Southeasterly high winds are forecasted by using WRF model and GFS data. Meanwhile, terrain sensitivity experiments are carried out. The results show that the WRF model has relatively strong capability of forecasting the starting time and duration of winds, wind speeds, etc. Terrain sensitivity experiments show that: (1) the altitude difference （about 300 m) between the Urumqi urban area and the airport has significant influence on wind speeds; (2) the strength of downward movement above the airport is in good correspondence with wind speeds; (3) the variation of wind speeds does not always keep step with the pressure gradient force at the ends of the valley. 〖JP2〗The high winds are the combined result of the low level downward transporting of momentum, tunnel effect, and downslope winds. The downward transporting of momentum mainly occurs below 2000 m (AMSL), 〖JP2〗while downslope winds occur below 935 m.