摘要
利用南疆西部2000—2020年暖季(5—9月)多源气象资料,通过箱线图的形式对冰雹(102次)和短时强降水(159次),以及特强强对流个例的关键环境参数和预报阈值进行讨论。结果表明:(1)850和500 hPa的温差(△T_(85))、地面至700 hPa露点温度(△Td_(sur7))、大气可降水量(P·W)和暖云层厚度等关键参数的分布特征可以区分短时强降水和冰雹。短时强降水和冰雹对应参数的最低阈值:850和500 hPa温差分别为29、31℃、地面至700 hPa露点温度分别为4和-3℃、对流有效位能分别为1152和1470 J·kg^(-1)、0~6 km垂直风切变分别为4.0和7.0 m·s^(-1)。(2)强降水暖云层厚度最低阈值为1.2 km。冰雹适宜的融化层高度在3.5~4.3 km。(3)特强强对流天气主要体现在地面至700 hPa露点温度(△Td_(sur7))和大气降水量(P·W)增大、对流有效位能(CAPE)增大、有效抑制(CIN)减小和0~6 km垂直风切变增强。同时,对南疆西部强对流天气短临预报的潜势进行初探,为本地分类强对流天气智能网格预报奠定基础。
Using the multi-source meteorological data of the warm season(from May to September)in the western part of southern Xinjiang in the past 20 years,the distribution characteristics and forecast thresholds of key environmental parameters of hail(102 times)and short-term heavy precipitation(159 times)cases and extremely strong severe convection cases above is discussed in the form of boxplot.The results show as follows.(1)we can distinguish between hail and short-term heavy precipitation by the distribution characteristics of key parameters such as the temperature difference between 850 hPa and 500 hPa(shorthand forΔT_(85)),the dew point temperature difference between ground and 700 hPa(shorthand forΔTd_(sur7)),atmospheric precipitable water,and warm cloud thickness.There exists minimum threshold of each parameter corresponding to short-term heavy precipitation and hail,respectively:29℃and 31℃of theΔT_(85),4℃and-3℃of theΔTd_(sur7),1152 J·kg^(-1)and 1470 J·kg^(-1)of the convective available potential energy(shorthand for CAPE),4.0 m·s^(-1)and7.0 m·s^(-1)of 0~6 km vertical wind shear.(2)the minimum threshold of warm cloud thickness for heavy rainfall is 1.2 km,and the suitable melting layer height is 3.5~4.3 km for hail.(3)the extremely strong severe convection cases,different from the above parameter conditions,are mainly reflected in the increase of water vapor conditions,the increase of the CAPE,the decrease of convective inhibition and the enhancement of 0~6 km vertical wind shear.Meanwhile,this study conducts a preliminary exploration on the potential of severe convective weather short-term and imminent forecasting in the west of southern Xinjiang,laying a foundation for the local classification of severe convective weather intelligent grid forecasting.
作者
黄艳
安克武
唐鹏
HUANG Yan;AN Kewu;TANG Peng(Hotan Meteorological Observatory,Hotan 844000,China;Xinjiang Meteorological Technology and Equipment Support Center,Urumqi 830002,China)
出处
《沙漠与绿洲气象》
2022年第6期11-17,共7页
Desert and Oasis Meteorology
基金
新疆维吾尔自治区自然科学基金(2021D01A15)
中国气象局大气探测重点开放实验室重点项目(2021KLAS03Z)
国家自然科学基金(41965002)。
关键词
南疆西部
短时强降水和冰雹
环境参数
预报阈值
the west of southern Xinjiang
short-term heavy precipitation and hail
environmental parameter
forecast threshold
