Tropical Depression 19W (Isang) – Tropical Cyclone Advisory #2: 1500 UTC 22 August 2025

Depression moves off the western coast of Luzon and forecast to strengthen.

Author

Will Weaver
August 22, 2025

…Depression moves off the western coast of Luzon and forecast to strengthen…

Himawari-9 infrared satellite image (Weathernerds)

Current storm information:

  • Position: 16.9°N 118.6°E

  • Movement: W at 15 knots (25 km/h)

  • Intensity: 30 knots (55 km/h)

  • Central pressure: 1004 hPa

Trend:

  • Some strengthening is forecast during the next 24 hours and the depression will likely become a tropical storm on Saturday.

Watches and warnings:

PAGASA wind signal map (click to enlarge)

  • TCWS #1 (Philippines): All of mainland Luzon north of a line extending from Pangasinan to northern Nueva Ecija to Aurora; Babuyan Islands

Hazards affecting land:

  • Conditions over mainland Luzon should gradually improve during the next several hours, although periods of moderate to heavy rain remain possible.

  • Interests in Hainan Island and central Vietnam should monitor the progress of 19W. The system could bring typhoon conditions to those areas on Sunday and Monday.

Discussion:

The depression - now Tropical Depression 19W - has quickly made its way across central Luzon and is now off the island’s west coast. The depression is a bit better organized, with a large area of flaring convection expanding eastward to obscure the low-level circulation. This seems to be corresponding to a decrease in shear as 19W moves out of the area of strong northeasterly flow. This convection is mostly formless, although some bands can be noted to the south and west of the center. Although surface observations are not particularly impressive, the intensity remains 30 kts based on consensus T2.0 Dvorak fixes.

The forecast is generally unchanged. A strengthening ridge to the northeast is expected to steer TD 19W west to west-northwestward during the next few days. As 19W moves across the South China Sea, the environment is expected to become even more favorable, with low shear and very warm SSTs, and steady strengthening is forecast over the weekend. In fact, rapid intensification cannot be ruled out as RIPA rapid intensification guidance indicates a rather high chance of an increase of 65 kts during the next 72 hours. 19W will likely become a tropical storm during the next 12 to 24 hours, and it will likely become a typhoon on Sunday evening as it passes south of Hainan Island. By that point, land interaction will probably cause the intensity to level off, but 19W is still likely to be a typhoon by the time it makes landfall in central Vietnam on Monday. Rapid weakening is likely following landfall, and 19W should degenerate into a broad area of low pressure over northern Thailand on Tuesday.

Forecast positions and maximum winds

  • 00 hrs: 16.9°N 118.6°E – 30 kts

  • 12 hrs: 17.0°N 116.5°E – 35 kts

  • 24 hrs: 17.3°N 114.8°E – 50 kts

  • 48 hrs: 18.0°N 109.0°E – 65 kts

  • 72 hrs: 18.5°N 105.7°E – 75 kts

  • 96 hrs: 19.1°N 101.3°E – 70 kts inland

  • 120 hrs: Dissipated

JTWC forecast map

One last thing…

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