Abstract:Based on GMS—5 hourly infrared numerical nephogram,10 rainstorm and hail processes are analyzed respectively in summe
from 1998 to 2001. The research shows that there are obviously similarities and differences on scales,shape, intensity, occurrenc
time and mature time and life span of meso-scale cloud cluster. These results are important for monitoring and warning of rainstorm
and hail processes.

Severe convective weather is more frequent in north oasis of AKSU.Thought both rain storm and hail are severe convective
weather，their effect systems，features of physics quantities are remarkable different.（1）Cold air impacting on rain storm is wet and
weak，but it is strong and dry which impacts on hail；（2）The upper troposphere jet is weake runder rainstorm condition than that
under hail condition，and there is an east lower troposphere jet where there is a rainstorm；（3）They are both in wet tongue，but the
humidity in rainstorm are aishigher than that in hail area，and there is obvious water vapor transmission from 850 hPa to 500 hPa，especially lower jet transports adequate water vapor to rainstorm area. There are strong moisture convergence in rainstorm and hail area，
and it is stronger in rainstorm area；（4）The reare strong ascending motion and severe instability，the ascending motion is stronger at
850 hPa in hail area，but it is stronger at 500 hPa in rainstorm area，and the instability is more severe in rainstorm area.