www.iksurfmag.com/issue62/?page=53A must read article in the latest issue of the International Kitesurf Magazine for those who contemplate kiting in winter fronts/storms, also a great timing as winter kiting conditions aren't so far away.
I would add 2 things that weren't mentioned in this article:
1) Double the wind speed = 4 times the amount of power delivery in your kite so 40 knots is 4 times the power you would normally feel in 20 knots!
2) Frontal winds are much colder than sea breezes and pack a lot more Punch due to air density. so a 20 knots cold winter wind will pull as much as a 25 knots hot summer breeze.
Stay safe,
Christian