See this area during a simulated summer evening thunderstorm.
Clarifying Fog
A summer evening shower or thunderstorm often leaves the ground soaked just as the sun sets. Even if the rain stops overnight, the high humidity level created by the rainfall won't allow the moisture to evaporate. Fog forms, especially when there are light winds. As the air warms up the next morning this rain-enhanced fog usually burns off by about midday.
What is Fog?
A visible aggregate of minute water particle (droplets) which are based at the Earth's surface and reduces horizontal visibility to less than 5/8 statue mile, and unlike drizzle (freezing rain), it does not fall to the ground. The rapidity with which fog can form makes it especially hazardous. It forms by any atmospheric process that does one of the following:
- Cools the air to its dew point
- Raises the dew point to the air temperature.
Names given to fog types identify their methods of formation. The principle types are radiational fog , ice fog , advection fog , upslope fog , rain induced fog , and steam fog . These types of fog are called "dense" when the surface visibility is equal to or less than 1/4 miles. A Dense Fog Advisory will be issued when the dense fog becomes widespread.
References: Princeton University, The National Weather Service and USA Today.
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