Stuart Brooks wrote:

OK, I am assuming that the observations came from METAR reports from the
North Sea Rigs. Oseberg is a platform, a picture of which can be seen linked
to from Jon's reply in this thread. Gullfaks/Gullfax is also a platform. The
key thing about the METARS is that they are taken from the Helicopter
Landing Deck and are actual winds, not reduced to sea level. The deck
heights can be over 100m above sea level, in contrast to the 10m quoted on
such websites as Wunderground. The sheer bulk and height of these enormous
structures can also accelerate the free air winds at that height.

Very useful - thanks for this. The 100m vs 10m measuring height is
going to have a significant impact even before considering the effect
that the structure is having on the wind field around it. Further
dangers of trying to interpret winds off the internet !!

Cheers
Richard