The above graph shows the winds at the jetstream level (250 hpa) above the El Sauce observatory. High wind speeds (of 60 kt or more) will likely bring average to poor seeing. Speeds of over 100kts will bring poor seeing conditions. Low wind speeds will likely bring the best seeing for planetary imaging.
You should always look at the jet stream forecast before booking your Live Session of planetary imaging, and make sure that the wind forecasts are well below 60 kt.