How do airlines decide which flights to cancel and which flights to fly to / from the airport affected by miserable weather on the same day and hour? Is it pilots training/certification, crafts hardware, or something else?
Eg on 2/17 around 2pm in DTW winter storm with rain started changing to sleet to freezing rain to heavy snow, somewhat c.30% (Delta) to c. 45% (Spirit) flights were cancelled, but still some crafts were landing and taking off.