Question

What is the first sign of an approaching warm front?

Answer 1

Hint: When two air masses meet together, the boundary between the two is referred to as the weather front. A warm front signs the leading edge of moving warm air.

Complete answer:
Fronts are the primary reason for stormy weather. Down a warm front, a warm air mass glides over a cold air mass. When warm, less dense air passes over the colder and relatively denser air, the atmosphere becomes relatively stable. The first sign of an approaching warm front is the appearance of high, thin, wispy cirrus clouds.

High cirrus clouds symbolise the change from one air mass to the other. With time, cirrus clouds become thicker and transform into cirrostratus clouds. As the front advances towards, altocumulus and altostratus clouds appear and the sky becomes gray. Since it is winter, snowflakes can be seen falling. Snowfall increases as the clouds become thicker and changes into nimbostratus clouds.

As the front gets more and more closer, the cold air mass is just above us but the warm air mass is not too far above that. Therefore, the weather becomes worse. As the warm air mass approaches, temperatures rise and snow changes to sleet and freezing rain. Warm and cold air merges at the front, which leads to the formation of stratus clouds and fog.

Thus the first sign of an approaching warm front is the appearance of high, thin, wispy cirrus clouds.

Note: There are 4 types of fronts: Stationary, Cold , Warm and Occluded. Three of these are progressive and one is stationary. With cold fronts and warm fronts, the air mass at the foremost edge of the front offers the front its name. In other words, a cold front is right at the leading edge of moving cold air and a warm front signs the leading edge of moving warm air.