Why doesn't scrollTop fire on fast scroll?

Question

JavaScript

If I scroll up smoothly, the red block gets smaller, i.e. works fine, but if it's fast, then for some reason it skips.
Help me to understand?
codepen.io/anon/pen/MKvZad

Answer 1

$(window).scroll(function () {
  var s = $(window).scrollTop();
  if (s > 10) {
    $('.header__navbar').stop( true, true ).animate({
      height: "180px"
    },{duration: 100, queue: false});

  } else if (s <= 10) {
    $('.header__navbar').stop( true, true ).animate({
      height: '130px'
    },{duration: 10, queue: false});
  }
});