BMKG: “Be alert for potential extreme weather from heavy rains, hurricanes, to high tides”

BMKG Deputy of Meteorology Guswanto. (Photo: BMKG)

IO – The flash flood in the Regencies of Bogor and Sukabumi on Monday (21/09/2020), coupled with a 4-hour high-intensity rain that accumulated water to a height of 110 mm, is an example of extreme weather in our regions. Therefore, the Meteorological, Climatology, and Geophysics Agency (Badan Meteorologi, Klimatologi, dan Geofisika – “BMKG”) warns citizens that the transition of dry season to the rainy season is frequently marked by extreme weather. BMKG Deputy of Meteorology Guswanto stated that high-intensity rains with thunder and lightning might occur in several regions soon. “We predict that at the start of the 2020 rainy season in most of Indonesia will occur at the end of October until November 2020. Therefore, citizens should be alert for potential flooding of rivers at these times,” he stated in his press statement on Tuesday (22/09/2020). 

Guswanto further warns that a seasonal transition from dry to rainy will occur throughout September and October, wherein uneven rainfall of medium to heavy intensity may occur in short durations. “We need to be alert for potential extreme weather such as short-duration heavy rains that may be accompanied by thunder and/or lightning, strong winds, hurricanes, or even sleet during this seasonal transition,” he said. 

BMKG then announces the regions in Indonesia that might suffer from heavy rains in the upcoming weeks: Aceh, North Sumatra, West Sumatra, Riau, Jambi, South Sumatra, Lampung, West Java, Central Java, East Java, West Kalimantan, Central Kalimantan, East Kalimantan, South Kalimantan, North Kalimantan, North Sulawesi, Gorontalo, Central Sulawesi, West Sulawesi, Sulawesi South, Maluku, North Maluku, West Papua, and Papua. 

High Tides 

BMKG notes the that wind in the northern part of Indonesia blows in a Southeast-Southwest direction, at a speed of 8-20 knots, while wind in the South blows East-Southeast with a speed of 8-25 knots. The highest wind speeds are recorded in the waters of Enggano Island, the western waters of Lampung, the southern part of Sunda Straits, the southern waters of Banten, and the eastern part of Arafuru Sea. This will cause waves to rise to heights of 1.25 to 2.5 m in some waters, such as the eastern waters of Simeulue Islands and Mentawai Islands, the southern part of Bay of Lampung, the northern part of Sawu Sea, the Ombai Straits, the Natuna Sea, the eastern waters of Bintan Islands and Lingga Islands, the Gelasa Straits, the waters of Belitung Island, the Karimata Straits, the Java Sea, the northern waters East Java and Kangean Islands, the southern waters of Kalimantan, the southern and central parts of Makassar Straits, the waters of Kotabaru, the Bali Sea and Sumbawa Sea, the waters of Selayar Islands, the southern part of the Bay of Bone, the Flores Sea, and the waters of Baubau and Wakatobi Islands. 

Other areas that will be affected include the Bay of Tolo, the southern waters of Banggai Islands and Sula Islands, the Maluku Sea, the waters Bitung and Sitaro Islands, the waters of Sangihe Islands and Talaud Islands, the central and eastern part of the Sulawesi Sea, the eastern waters of Halmahera Islands, the Halmahera Sea, the southern waters of Buru, Ambon, and Seram Islands, the Seram Sea, the Banda Sea, the waters of Sermata Islands and Tanimbar Islands, the waters of Kei Islands and Aru Islands, the Arafuru Sea, the southern waters of Misool Island and Sorong-Fakfak, the northern waters of West Papua and Biak, and the Pacific Ocean in the north of Halmahera and Jayapura. 

High tides in a 2.5 to 4 m tall range might occur in other Indonesian waters, including the northern waters of Sabang, the western waters of Aceh and Mentawai Islands, the waters of Bengkulu, the western waters of Lampung, in the Indian Ocean in the west of Aceh and Nias, the western and southern parts of Sunda Straits, in the southern waters of Java and Sumba Islands, the southern part of the Bali Straits, Lombok Straits, and Alas Straits, in the southern part of Sape Straits, the western part of Sumba Straits, the southern waters of Sawu Island and Rotte-Kupang Islands, the southern part of Sawu Sea, and in the Indian Ocean in the south of Bali and West Nusa Tenggara. Extremely high waves with a height range of 4 to 6 m tall may occur in the western waters of Enggano Island, in the Indian Ocean in the west of Mentawai and Lampung, and in the Indian Ocean in the south of Java. 

Such potential high tides in these regions might threaten sailing safety. Therefore, the BMKG requests citizens to be constantly alert, especially for fishermen, sailors, and travelers who use vessels such as fishing boats (against wind speeds exceeding 15 knots and tide heights above 1.25 m), barges (against wind speeds exceeding 16 knots and tide heights above 1.5 m), ferry boats (against wind speeds exceeding 21 knots and tide heights above 2.5 m), and large ships such as cargo ships and pleasure ships (against wind speeds exceeding 27 knots and tide heights above 4.0 m). (dan)