Abstract: This paper uses ground truth measurement data, normal weather chart, satellite cloud images and T- LnP map meteorological data, by analysising the weather process of visibility break affected advection fog on 18th April 2012 in western Sichuan Basin in Qionglai airport, and trying to excavate the weather character, which provides some scientific theory clues and technical foundation support. for the actual short- time fine forecast and aviation meteorological guarantee the core competence of ascension.