The Features Analysis Of Sleet-to-Snow Weather Process In Heilongjiang Province

This paper analyzes the weather distribution characteristics of sleet-to-snow in Heilongjiang province with the method of statistical analysis by using the conventional meteorological observation data from 2000 to 2015,the main conclusions are as follows:(1)The occurring of sleet-to-snow in Heilongjiang shows an upward trend in these years.The sleet-to-snow weather occurs mostly in March,April,October and November,therefore it is less frequently occurring in other months.It's mainly because the change of temperature……..(2)Analysis of spatial and temporal distribution of the sleet-to-snow weather in Heilongjiang province,it can be seen that sleet-to-snow weather mainly occurs in northern and eastern regions for the temperature in the north of Heilongjiang province is lower than other regions,which makes sleet turns to snow more possible.For the east of Heilongjiang province,the region is affected by southwest airflow and the Sea of Japan,so the occurrence rate of sleet-to-snow is higher than other regions in Heilongjiang province.(3)By analyzing the air sounding statistical observation data,it is concluded that the temperature more focused on the rangeof 850 h Pa,and high altitude temperature threshold is-3? to-8 ?,and the 850 hPa zero field temperature data is collected in the Meteorological Observatory of Heilongjiang Province,so 850 hPa is the key of forecast,the affect of the height of the zero layer is mostly concentrated on 850 hPa to 1000 hPa.(4)The ground temperature is more likely concentrated between-1 ? and 2 ? after analyzing the ground observation data,and the ground wind speed is generally smaller,which is more focused between 0 m/s and 6 m/s,accounts for 91% of the terminal times with northwind.By analyzing the distribution processes of three typical sleet-to-snow weather in Heilongjiangprovince in several aspects,such as the sky and the ground impact system,mesoscale analysis,quantity analysis,satellite cloud pictures and so on.The forecast indexes of sleet-to-snow in Heilongjiang province are sumarized.