2015.10.10

Weather Charts

The hail broke out at 11 a.m. in Gwangjin-gu, Seoul.
The cut-off low with cold core forms a type of southward movement from the northwest.
If the cut-off low is located above the Korean Peninsula, there is a possibility of atmospheric instability due to the temperature difference between the upper and lower levels.
Upper level temperature is about -25 to -20 degrees Celsius (There is a -15 degrees line nearby.)

The surface temperature is 6 degrees Celsius, and the difference between 500hPa and the surface is about 26 degrees.
There is a front. Warm air is dominant before this cold front passes, and as the cold air moves southward as it passes, there is also a continuous and horizontal temperature gradient. Then the instability increases and hail occurs. It usually occurs in autumn.
The temperature difference between the upper and lower floors increases, resulting in severe atmospheric instability.