Heavy Rainfall Expected in the Philippines, Korean Peninsula, and Other Regions

Under the influence of Typhoon Wipha (the 6th typhoon of 2005) (Figure 1), parts of the Philippines, northern Vietnam, Laos, Cambodia are expected to experience heavy to torrential rain from July 18 to 23. Some localities may see severe downpours accompanied by severe convective weather such as short-duration heavy rainfall, thunderstorms, and gales. Accumulated rainfall in most of the above areas will reach 60–110 mm, with 120–170 mm in some regions. Localities including western Ilocos, western Central Luzon, western Southern Tagalog, western Western Visayas, and eastern Bicol in the Philippines, as well as Hanoi in Vietnam, and southern Bokeo Province and southwestern Oudomxay Province in Laos, may receive over 300 mm (Figure 2). Northern Philippines, northern Vietnam, and northern Laos will successively experience force 6–8 gales, with gusts reaching force 9–10.

Additionally, from July 18 to 21, under the combined influence of an eastward-moving cold air mass and the Western Pacific Subtropical High (Figure 3), most of the Korean Peninsula and parts of Hokkaido, Japan, will experience heavy to torrential rain. Some localities may see severe downpours accompanied by severe convective weather such as short-duration heavy rainfall, thunderstorms, gales, and hail. Accumulated rainfall in most of the above areas will reach 30–60 mm, with 80–120 mm in some regions (Figure 4).

Attention should be paid to secondary disasters such as flooding, landslides, mudslides, and urban waterlogging that may be triggered by the heavy rain and strong winds in the aforementioned regions.

Figure 1 Typhoon Track Probability Forecast (BJT, 08:00 July 18, 2025 – 08:00 July 23, 2025)

Figure 2 Forecasted Accumulated Precipitation in the Philippines and Surrounding Areas from July 18 to 23, 2025 (unit: mm)

Figure 3  500 hPa Geopotential Height (contours, units: dagpm) and 850 hPa Wind Field (wind barbs, units: m/s) at 12:00 UTC on July 20, 2025

Figure 4 Forecasted Accumulated Precipitation for the Korean Peninsula and Surrounding Areas from July 18-21, 2025 (unit: mm)

Author: Yang Jing, Liu Da                               Reviewer: Cai Xiangning 

English reviewer:Wang Yi                                                                       Issue approver:Dai Kan