Yet another no-go which I had to try out. A tarp above treeline with strong winds and rain and mosquitoes. I basically stick to Ryan Jordans guide for tarping in extreme conditions and Collin Ibbotsons talk about tarps. I used a homemade tarp with 4 guy-outs on each side and one on each ridge-end. As stakes I used:
2 Y stakes for the ridge-line
4 V stakes for the corners
5g Titanium needles for the rest of the guy-outs.
It worked fine, I could have left the V stakes at home for the corners as the titanium stakes worked well with the Scandinavian stone ground. I always put stones on the stakes to avoid that they are removed by a gust of wind. In the end I stayed dry and had no condensation issues. Not a single stake got loose even with strong wind gusts. As the wind direction changed to the complete opposite, bringing rain and wind into the front opening, I was happy that my bivy protected me from the raindrops that made it over the security boundary( I sleep 30-50cm away from the opening).
For the mosquitoes I used a homemade bivy bag made of pertex quantum and nanoseeum. It was perfect for quilt sleeping(wind) and keeping the bugs away. I could even change my clothes in it. It was interesting to see that the bugs didn’t like the quantum, I could offer them my whole naked leg and they never came to the idea to puncture it through the quantum.
Things I would change on my tarp:
Add a beak at the front, because wind and rain direction do change :)
use 5 guy-out point on the sides
use 3 guy-out points on the front opening(or beak)
Things I would change on my bivy:
use a silnylon floor and back-head area again, as for wind changes and non-waterproof ground sheets.