Satellite images show huge fog formation haunting central California

"The low cloud formation, known as tule fog, first formed over central California in November and persisted into early December. The Central Valley typically sees this type of fog during the colder months of the year, when the air near the ground is cold and moist, and the winds are calmer, allowing moisture in the air to transform into a thick layer of fog."

"As the cold blanket of fog forms, it becomes trapped in the bowl-like shape of the Central Valley. The warmer temperatures of the air above keep the fog stuck in the valley like a lid over a pot, also known as temperature inversion. As seen in Nasa's imagery, the tule fog remains steady over the Central Valley, moving through the Carquinez Strait in December, toward the San Francisco Bay."

"The lingering tule fog has contributed to the chillier conditions locals report feeling in central California and the Bay Area. The Central Valley has experienced an average low temperature of 37F and average high of 63F so far this month, with the Bay Area at 43F and 65F, respectively. Drew Tuma, ABC 7 News meteorologist, writes that as the fog tries to move out of the valley,"

Tule fog formed over central California in November and persisted into early December, covering the Central Valley. Cold, moist air near the ground and calmer winds allowed moisture to condense into a thick fog layer. The valley's bowl-like shape and warmer air above created a temperature inversion that trapped the fog. NASA satellite imagery showed the fog remaining steady and moving through the Carquinez Strait toward the San Francisco Bay, with imagery of fog stretching about 400 miles. The fog followed a major late-October storm that NOAA linked to a severe thunderstorm outbreak. The National Weather Service issued dense fog advisories as visibility fell below 1/4 mile on some mountain roads. Reported temperatures have been cooler, with Central Valley averages near 37F lows and 63F highs, and the Bay Area around 43F lows and 65F highs.

Read at www.theguardian.com