Try
$(this).animate({opacity: 'hide', height: 'hide'}, 'slow');
Note: in case you need it the animation to make it appear will be:
$('#myDiv').animate({opacity: 'show', height: 'show'}, 'slow');
If you want one effect start after the other ends try using a callback:
$('#element').fadeOut('slow',function(){
$(this).slideUp('fast');
});
But don't think that look nice .