Flash Flood Disasters Occur in Northern Nepal

Influenced by the southwest monsoon and orographic lifting along the southern foothills of the Himalayas, Nepal has experienced persistent rainfall over the past 10 days, with accumulated precipitation reaching heavy rain to intense rain levels (Figure 1). Additionally, driven by a plateau trough, southern Tibet, China (upstream of Nepal) has seen moderate to heavy rain, with localized heavy to intense downpours. As a result of both local and upstream rainfall, disasters such as flash floods and debris flows struck northern Nepal on August 26. Over the next three days, a monsoon depression located over northern India (Figure 2) is expected to continue bringing moderate to heavy rain to Nepal, with heavy to intense downpours in the south (Figure 3). Vigilance is advised against potential secondary disasters—including flash floods, landslides, and debris flows—that may be triggered again by the persistent heavy precipitation.

Figure 1. Real-time observation of accumulated station rainfall from August 16 to 25, 2026 (UTC)

Figure 2. Forecast of 850 hPa Geopotential Height (contours, units: dagpm) and 850 hPa Wind Field (barbs, units: m/s) at 12:00 UTC on August 26, 2026

Figure 3. Forecast of Accumulated Precipitation from 12:00 UTC on August 26, 2026 to 12:00 UTC on the 29th (Unit: mm)

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Author: Huo Da                                 Reviewer: Bao Yuanyuan 

English reviewer:Wang Yi                                                      Issue approver:Dai Kan