Abstract:
Based on T213 forecast data, the strong cold wave weather process on April 18, 2008 in Shihezi reclamation areas in North Slope of Tianshan Mountain, Xinjiang province was analyzed, and its circumfluence background, influencing system and physical fields were studied. The results indicate that the main reason of this weather process is that the ridge of the Caspian Sea and Black Sea expands and moves to eastward and splices with Eastern-Europe’s ridge and veers. Northeasterly wind belt in front of the ridge develops and strengthens, which induces Tamil peninsula’s northeast cold air to turn to southwest and to reach horizontal trough, consequently compels horizontal trough to turn and to develop intensively southeast pressure, finally forms the rush-flow in the high sky, strong frontal zone and cold high pressure. The high pressure ridge partially collapsed to the southeast leads to middle-high latitudinal strong cold air turning to southeast on a large scale, and strong cold wave weather is formed. The convergence of southwestern jet and cold air comes into being the strong dynamic convergence and water vapor convergence, which is important to the forming of torrential storm. Torrential storm occurs in stronger frontal zone of energy, high humid region and water vapor flux convergence region.