Based on the hourly precipitation observation data of 105 national stations and 1240 regional stations and 8 Doppler weather radars data in Xinjiang from 2010 to 2018, from the perspective of operational forecasting, the definition of shortterm heavy precipitation process in Xinjiang was proposed and 468 shortterm heavy precipitation processes were selected, and circulation configuration of influence system and radar observation characteristics were analyzed. The results show that there were four kinds of influence systems including the central Asia trough (vortex), the west Siberian trough (vortex) and low level northwest jet stream. The convective storms resulting in shortterm heavy rainfall were combined enhancement type, train effect type and isolated convective cell type, and the combined enhancement type was 45.1%, isolated convective cell type was 34.8%, and the train effect type was 20.2%, respectively. The parameter thresholds of the maximum reflectivity factor intensity (Zmax), the maximum height of the strong echo (Dmax), the maximum height of the echo top (ET) and the maximum vertical accumulated liquid water content (VIL) observed by Doppler radar during shortterm heavy precipitation processes in southern Xinjiang were less than those in northern Xinjiang, and in Yili prefecture they were largest and in Aksu they were smallest. The shortterm heavy precipitation in Yili prefecture was dominated by low centroid echo, while in other regions it was dominated by low centroid and high centroid echo.

Based on the observation data during the period of the experiment with ‘theoretical study and observations of water and energy exchange and planetary boundary layer on inhomogeneous underlying surface in oasis system’, the influences of surface temperature difference between desert and oasis, buoyancy frequency (Brunt-Visl frequency) and background wind velocity on oasis effect were discussed by a series of idealized numerical tests of BLASIUS (boundary layer above stationary, inhomogeneous uneven surface) model with high resolution and complex terrain. The results show that the cold island effect and humid island effect enhanced with the increase of surface temperature difference between oasis and desert, and the enhancing action mainly occurred below 500 m over the ground. The horizontal range of ‘cold island’ over oasis enlarged and the vertical height of ‘humid island’ decreased with increase of surface temperature difference. The influence on ‘humid island effect’ was about an hour later than that on ‘cold island effect’. The updraft airflow over the oasis increased and the vertical velocity increased over the transition area above 1.5 km height with increase of buoyancy frequency. The symmetry of vertical circulation between oasis and desert decreased with increase of initial background wind speed, and the height of circulation center decreased and the strength weakened.

Based on monthly temperature, sea surface temperature over Pacific, 500 hPa geopotential height field and circulation data in July and August from 53 stations in Northeast China during 1961 - 2004, the temporal and spatial temperature pattern over Northeast China from July to August in recent 44 yearswas analyzed using Emp iricalOrthogonal Function ( EOF) analysismethod. The canonical correlation analysis (CCA) method was used to forecast and testmonthly temperature in midsummer. Results show that the spatial pattern ofmonthly temperature in July and August ismainly classified into three types: the whole region consistency, north - south type and east - west type. The CCA method handles better in p rediction of monthly temperature in July and August of 2005 and 2006 in Northeast China.