Tropical Depression #15W – Tropical Cyclone Advisory #1: 1200 UTC 6 August 2025

…Tropical Depression 15W moving north-northwestward well away from any land areas… …Likely to become a remnant low on Thursday…

Current storm information:

• Position: 29.6°N 157.2°E

• Movement: NNW at 8 knots (15 km/h)

• Intensity: 25 knots (45 km/h)

• Central pressure: 990 hPa

Trend:

• Little change in strength is forecast during the next 24 hours, and the depression could become a remnant low on Thursday.

Discussion:

The minor tropical depression out in the far northeastern portion of the basin has developed a better defined circulation center during the past several hours, and JTWC has upgraded it to Tropical Depression 15W. Unfortunately for it, and much like Tropical Depression 14W (which partially gave rise to 15W), that circulation is pretty much all it has. The depression is producing minimal convection, consisting of one small band displaced well to the south of the circulation center by moderate to strong northeasterly shear. The intensity is 25 kts, based mainly on a recent HYSAT scatterometer pass and a T1.5 Dvorak fix from PGTW. KNES gave a “too weak” Dvorak fix.

Just like 14W, 15W won’t be around for long. The environment is expected to become even less favorable as the depression moves generally northward during the next day or two, with even stronger shear, drier air, and cooler SSTs ahead. These conditions will likely preclude any strengthening, and the dry air will likely result in 15W degenerating into a remnant low within the next 12 to 24 hours. The remnant low should dissipate ahead of an approaching front by Friday.

Forecast positions and maximum winds

• 00 hrs: 29.6°N 157.2°E – 25 kts

• 12 hrs: 31.4°N 156.9°E – 25 kts

• 24 hrs: 34.2°N 156.4°E – 25 kts Post-tropical/remnant low

• 48 hrs: Dissipated