— CampusWeatherService (@PSUWeather) December 10, 2015
The weather pattern across the nation has been stagnant since the weekend, with storms on the West Coast, but clear and warm weather in the east. This pattern was the perfect set up for radiation fog. Other types of fog are advection fog and valley fog.
Radiation fog forms overnight as the heat from the day is transferred or radiates from the ground to the air. Water droplets form as the rising air cools to its dewpoint. The longer nights during winter months and this week’s clear skies allowed for a longer period of cooling at night, which is why we saw a large area of dense fog.
Advection fog forms when warm, moist air moves over a cool surface. As the warm air mass makes contact with the cooler air, water vapor condenses to create fog. This type of fog is common along the Pacific Coast. Valley fog forms in the valleys of mountains when dense air is trapped from escaping.
A shake up to the forecast is expected this weekend with a front rolling through the Plains Saturday to the East Coast next week. Until then, the forecast for morning fog continues.
For WeatherNation: Meteorologist Monica Cryan
(Headline Image: Victor Hiltz)