Fog can occur during a warm front.
A weather front can be a cold front, a warm front or an occlusion.
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"A warm front brings light to moderate continuous rain and fog" this is from What weather does a warm front bring? What weather does a cold front bring? - Yahoo! Answers
Warm.
it when a cold front and a warm front meet
Warm air, which brings warm temperatures.
statinary
a warm front
Warm front
a warm front
cold
Warmer