Which weather condition, specifically within a 10 nautical mile radius, is cited as an absolute no-go for a launch?

Lightning.

Weather conditions are paramount controllers of launch readiness, and certain phenomena trigger immediate scrubs regardless of other favorable factors. While issues like upper-level winds, cloud ceilings (which reduce visual impact), and even moderate surface rain might be manageable or worked around, the presence of electrical activity near the launch site is an immediate disqualifier. Specifically, the presence of lightning within a defined perimeter around the launch pad, often cited as 10 nautical miles, constitutes an absolute requirement for scrubbing the attempt until the area clears of electrical danger, due to the risk posed to the vehicle's sensitive electronics.