LAHTI, Finland — Moments before the women’s 10-kilometer classic individual start at the 2017 Nordic World Championships on Tuesday, temperatures read 35 degrees Fahrenheit and humidity hovered around 97 percent — the air nearly saturated. Earlier in the day, a near-ground fog lapped the tops of the three iconic ski jumps looming above the ski stadium. In contrast to earlier classic events at these championships — a 15 k skiathlon, and classic team sprint — the...