Being in close proximity to Mam Tor, Lord’s Seat, Rushup Edge, Treak Cliff and Longcliff, Rowter Farm has a relevance to all these sites.
The landing field at Rowter is the large triangular field to the West of the farm complex. It is bounded on its East side by the driveway from the main road.
It is sometimes used as an “over the back” option when Lord’s Seat is flyable (that’s planned, as opposed to running away if blown back). It can be used from Rushup if you can keep height and push into wind.
It’s also a landing option from Mam Tor, Treak Cliff and Longcliff. If trying to avoid going to the bottom landing field, it may be a better option than Windy Knoll, because…
Windy Knoll is often seen as a benign place, and when landing there from good soaring on Rushup Edge, it most usually is.
Using Windy Knoll as an option for landing from Mam Tor in an Easterly – there is a high chance of rotor behind the spine that bounds the landslip face. This should only be attempted by experienced pilots fully aware of \ briefed on the risks (and how to avoid them) and prevailing conditions.
Using Windy Knoll as an option for landing from Treak Cliff in an Easterly – there is severe rotor behind Treak Cliff – you need plenty of height (site guide suggests the height of Mam Tor) to get over this rotor to reach Windy Knoll.
For all the above sites, the more Northerly component the wind has, the more the risk increases that the whole of Mam Tor and Rushup Edge will generate rotor directly on to Windy Knoll. These conditions are extremely dangerous, and you should not try to land at Windy Knoll – go to Rowter Farm (if height allows) or the bottom instead.
(Note that the Castleton valley may effectively funnel the wind, giving the impression that it is more Easterly than it actually is.)
The attached pictures are of the areas mentioned above – to give a general idea.
Caveat – it’s doubtful anyone really knows exactly how far areas of rotor stretch back from that which generates them, or how high they reach. The pictures are just an aid to understanding the words. It’s a complex area and there are risks – risks that change according to the conditions at any given time. There are far too many variables for simple pictures & words to convey & cover fully.
You, as the pilot in charge, make the decisions regarding your flight plan \ conditions \ risks \ your ability. You should gather as much information as you can, from a range of sources, to enable you to make informed choices.
There are no definitive “this is what to do every time and you’ll always be safe” rules. There can be rotor off that spine. There can be rotor out the back of Treak. Windy Knoll can be very dangerous.