South-westerly

A gentle flow from directions between west and south gives rise to expectations of pleasant flying conditions for Fiesch, provided that it isn’t also associated with föhn. The chart below was associated with plenty of good flights from Fiesch that day, but the south overpressure of nearly 4hPa was borderline.  The airmass arriving from this direction is often warm, which can produce the highest cloudbases of the summer, although it may also bring higher humidity to offset that effect, but at least the thermic activity in that situation is usually excellent.  Stronger south-westerlies can provide assistance for long XCs to the east in the form of a tailwind and opportunities for slope lift, but at the expense of interference with the morning thermals in the Goms (see my third example flight below).In this situation, the Grimseler is suppressed, and progress to the east assisted, but the wind in the main Rhône valley beyond Brig can be funnelled through at 20-30km/hr up to 2400m, presenting an almost impenetrable barrier for paragliders. Forget about triangles in these conditions; the name of the game is free distance, and the classic flight is to Chur, 120km to the east. If you’re really determined, in the right conditions it’s possible to fly to Austria, but remember to pack a toothbrush and bring some euros, because you won’t then make it back to Fiesch under your own steam until the next day.

My first example flight is in light south-westerly conditions, when the wind was gentle enough that I was able to turn around just beyond Flims and fly back to Disentis (with a little assistance from the valley breeze, which blows in the opposite direction):

Flight in light south-westerly conditions (click here for 3D visualisation, here for XContest details)

In my second example, the wind was a little stronger, leading to some fast downwind glides and the use of some dynamic lift off south-westerly faces just before both the Furka and Oberalp passes to assist the crossings:

Flight in light to moderate south-westerly conditions (click here for 3D visualisation, here for XContest details)

My third example is from a day in which the thermic activity was relatively poor, leading to low expectations of a long XC, but the south-westerly flow enabled me to use slope lift to jump from one windward face to the next in some sections, and make distance by simply circling in weak lift and drifting along at 20 km/hr, thereby clocking up over 100km, albeit at much lower level than usual:

Low level flight in moderate south-westerly conditions and weak thermals (click here for 3D visualisation, here for XContest details)

This 3D visualisation shows where slope lift helped me cross the Oberalp Pass in south-westerly conditions.

Being able to access live wind information in flight is particularly useful in south-westerly conditions.  For safety, it’s a good idea to keep an eye on weather stations relevant to föhn, as this possibility should always be in the back of your mind on such days.  A brisk wind from this direction can disrupt the usual thermals at Bellwald, so you may do better to either stay on the windward slope there or glide on, rather than struggle near terrain in rough broken lift, losing height all the while.  Also, it’s very helpful as you enter the Urserntal to know what the wind in Andermatt is doing.  If it’s strong from the north, you should prioritise staying high, out of the headwind of the valley breeze which kills thermic activity lower down, and maximise height before crossing the village, whereas a vigorous gusty flow from the south-west may indicate föhn at ground level, but you can then speed on in the expectation of assistance from dynamic lift on the south-facing slopes before Oberalppass.