jake_the_lab_weather.js

$(document).ready(function() {  
  $.YQL = function(query, callback) {
      $.getJSON('http://query.yahooapis.com/v1/public/yql?callback=?', { q: query, format: 'json' }, callback);
  };

  $.YQL("select * from rss where url='http://weather.yahooapis.com/forecastrss?p=UKXX0133'", function (data) {
     var w = data.query.results.item,
         klass = w.condition.text,
         encodedclass = klass.replace(/\s+/g, '-').toLowerCase();
   
     $('body').addClass(encodedclass);
  });
  
  var weather = $("#weather")
        .show()
        .delegate('li', 'click', function (e) {
          document.body.className = this.className;
          e.preventDefault();
        }),
    
  menuYloc = weather.position().top;
    
  $(window).scroll(function () {
    weather.animate({top: menuYloc + $(document).scrollTop()}, {duration:500, queue: false});
  });
});