https://maweco.work/posts/its-quite-windy

its-windy.js

var Ball = function Ball() {
  this.loc = createVector(width / 2, height / 2);
  this.vel = createVector();
  this.acc = createVector();

  this.col = color(random(55, 200));

  this.sz = random(10, 25);
  this.mass = this.sz * 1.5;
}

Ball.prototype.addForce = function addForce(force) {
  var f = p5.Vector.div(force, this.mass);
  this.acc.add(f);
}

Ball.prototype.move = function move() {
  this.vel.add(this.acc);
  this.vel.limit(1);
  this.loc.add(this.vel);

  this.acc.mult(0);
}

Ball.prototype.keepInView = function keepInView() {
  this.loc.x = constrain(this.loc.x, 0, width);
  this.loc.y = constrain(this.loc.y, 0, height);
}

Ball.prototype.draw = function draw() {
  fill(this.col);
  ellipse(this.loc.x, this.loc.y, this.sz, this.sz);
}

var Arrow = function Arrow(w) {
  this.wind = w;

  var fake = this.wind.copy();
  fake.y *= -1;
  this.loc = p5.Vector.sub(fake, createVector());
  this.loc.normalize()
}

Arrow.prototype.setWind = function setWind(w) {
  this.wind = w.copy();
}

Arrow.prototype.draw = function draw() {
  push();
  translate(width / 2 + this.loc.x, height / 2 + this.loc.y);
  fill(255);
  rotate(atan2(this.loc.x, this.loc.y));
  ellipse(this.loc.x, this.loc.y, 10, 10)
  triangle(
    this.loc.x + 5, this.loc.y + 0,
    this.loc.x - 5, this.loc.y + 0,
    this.loc.x + 0, this.loc.y - 10
  );
  triangle(
    0, -width / 2 + width / 64,
    10, -width / 2 + width / 64,
    5, -width / 2
  );
  pop();

  var fake = this.wind.copy();
  fake.y *= -1;
  fake.normalize();

  var to = p5.Vector.sub(fake, createVector());
  this.loc.lerp(to, 0.02);
}

var Wind = function Wind() {
  this.wind = null;
  this.update(0);  
}

Wind.prototype.update = function update(a) {
  this.wind = p5.Vector.fromAngle(a);
}

Wind.prototype.get = function get() {
  return this.wind;
}

var balls = [];
var wind = null;

function setup() {
  const c = createCanvas(685, 685);
  c.parent("sample");

  balls = new Array(2).fill(0).map(() => new Ball());
  wind = new Wind()
  arrow = new Arrow(wind.get());

  noStroke();
}

function draw() {
    background(25);

    if (frameCount % 100 === 0) {
        var windDir = random(0.0, 1.0) * 2 * Math.PI;
        wind.update(windDir);
        arrow.setWind(wind.get());
    }

    balls.forEach((b) => {
      b.addForce(wind.get());
      b.move();
      b.keepInView();
      b.draw();
    })

    arrow.draw();
}