Challenging, but do-able...

Dear J,

I fully expect a deluge of "but Physics doesn't scale" responses,
but I would suggest that:
1 - it's challenging (no doubt, be prepared to "trailbaze" where few have been before you, it's going to be lonely)

2 - but do-able
(Disney Imagineers and similar have been achieveing "scale wind effects" for literally decades)

3 - assuming you focus on the end-visual-effect you're seeking to achieve
(we don't "see wind", but we see the effects of things it acts-upon... important headspace distinction...
...also, and I've said this a bit recently, the key to achieving such "envelope-pushing" modelling missions is to start with a clear idea of the end-result you want to achieve, it's all-too-easy to burn much time/effort/brain-cycles chasing nothing-in-particular... we do serious-levels of prototype research before commencing a visual Scale model, there is no darn difference between that and building a sonic or animation Scale model...)

4 - and thus recognize that any and all kitbashing of any/every/all avaiilable12"/1' physical forces required to achieve the desired "end result visual" is Fair Game
(See YT "Laurie McLean" or "ScoopMMR")

To this end, I would suggest you check-out and read-up on:

- "Laminar flow" wind/water systems
(IE how to get "targetted air-flow", without the noise or problems of turbulence or cavitation)

- Control of Volume, Pressure, Area-of-application, Direction, Drafting, and Dispersion
(each can be controlled somewhat individually, which gives the creative-control to adapt to all manner of desired scale applications. There are many parallels to Layout Lighting, Sound, and Smoke-gen effects.)

- Consider that you may not have to use actual wind to create "the impression of wind effects"
One of the more-engaging examples I've seen is a weathervane, apparently rotating smoothly+randomly in "the wind"... the actual mech was a slow-rotation cam'd offset magnet, interacting with a magnet mounted offset-on the vertical shaft of the weathervane... That it was a magnetic-flux coupling rather than a fixed-mechanical coupling was instructional and intriguing...

...come to think of it, an early D. Derek Verner MR animation article involved animating an N scale windmill, using an aquarium filter pump to provide low-level vibration, which imparted/induced "lazy wind" rotation into the (otherwise free-spinning but un-powered) windmill model...

I also see a number of low-voltage low-rpm PC fans,
some conduit/ducting and sillicon-caulking,
and some cheap lunchbox/tupperware/junction-box enclosures
(for surge-tanks, mufflers, and flow-pressure adjustment)
in your future...

Best of Luck, looking forward to seeing where the wind takes you...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Mmm ... sounds like it my be

Mmm ... sounds like it my be more complicated then I was thinking. I was using my compressor and fish tank 4 mm piping with little taps to regulate the airflow. But the sound needs a bit work on. But can you image if a train rolls thru a station swishing stuff around. I thought of putting trees with their branches cut off and reglue them back on with flexible silicone so it moves with a slight breeze. And trees have a thin piece of fishing line thru ground that is weighted down under sub roadbed and when the wind backs off the tree pulls back into position.  

For operations you could have you air tank go off on a timer a random times.         

Interactive, random, and tree-movement...

Dear J,

Both "Interactive" and "random" wind-effects are do-able, the event-triggering/sequencing is almost trivial, 
once you have the actual visual effect system/mechanism sorted.
(See early physical-model era "Thomas the Tank Engine" wind/water/steam modelling interactions as examples).

Same for the matching audio SFX, modellers tend to think in terms (only) of "sequencing and triggering" because that's the easy/sexy end, (cue coding, JMRI, Arduinos, etc etc),
but without an actual sound/output-device with which to achieve the desired tangible result,
all the "sequncing smarts" is nowt but silent/stationary code...
(or, arguably worse, a quite potent "control rig",
but a "visible/audible end result" which is soooo crude/toy-like,
as to make the aleged attempt at "scale" effect laughable...)

As far as "swaying trees" goes, again, the prototype is your guide, friend, and sanity-check. It takes a fair bit of wind to bend/sway a 6" dia branch, much more likely is "fluttering leaves"...
...and a "super tree" armature with strategically-applied Heki-flor foliage has enough "leaf detail, connected by minimum-force-to-flex supports" to be reactive to low-velocity PC-fan-forced wind forces...
(weighted-forces often exceed sane "scale wind" effect forces,
I suspect you'll find yourself playing more-frequently with various "leaf springs" formed with 0.0xx phosphor-bronze wire or similar...)

Happy Modelling,
Aim to Improve,
Prof Klyzlr

You can visually do it without the wind

Depending on where you live, and how much wind is prevalent, you have certain effects on the landscape.

See prevailing winds.

On the plains, where fairly consistent winds blow, trees often have a slight lean as the wind affects tree growth.

Also consider that in areas of prevailing winds, the levels of weathering may be greater on one or two sides of a building, depending on the direction of the prevailing winds, than on the opposing sides.

one word

J,

A few yrs. ago I saw an ad for waving flag for your layout.  Not my cup of Joe.

A fan from a computer would work,  but for some of us,  the word is      ,DUST.

One mans art is another's p fill in the blanks.

Boudreaux,  B.C.E. 

Back to the bridge work in the swamp!

Idea

Some people like to put their trees on small springs, so that when operators accidentally brush against them, they don't snap over.

What if you had a small plate under the layout, and attached all the trees via springs to this plate? Then, add a small vibrating motor or servo to simulate motion.

Trees moving in the wind

Trees moving in the wind sway, they don't "buzz". This is indeed, as the good prof suggested, another case of "physics doesn't scale". What you're missing is the flexibility, mass and pendulum effect of the tree. Accomplishing this without mechanical means isn't going to happen.

Back when the remnants of Hurricane Ike came through Ohio, I saw 60-80 foot oak trees moving in 70MPH+ winds...   even in those rather extreme conditions, they didn't look like that.

