limits, weapons employment. 

Let's say the Med is a balmy 12kts, perfect for carrier ops. Well now everything on the east side of the Syria map is going to have 24kt winds because it's around 2,000+ ft in elevation. 

True that, I was going along the posters line of operating at sea. Elevation is an issue. I can imagine a local wind speed offset that is related to elevation which may be practical, simple to implement and somewhat more representative.

Edited February 27 by Wrcknbckr

[Northstar98]

On 2/27/2024 at 8:58 AM, Wrcknbckr said:

True that, I was going along the posters line of operating at sea. Elevation is an issue. I can imagine a local wind speed offset that is related to elevation which may be practical, simple to implement and somewhat more representative.

The far easier thing to do in the mean time would be to just decouple the wind speeds, because having the 1600 ft winds being locked to double the surface winds in the exact same direction in every single circumstance with no exceptions whatsoever and then have that apply across the entire map is just not realistic.

In the link you provided, there's a logarithmic function for wind speed with respect to height. In that function there's a parameter, z0, for the aerodynamic roughness length. If you were to take the values in DCS and solve the equation for z0, you'd get the exact same result every single time, regardless of whether you were in open sea or in a built up area. When I've calculated the Hellmann exponent (solving for a in this equation), I get a value of approximately 0.2.

The simple fact is, setting up different gradients, which can also be found in the link you provided, simply is impossible in DCS given how the wind speeds are locked together.

As for operation at sea, the problem we have in DCS is if we want realistic wind speeds over land (i.e. what the current system seems to be trying to achieve, albeit with no backing or veering possible) it makes it pretty inaccurate at sea and vice versa. Even just sticking to operation at sea, if I were to set an appropriate surface speed, aircraft in the case 1 stack now have to contend with crosswinds at positions 2 and 4 that are significantly stronger than what they should be. This isn't just my opinion either as this corroborated by the links that both you and Lace have provided.

At the moment, if you were to use a forecasting model (Windy provides a few, though some are only available in certain locations), which are also based in physics, you'd find it impossible to replicate what's being predicted in DCS, at least in certain locations (though in my experience it's more common than not). When you factor in the fact that we have airports at different elevations, the problem is made quite a bit worse.

For an example, at 1000Z today, the ECMWF model, as provided by Windy at RAF Akrotiri (75 ft MSL) is forecasting surface winds that are 11 knots from the west. The METAR report for Akrotiri at 0950Z (found here) was reporting 13 knots from the south-west (so actual surface wind speed is ~1.2× what the ECMWF is forecasting). At 2000 ft (closest I can get to 1600 ft on Windy) the ECMWF is forecasting 14 knots from the west. If I were to set 13 knots surface winds in DCS, I would be stuck with 27 knots at 1600 ft - nearly double.

At Damascus International Airport (2020 ft MSL), the ECMWF is forecasting surface winds of 6 knots from the south west. The METAR report for the airport at 1000Z was showing 10 knots from the south-west. While the ECMWF is certainly lowballing the speeds (this time actual winds is 1.67× what's forecasted), in DCS, with the 13 knot surface speed for Akrotiri, the speed at Damascus becomes nearly triple what it should be. If I try to instead set 10 knots at 2000 ft so I've got accurate speeds at Damascus, the wind speed at Akrotiri is now a third of what it should be and now all my ships have to travel faster (twice as fast in this case) in order to get an optimum wind over deck. Now that wouldn't be too much of a hassle in and of itself (though only because we lack auxiliaries which might not be able to keep up), but the ships are now travelling double the distance in the same amount of time, which is problematic for the more confined waters on the map and makes it much more of a pain to have realistic cycle times for launching and recovering aircraft.

Whichever way I slice it, I'm left in a muddle; I can either choose to have one area be accurate, at the complete expense of accuracy in others, which may or may not involve having the winds at 1600 ft be overexaggerated, sometimes to a significant degree, or I can forsake accuracy entirely, which will probably involve setting a low surface wind such that the winds at 1600 ft are less extreme. All this because the speeds and directions are locked together and all while contending with the implications it has on carrier operations (affecting the distance travelled because of the speeds required to get optimum wind speed over deck and for the required launching and recovery times, as well as crosswinds in the case 1 marshal stack).

If they weren't locked together I would (at least, in this case) easily be able to set up a compromise, allowing me to have much more accurate speeds in both locations while having winds at 1600 ft that are more in line with the forecasting model used and only be a few knots off here and there instead of 10-20 knots off I am with the current system.

And given that the locking only makes sense for certain areas, I see very little reason for it to stay the way it is.

Obviously though, a higher fidelity weather model, particularly one where it's possible to have more localised weather (such as what's possible in the weather commander program for that other F-16 orientated simulator, which would frankly be perfect for our needs) is sorely needed (especially for the Earth map in development) and is the better solution. However, we have no timeframe for either of these things. We don't even know what the new weather system will even consist or what the plans are in this area, or even if there are any at all. So far we've got new clouds, then the clouds were made to move with the wind and we got things like rainbows, glories and ice halos. Past that, all we know is that there's a new fog system in the works, new cloud types in the works (namely cumulonimbus clouds) and LOS blocking for clouds.

Edited March 24 by Northstar98
Grammar