Current Fog Conditions

Fog FAQs Cities Fog Cities Visibility Seasonal Foggy Days Satellite Image

 

1-What is FOG?

Under light wind(stable) and humid conditions, if the air near the ground cools down sufficiently, water vapour in the air may condense into tiny water droplets. These droplets reduce the visibility near ground level. The phenomenon is called fog. In Pakistan fog is common in wintertime between December to February.

2-What is the diffrence between fog and mist?

According to the World Meteorological Organization, fog is said to have occurred when the visibility is reduced to less than 1 km by water droplets suspended in the air. For mist, there is no uniform definition at present. Different places in the world use slightly different definitions. In Pakistan, mist is said to have formed when the visibility falls between 1 to 5 km and Relative humidity is less then 90% .

3- What causes the fog commonly seen in wintertime?

In wintertime, Punjab, K-P and upper Sindh areas are affected by Fog. As cold air from the north recedes and day temperatures falls sufficiently, warm and humid air comes in from the sea. During this time, the warm and humid air may be cooled sufficiently by the underlying cold surface. This results in condensation of water vapour into droplets and hence formation of fog

4- What is the relationship between atmospheric stability and fog?

When the air near the ground is colder than the air aloft, the denser air near the ground will not rise and will remain in its original position. The atmosphere is said to be stable. Stable atmosphere is favorable for fog formation. The atmosphere is usually more stable in winter, and is relatively unstable in summer. 
In the same way, under stable and dry conditions, dust particles suspended in the air are not easily dispersed, resulting in haze.

5-What are the effects of fog on our daily life?

Fog has a great effect on traffic. In Pakistan, dense fog has led to Road accidents and aircraft delays, resulting in injuries and economic losses because of dense fog. Fog can also play tricks on the other senses, changing the way that sound and light move, making it difficult to orient oneself.


Copyright © Pakistan Meteorological Department All rights reserved design by Nauman Ali Qureshi