Lot of work for small effect

Seems like a lot of work for minimal effect.  I mean when you are watching a train do you really notice the wind....unless it so strong or so cold that you decide its time to get in the car and go home?  Most of the time you feel the breeze but do not see the effects...unless it actually is blowing hard enough.....then everything is getting the effect...trees, grass, flags, trash. If just a couple of things move then it may just look cheesy.

Have fun but...seems like this is more for a carefully planned small diorama than a model railroad.  Maybe a fully rigged and flagged sailing ship?

I've never thought of moving

I've never thought of moving the trees but I've often thought of strobes for an approaching thunderstorm with a fan blowing a gentle wind into the viewers direction. Also don't forget the old John Allen trick of putting a kite on the end of a fine fishing leader or guitar string with the springiness of it holding the kite up in the air. It might be interesting to see how a kite done that way might react to a fan breeze.

Having grown up out on the

Having grown up out on the edge of the cities and spending most weekends at the cottage in the country surrounded by trees and even now living on acerage I have observed trees my whole life.  And the thing is in a slight breeze you see the thin outer branches and the leaves move but it takes a more significant wind to sway trees at least in areas Ranging from Michigan to West Virginia and beyond.  
 

The problem is these effects don’t scale well.  The same way that a prototype car rocks slowly back and forth but a scale car jiggles back and forth.

Somecthings can’t be scale down.

-Doug M 

Yes I think you guys are

Yes I think you guys are right trees dont really move but I think  shimmer in leaves and small items to indicate wind is in the air.  A kite, newspaper, washing on the line, flag etc this I think this is easier than moving a tree and is more prototypical. 

Review

Dear J,

...so, review video of:
- Swans Crossing (unintentional but very effective "tree leaves motion")
- "ScoopMMR" on YT (making almost everything move)
- Red Stag (passive-motion of secondary items such as washing-on-line and kites)

would, I respectfully suggest, be in-order...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

PS Scenic items with rods/pendulums extending down thru the benchwork,
either weighted/passive-movement, and/or weighted+active-magnetic-interference drives,
are entirely fair game...

wind

you could think of ways to give the appearance of wind.  all flags, laundry. loose things that could be wind blown pointing stiffly in the same direction, waves on water and tree branches in the same direction,  collected litter against walls and fences in the same direction? i know it's not animated, but it could help to create the illusion of wind.  

@kebmo  yes I think that is

@kebmo   yes I think that is a good idea  so I'm going to do both build those items you talked about in a fashion but with a smallest amount of puff of air only, so certain light flexible parts will move abit. It will be easier to manage a small spurt of air and to try to make it random. I will place it on my front wireboard with little taps to distribute the air to specific places.  Thanks.

P.s. In the end it's not my layout and I'll do what you want.    ...only if it fits within my story.

Modeling moving water and wind

Thanks Joe  ...I've done some

Thanks Joe  ...I've done some testing and I am improving it abit, but trying to make it subtle is quite difficult.

I have wondered if “cheering”

I have wondered if “cheering” would help.

Some thoughts I have had.towards this.  After the tree is all but finished spray the outside of the tree a bit different color, then when the “leaves” move you will reveal the other original color so you will get a noticeable color shift.

For leaves or water I have wondered if you can use some sort of moving light or changing color or intensity of light .  Because with leaves you usually see a cloro shift (both sides of a leave are usually not the same exact color/texture. And obviously you just see the light reflectin* off the surface of the water in different directions so the water almost shimmers.

Remember we don’t care if the water or leaves actually move we are after an illusion.  My steam engine is not running on coal fired water.

-Doug M

@Jim jTrackin re:Tree Movement

Hi Jim,

The movement caused by a small puff/flow of air will likely not scale well for whole tree movement -- the physics are just not on your side. However, that is no reason at all to stop pursuing wind effects animation. Small air movement will only effect outer small branches, top branches and leaves. Movement of leaves can be spectacular. If you have ever witnessed aspen trees in Colorado subject to the wind? The leaves will flutter and each side is remarkably different -- fantastic scene. I have no idea how to model it. It would require some tiny color/light change effects without moving the trees very much.

Ignoring using moving air which is incredibly problematic, consider something like a poplar tree, modeled with a very flexible trunk, that could be bent by stiff hidden wires. A combination of bending a group in sequence together with synchronized audio could create a good animation on a ridge line or as a field (or road) boundary. The big issue is slowing down the effect to simulate the mass of the tree in motion -- no jerky effects allowed.

Maintain the vision you are after in your mind, and work step by step to get closer to building that view. You will be incredibly lucky to achieve what you are after in only one try.
Have fun! 
Best regards,
Geoff Bunza

Trying to emulate wind in

Trying to emulate wind in your layout you tend want to observe nature. I find myself looking at trees and the movement they make. I don't think I ever appreciated trees and the air effect on them so much before doing this project. 

Here is some of my installation on one part of the layout. Basically, to see is this a thing or not. I found you shouldn't use aquarium fish taps they are not sturdy enough. I use 4mm tubing for garden watering systems and the taps are solid. The nozzle where the air comes out needs to be small I have the tube from the plastic from the 12awg wire (with the wire taken out) works well at the very end (10mm) aim it an important spot that you wish to move. That way you only need a small amount of air. 

Installing hose and tap
       

Air comes down the back of the layout and into 4mm air hose on front on the wireboard.

I will be treating this like a TOMA a bit just doing one section. Come back to it play with it etc. It is structurally in place so it is about thinking appropriate items to be blown.  

So far 2 taps in place but can split them into more underneath the layout. 

The tree leaves (roughly thrown on) and flag (rigid too stiff)  move slightly in video.