Why do cirrus clouds arrive before other clouds as a warm front approaches?

Question

Why do cirrus clouds arrive before other clouds as a warm front approaches?

Answer 1

Because winds at the top of the thunderstorm cloud are stronger causing the cirrus to blow off.  See the source link for a graphic.

Answer 2

If the warmer air flows actively upwards over the cold air-mass below,then it is called warm front.The slope of the warm front is gradual .Due to this steady upglide motion,a broad pre-frontal system of stratiform clouds exist ahead of the front with cirrus cloud arriving before other clouds.This is because the front portion of the warm front(which is ascending over the cold mass) will be at the maximum height initially and at this height, only high clouds like cirrus can form.