On Wednesday, 19 June 2019 00:34:40 UTC+3, Mike the Strike wrote:
On Tuesday, June 18, 2019 at 7:43:16 AM UTC-7, krasw wrote:
Simple table that tells you how much to increase MC at certain headwind component would be enough to solve this issue.

Unfortunately not.

The problem of optimum MacCready speed in wind relates to both wind shear and the relative horizontal velocity of the thermals. With a uniform atmosphere in which the wind speed is constant with height and in which thermals move at the same speed as the wind, standard MacCready theory applies. In these ideal conditions, there is no advantage in changing speed upwind or downwind.

In the case where thermals move more slowly than the wind (the more general case) or where they don't move at all (wave), the optimal speed will generally be faster upwind and slower downwind. This is what many experienced cross-country pilots have intuitively figured out in the real world.

Mathematical analyses of these have been done by several folks, including John Cochrane and Branko Stojkovic. Long enough ago to be forgotten.

The solution of speed to fly with wind is not easy, since the effects of wind shear and thermal speed are variable and may not be known well enough for a satisfactory general mathematical solution.

Mike

I'm aware of all this. You either fly towards fixed spot on the ground (final glide), or towards cloud or thermal. We can approximate that your home airfield does not move with the wind at all and thermal moves at wind speed (which is does not, of course, but this is approximation). Final glide to fixed spot you would increase mc to take wind into account, glide to next thermal you would (mostly) not as it will be blown towards you at wind speed. This simple idea turned into mc value to increase or subtract would get you 99% of the theoretically optimum glide speed. We do not have to worry about exact figure as we can maintain certain airspeed at maybe 5% accuracy. Accuracy above that has only academic interest.