BMKG: Heavy Rain May Trigger Floods, Landslide in N. Sumatra on Wednesday

BMKG: Heavy Rain May Trigger Floods, Landslide in N. Sumatra on Wednesday

BMKG – Indonesia’s Meteorology, Climatology, and Geophysics Agency (BMKG) has issued a caution to residents in specific regions of North Sumatra, urging them to remain prepared for potential flooding and landslides on Wednesday, June 24, 2026. The agency highlighted that intense precipitation, combined with lightning and strong gusts, could impact both the western and eastern slopes of the province.

Forecast Details

BMKG forecaster Endah Paramitha, based at the Region I Meteorological Station in Medan, noted that the region is expected to experience intermittent rainfall throughout the day. The advisory emphasized the need for vigilance, as such weather conditions could lead to localized disasters.

“Residents should stay alert to the possibility of rain accompanied by lightning and strong winds in the western and eastern slopes of North Sumatra, which may cause floods and landslides,” Endah stated on Tuesday.

Factors Contributing to Rainfall

The occurrence of rain is attributed to several meteorological phenomena. Endah explained that wind convergence zones around North Sumatra are fostering cloud development in multiple locations. Additionally, a shearline—a shift in wind direction—supports upward air movement, further promoting rain cloud formation.

Active Kelvin Wave activity over the northern part of Sumatra is also playing a role in enhancing convective clouds. These factors collectively contribute to the region’s unstable weather patterns, which are conducive to localized rainfall.

Expected Weather Conditions

On Wednesday morning, BMKG predicts cloudy skies and light rain across North Sumatra. From midday to evening, moderate precipitation is likely in Deli Serdang, Langkat, North Labuhanbatu, Simalungun, and surrounding areas. Nighttime rain is anticipated in several regions, with Labuhanbatu, North Labuhanbatu, and Mandailing Natal facing possible moderate downpours.

By early Thursday, most parts of the province are expected to return to cloudy conditions. Temperatures will range from 15 to 31 degrees Celsius, while humidity levels are projected to reach 78–99 percent. Winds will blow from the south to southwest at speeds of 3–7 kilometers per hour.

Read: Why Has Indonesia Seen Recent Rainfall During the Dry Season? Click here to get the latest news updates from Tempo on Google News.