Analysis of Meteorological Conditions for a Sea Fog Process in 2016

The visibility characteristics and meteorological conditions of a sea fog process on 27th February, 2016 are analyzed and the heavy fog process is simulated by the Weather Research and Forecasting (WRF) model in this paper. The forecast results show that the visibility in Qingdao coastal area is light fog on the night of the 26th. In the WRF simulation, it can be observed from the sea-level pressure that the wind direction of Qingdao and the coastal area turned southerly with the eastward movement of the low pressure system on surface from 1200 UTC to 1800 UTC on the 26th. A large amount of water vapor brought by easterly and southerly wind provides sufficient water vapor conditions for the formation and development of the sea fog. At 975 hPa, there is a strong warm tongue over Shandong Peninsula at 0600 UTC on the 26th, while the offshore is affected by the cold tongue, where the horizontal temperature gradient is large and there is a strong baroclinicity. At 850 hPa, there is a weak warm ridge over Qingdao at 1200 UTC on the 26th, which means that it is an inversion layer, which is conducive to the maintenance of fog.