Source: Kompas
Date: May 31, 2021

Rain in several areas in Indonesia may occur in the next week. Some regions need to be aware of floods.

JAKARTA, KOMPAS - Tropical cyclone seeds grow in the southwestern Pacific Ocean, in the east-southeast of the Philippines. At the same time, Kelvin and Rossby wave activity grew over Indonesian territory. This combination has the potential to trigger heavy rains in several regions in Indonesia for the next week.

This early warning of extreme weather in Indonesia was conveyed by the Deputy for Meteorology of the Meteorology, Climatology and Geophysics Agency (BMKG) Guswanto, Monday (31/5/2021).

The centre of low pressure in the Pacific Ocean which is named the 04W system is located at the coordinates of 5.9 North Latitude and 133.1 East Longitude with a maximum wind speed of 30 knots or 56 kilometres per hour and a minimum air pressure reaching 1004 hPa.

Based on the monitoring of Himawari-8 weather satellite imagery, significant and persistent convective cloud activity was identified in the last six hours around the 04W System. "The movement of the 04W system shows that it is moving west to the northwest away from Indonesian territory with the potential to grow into a tropical cyclone," said Guswanto.

Guswanto added the analysis of ocean-atmosphere dynamics shows the existence of Kelvin wave activity around Sumatra, Kalimantan, Sulawesi and northern Papua. Meanwhile, the Equatorial Rossby wave is active around the Java region and the Pacific Ocean east of the Philippines.

This condition triggers a slowdown and bends in the wind in several areas, which triggers the formation of potential rain clouds, which can cause the potential for moderate to heavy rain intensity. The potential for moderate to heavy rain on June 1, 2021 occurs in Aceh, West Sumatra, Jambi, Bengkulu, South Sumatra, Bangka Belitung Islands, Banten, DKI Jakarta, West Java, Central Java, East Java, Central Kalimantan, Central Sulawesi, West Sulawesi, South Sulawesi, Maluku, West Papua and Papua.

Meanwhile, on 2-4 June 2021, the areas with a chance of rain include Aceh, North Sumatra, West Sumatra, Riau Islands, Jambi, Bengkulu, Lampung, Banten, West Kalimantan, Central Kalimantan, North Kalimantan, East Kalimantan, North Sulawesi, Central Sulawesi. , West Sulawesi, South Sulawesi, North Maluku, Maluku, West Papua, and Papua.

Meanwhile, on June 5-7, 2021, rain will likely occur in Aceh, Riau Islands, Bengkulu, West Kalimantan, North Kalimantan, North Sulawesi, Gorontalo, Central Sulawesi, West Sulawesi, South Sulawesi, Southeast Sulawesi, North Maluku, Maluku, West Papua. , and Papua.

Based on the weather forecast based on the impact of flooding with the alert category, it is likely to occur in the next two days in Aceh, South Sumatra, West Java, Central Kalimantan, West Kalimantan, North Kalimantan, Central Sulawesi and Papua. The areas potentially affected by the district to sub-district scale can be accessed on the https://signature.bmkg.go.id page.

Jabodetabek area

Head of the Climate and Air Quality Information Subdivision of BMKG Siswanto said that rain still has a chance to occur in parts of the Jabodetabek area until mid-June 2021 even though it is accumulatively low. "From the monitoring and analysis of the Jabodetabek rain, generally this area in the last two weeks has still received quite frequent rain with varying intensities," he said.

Siswanto added, this area should be in the transition from the season to the dry season. However, the presence of atmospheric waves still keeps conditions quite wet these days.

Based on the BMKG's estimated dry season, he continued, East Jakarta, southern Jakarta, South Tangerang, Lebak, Depok, and parts of Bogor will only enter the dry season at the end of May to mid-June. Meanwhile, Cilegon, Serang, central Tangerang, Tangerang City, Central Jakarta, West Jakarta, northern South Jakarta, and the western part of East Jakarta are predicted to enter the dry season in the first 1-3 months of May. As for East Serang, northern Tangerang, northern Jakarta, Bekasi, and North Karawang are predicted to have entered the dry season from late March to mid-April.