Analysis of Weather Change Using Himawari-8 Satellite Image with 24-Hours Microphysics RGB and Convective Available Potential Energy Method (Study Case: Flood Central Kalimantan 18-24 August 2021)

Abstract

Rain with light heavy intensity hit Central Kalimantan Province starting on Thursday (19/8/2021), and submerged 13 sub-districts in Katingan Regency, Central Kalimantan. The study analyzed the weather during heavy rains using reanalyzed data from Copernicus ECMWF, namely Convective Available Potential Energy (CAPE) which was then processed into a map and supported by data from the Himawari-8 satellite to analyze Streamline, Time series, 24-Hours Microphysics RGB starting on the 18th. −24 August 2021. On 18 August 2021 Cumulonimbus clouds were detected in the Katingan Regency area, with the highest cloud top temperature reaching −67°C whereas when the temperature was above −60 °C, this indicates that these clouds are Cumulonimbus convective clouds with a high peak, and the highest CAPE value is 1001–1500 J/kg which means it is categorized as moderate energy. On August 19, 2021, Cumulonimbus clouds were detected, the highest cloud top temperature reached −70°C, and the CAPE value was 1501-2100 J/kg which means it is categorized as moderately strong energy. On August 20, 2021, Cumulonimbus clouds were detected, the highest cloud top temperature reached −78°C, and the CAPE value was 2101-3545.6 J/kg which means it is categorized as strong energy. On August 21, there were thin Cumulonimbus clouds that did not spread evenly, the highest cloud top temperature reached −38°C where the temperature was already below the freezing level and already contained cloud crystals, and the CAPE value in most areas of Katingan Regency was 200–400 J/kg which means it is categorized as weak energy. On August 22, 2021, Cumulonimbus clouds were detected, the highest cloud top temperature reached −77°C, and the CAPE value was 701–1400 J/kg which means it is categorized as moderately weak energy. On August 23, there were no Cumulonimbus clouds in the Katingan Regency area, the highest cloud top temperature reached −37°C, and the CAPE value in most areas of the Katingan Regency was 0-600 J/kg which means it is categorized as weak energy. On August 24, 2021, Cumulonimbus clouds were detected in the Katingan Regency area, the highest cloud top temperature reached −78°C, and the CAPE value in the Katingan Regency area was 2102-3474.5 J/kg which means it is categorized as strong energy. Streamline analysis dated 18,19,20,22,24 in the 850 mb layer above the Katingan Regency area, there is a Shearline. Meanwhile, on 21 and 23 August 2021, the wind over Katingan Regency looked straight and there were no very significant turns so on 21 and 23 August 2021 there was no formation or formation of very thin convective clouds.