Analysis of causes of
localized heavy rains
in Korean and countermeasures
preiction variables of heavy rainfall
Variables that can be used to predict heavy rainfall
CAPE
Quantification of the potential energy that can generate and strengthen convection from the vertical distribution of temperature and water vapor
Temperture & potential temperature advection
Temperature Advection: Temperature change caused by horizontal movement of the wind.
- divided into cold advection and warm advection
The convergence of warm currents leads to vigorous convection at the convergence point
Cloud thickness
: distance from cloud base to cloud top
It influences the intensity of precipitation.
Deep clouds with a thickness of 10 km have a tendency to produce heavier rainfall.
SRH
The quantification of the possibility of a cyclonic rotation in a low-pressure system in a storm.
Useful for supercell and tornado forecasting tools.
If it exceeds 150 m^2s^-2, there is a high possibility of the occurrence of a strong convective storm.
Integrated liquid water
The amount of liquid present in the spatial mountainous area of the concentrated heavy rain occurrence point, utilized for hail size or storm prediction.
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Instability index (KI/SSI/LI)
The degree of atmospheric instability
- KI : Diagnosis of Heavy Rainfall and Thunderstorms during the Influence of Summer Monsoon in the Oceanic Tropical Convergence Zone
- SSI Diagnosis of atmospheric instability, error occurs when prediction inversion layer exists and water vapor decreases sharply:
- LI : Developed to modify SSI
3 cases
When rain continues to fall and suddenly intensifies
=> line-type convection system
A case where light precipitation rapidly intensified
=> shallow convection type of convecion system
A case of heavy rainfall caused by a localized convective cell
=> heavy rainfall by localized convection cell
case 1
KI
SSI
LI
Cloud thinckness
Cloud thickness greater than 10 km at almost all times
Integrated liquid water
It increases rapidly before rain begins and then decreases rapidly when rain falls.
CAPE
Increased before heavy rainfall and reached the maximum value
Temperature & potential temperature advection
At the onset of precipitation, the low-temperature, low potential temperature advection has its maximum when precipitation is at its maximum.
Instability index
KI : a value of 30 or greater
SSI : Decreases at the onset of precipitation and increases as precipitation increases
LI : High at the beginning of precipitation, then gradually lower
SRH
Has a value of 150 m^2/s^2 with high probability of convective storm occurrence before heavy rain
case 2
KI
SSI
LI
Cloud thickness
The cloud is relatively thin, about 5 km thick.
Integrated liquid water
It increases rapidly before rain begins and then decreases rapidly when rain falls.
CAPE
After reaching the maximum value before heavy rain, it decreased as torrential rain fell
Temperature & potential temperature advection
The advection value, which was the minimum before the heavy rain, rapidly increased and reached the maximum value when the precipitation was maximum.
Instability index
KI : highest before precipitation, then continuously decreasing
SSI : Continuous increase before heavy rain
LI : increased gradually before heavy rain
SRH
Has a value of 150 m^2/s^2 with high probability of convective storm occurrence before heavy rain
case 3
KI
SSI
LI
Cloud thickness
Cloud thickness changed
Integrated liquid water
It increases rapidly before rain begins and then decreases rapidly when rain falls.
CAPE
Has a maximum value 5 hours before the heavy rain and gradually decreases
Temperature & potential temperature advection
It increased rapidly before the occurrence of torrential rains, and then decreased rapidly during the heavy rains, reaching the minimum value.
Instability index
KI : Decrease before heavy rain
SSI : Decrease before heavy rain
LI : Decreases rapidly at the onset of precipitation, increases gradually before torrential rain
SRH
Has a value of 150 m^2/s^2 with high probability of convective storm occurrence before heavy rain
'It is important to enhance accuracy by utilizing additional variables rather than relying on a single variable, as the predictor variable may vary with each concentrated heavy rain event.'