>Friction and waves. The wind approaching you is subject to the effects
>of the water it is coming over. That means if there are waves ( always
>some) it will be disturbed so to speak by the waves. This causes
>little eddies like watching water go over and around rocks (in fact
>wind responds very similarly to water when it meets obstacles). As
>the gust comes it adjusts its pattern to the water (this is actually
>always changing but the first thrust has more to overcome) As the
>waves build and go faster the wind will adjust to that, too. Since the
>wind is a primary factor in the waves eventually they will find an
>equilibrium of sorts.
>Watch a stream sometime and then think of the wind coming over land
>and around cliff faces and such. Evey wonder why it swirls in some
I think Nick hit the nail on the head: waves on the surface of water
are highly dispersive, i.e. velocity of wave propagation is not
constant, larger waves travel faster. When a gust hits and starts to
set up waves, these will be (initially) small so they travel slowly.
If the gust would persist (we wouldn't call it a gust then), then the
larger waves would correspond more to the windspeed.
Dr.Peter I Somlo FIEEE | M1: "Every coin has 3 sides - at least"
Microwave Consultant | M2: "The wind ain't gonna blow from where it
tel/fax: 61-2-9451-2478| ought'a, it'l blow from where it can"