Page 96 - 《高原气象》2022年第6期

6 期 田付友等：中国中低海拔地区三类强对流天气环境条件的基本气候特征 1459
wind，and hail support the decision making in targeted preventative measures. A full understanding of the envi‐
ronmental characteristics and difference of classified convective weather phenomena forms the necessary basis of
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accurate forecasting and warning. The hourly rainfall greater than 20 mm·h ，thunderstorm-induced wind greater
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than 17. 2 m·s ，and the hail with maximum diameter greater than 5 mm are defined as short-duration heavy rain‐
fall，thunderstorm wind，and hail in the operational severe convective weather forecast of National Meteorologi‐
cal Center（NMC）. The hourly precipitation and hail data from 2002 to 2010，hourly thunderstorm wind data
from 2010 to 2014 over regions of China with the terrain height lower than 2500 m above mean sea level，and
NCEP FNL（National Center for Environmental Prediction，Global Final Analysis）data with spatial resolution
1°×1° and temporal resolution of 6-hour from 2002 to 2014 during the warm seasons from April and September
are collected to analyzed the features of and to categorized these three phenomena. Spatial and temporal matching
processes are applied by considering the difference in spatial and temporal resolution. Values of parameters at sta‐
tions obtained through a bilinear interpolation method. The environmental climatology of parameters representing
the environmental moisture content，water vapor saturation，instability conditions，low-level triggering condi‐
tions，height of characteristic temperature layer，and the density of scatter plots of parameters are investigated.
Results show that Southern China is hot spot for short-duration heavy rainfall. There are two high frequency re‐
gions for thunderstorm wind that locates at Southern China and central north of Northern China，separately. The
central north of Northern China also has the highest frequency of hail. For the annual cycle，short-duration heavy
rainfall mainly occurs during the summer seasons. There are also two peaks of thunderstorm wind in the end of
spring and summer. The single peak of hail is in late spring and early summer. For the average sounding，the
most obvious characteristic for short-duration heavy rainfall is the high relative humidity in all levels indicated by
small difference between temperature and dew-point temperature，while large differences between temperature
and dew-point temperature at lower levels exist in both thunderstorm wind and hail. Statistical results show obvi‐
ous differences in the total precipitable water（PWAT），relative humidity，temperature lapse rate，and height of
0 ℃ temperature above the sea surface（Z0）that distinguish the three different severe convective weather types.
The main PWAT range for short-duration heavy rainfall is between 50. 4 mm and 63. 4 mm，for thunderstorm
wind is between 19. 5 mm and 49. 8 mm，while for hail is between 13. 9 mm and 28. 1 mm. The PWAT medians
for the three convective weather phenomena are 56. 0，33. 4，and 22. 2 mm，respectively. Hail could be exclud‐
ed when PWAT is greater than 42. 3 mm. The environmental conditions among short-duration heavy rainfall and
thunderstorm wind and hail could also be distinguished by relative humidity to some degree. For the environmen‐
tal instability indicators，both the temperature lapse rate（TLR85）and the temperature difference between 850
hPa and 500 hPa（DT85）performance better than the best lifted index（BLI）and best convective available po‐
tential energy （BCAPE）. Short-duration heavy rainfall mainly happened in wet adiabatic environment with
TLR85 less than 5. 5 ℃ while most hail happened in stronger temperature lapse rate environment with TLR85
greater than 7. 0 ℃. For Z0，only less than 5% short-duration heavy rainfall and hail have similar Z0. But thun‐
derstorm wind overlaps with both short-duration heavy rainfall and hail. The performance of 0~6 km vertical
wind shear（SHR6）is better than both 0~1 km（SHR1）and 0~3 km vertical wind shear（SHR3）in distinguish‐
ing the three different convective weather phenomena. The environment with high PWAT，high saturation，and
high Z0 is favorable for short-duration heavy rainfall，while the environment with smaller PWAT，lower satura‐
tion，lower Z0，and higher temperature lapse rate is favorable for hail. There are two high density areas for thun‐
derstorm wind which overlaps with that for short-duration heavy rainfall and hail，respectively.
Key words：Environmental conditions；short-duration heavy rainfall；hail；thunderstorm wind；climatologic
characteristics