Weak Thermals In Strong Wind

      When you’re obliged to regain ground lost drifting in strong wind and weak lift, a slow climb can be counterproductive.   Consider the following very plausible scenario in a 40/1 sailplane.   You're low enough to think about landing when you find a one-knot thermal drifting in a twenty-knot wind.   By the time you gain 200 feet of altitude, your thermal will have drifted 4,000 feet downwind from the landing area.   This distance divided by the 200-foot climb nets a 20/1 ratio.   When your thermal is torn apart by wind, simply gliding back to where you started will require increasing airspeed by half the estimated wind to maximize the glide (meaning a greater sink rate through the air).   Meanwhile, your actual ground speed is reduced by the whole amount of the wind speed - so your optimum achieved glide slope will now be not much better than 20/1.   If you find sink when leaving the thermal or prior to reaching another one, that added disadvantage would demand still higher airspeed and a further increase in sink rate.   Conclusion:   a 20/1 glide might be better than you can do!    In a wind of 20 knots or more, an achieved climb rate of less than 200 feet-per-minute may cause more problems than it solves.