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What visual flight conditions can be expected after a cold front passes?

  • A

    Scattered cloud layers, visbility more than 5 km, formation of shallow cumulus clouds.

  • B

    Medium visibility with lowering cloud bases, onset of prolonged precipitation.

  • C

    Poor visibility, formation of overcast or ground-covering stratus clouds, snow.

  • D

    Good visibility, formation of cumulus clouds with showers of rain or snow.

Refer to figure. 
The first sign of the approaching cold front is a line of cumulonimbus clouds, accompanied by showers and gusty winds. After the front passes, the cloud base rises, the clouds thin out, and precipitation diminishes. Visibility improves outside of the showers. Behind the front, the southward-moving polar maritime air is warmed from below, creating instability. This results in scattered, isolated cumulus clouds forming behind the front.

Changes on the Passage of a Warm Front

Temperature and dew pointVisibilitySurface PressureCloud and PrecipitationWind
Temperature increases as cold sector air is replaced by warm sector air and dew point increases.Visibility steadily decreases as the front approaches, then at the front itself except frontal fog.Falls as area of low-pressure approaches then steadies in the warm sector.Cloud base lowers and cloud thickens with steadily increasing precipitation.Backs initially then veers at the front with a steady increase in speed.

Changes on the Passage of a Cold Front

Temperature and dew pointVisibilitySurface PressureCloud and PrecipitationWind
Temperature and dew point falls as warm sector air is replaced by cold sector air.Just ahead of the cold front, and as it passes, visibility will be poor, but after the cold front, visibility will improve except within the showers behind.Falls as front approaches, then rises as front passes.Embedded cumulonimbus just ahead of the front then after the front passes, cloud base rises and the clouds thin. Isolated cumulus behind the front.Backs just before the front, then veers sharply at the front and increases in speed. After the front has passed the wind will decrease and back.

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