The correct answer is C) Southerly winds with steady rain; fog or overcast. With a warm front stationary over the Kentucky-Missouri-Tennessee region, you would expect southerly winds to be bringing warm, moist air into the area. This typically leads to increased cloud cover, steady rainfall, and potentially fog or low overcast conditions. The warm front acts as a boundary between the cooler air to the north and the warmer, more humid air to the south, resulting in the weather conditions described in option C. The other options are incorrect because a) a strong northwest wind with thundershowers is more indicative of a cold front, not a warm front, b) a "blue norther" is a rapid drop in temperature associated with a strong cold front, not a warm front, and d) light northeasterly winds with clear skies would not be expected with a warm front in the region.