The Meteorology, Climatology and Geophysics Agency (BMKG) has issued a warning for potential extreme weather particularly heavy rains in a number of provinces between August 15 and 20, 2021.
Among provinces expected to experience moderate to heavy rains were Aceh, North Sumatra, Riau, Riau Islands, West Sumatra, Jambi, Bengkulu, South Sumatra, Bangka Belitung Islands, Banten, West Java, Central Java, West Kalimantan, Central Kalimantan, East Kalimantan, North Kalimantan, South Kalimantan, North Sulawesi, Gorontalo, Central Sulawesi, West Sulawesi, South Sulawesi, Southeast Sulawesi, North Maluku, Maluku, West Papua and Papua, BMKG Deputy for Meteorology Guswanto said in a press release here on Sunday.
Increased activity of the Madden Julian Oscillation (MJO) and the Equatorial Rossby wave would likely induce rain cloud to develop, he added.
“The MJO and the Equatorial Rossby Wave are atmospheric dynamics phenomena that indicate the potential for the growth of rain cloud on a wide scale around the regions they pass through,” he said.
The MJO phenomenon moves from the Indian Ocean to the Pacific Ocean through the Indonesian territory with a cycle of 30 days to 40 days, while the Rossby Wave phenomenon moves from the Pacific Ocean to the Indian Ocean by passing through Indonesian territory, he explained
“Just like the MJO, when the Rossby Wave is active in Indonesia, it can contribute to increasing the growth of rain clouds in several parts of Indonesia,” he said.
In addition, BMKG also observed the presence of confluence areas and a slowing of wind speed (convergence) that extends in the western waters of West Sumatra and from Riau to North Sumatra which can contribute to increased rain cloud growth.
“The dynamics of the atmosphere has the potential to increase the growth of rain clouds in the next one week in several parts of Indonesia,” he said.
The BMKG also warns of potential hydrometeorological disasters such as floods or flash floods due to heavy rains in Riau, West Sumatra and Jambi for the next five days, Guswanto added. (drt)