Severe Tropical Storm Neoguri (25W) – Tropical Cyclone Advisory #19: 1200 UTC 26 September 2025

…Neoguri on the move again and forecast to strengthen as it undergoes extratropical transition…

Current storm information:

• Position: 31.4°N 155.5°E

• Movement: E at 10 knots (20 km/h)

• Intensity: 60 knots (110 km/h)

• Central pressure: 980 hPa

Trend:

• Some strengthening is forecast during the next 24 hours, and Neoguri will likely become a hurricane-force post-tropical cyclone late Sunday.

Discussion:

After a long, long period of going nowhere fast, Neoguri has finally begun moving eastward under the influence of an approaching frontal system. Despite the front’s close proximity and Neoguri moving back over its own cold wake, the tropical cyclone remains fairly well organized. Neoguri sports a compact and symmetric central dense overcast with decently cold cloud tops, and convective hot towers are flaring around the center, suggesting the presence of an eyewall. In fact, microwave satellite imagery depicts this eyewall fairly clearly, though it isn’t completely surrounding the center. The intensity is increased to 60 knots, based on Dvorak fixes ranging from T3.5 to T4.0 and a recent RCM-2 SAR pass that indicated winds of 55 to 60 knots south of the center.

Although the environment Neoguri is currently in is actually somewhat favorable for strengthening, the approaching frontal system will cause a different sort of strengthening. There is some very dry and cool air behind this front, and as the front overtakes Neoguri’s circulation over the weekend, it should impart some significant baroclinic energy and cause Neoguri to rapidly strengthen as it becomes a post-tropical cyclone. Neoguri is then forecast to weaken almost as quickly as it strengthened, and its circulation will likely be absorbed by a larger extratropical low south of Alaska on Wednesday.

Forecast positions and maximum winds

• 000 hrs: 31.4°N 155.5°E – 60 kts

• 012 hrs: 32.6°N 158.5°E – 65 kts

• 024 hrs: 34.5°N 162.2°E – 75 kts

• 048 hrs: 41.3°N 172.2°E – 80 kts Post-tropical/extratropical

• 072 hrs: 44.8°N 179.5°W – 60 kts Post-tropical/extratropical

• 096 hrs: 48.5°N 166.8°W – 35 kts Post-tropical/extratropical

• 120 hrs: Absorbed by larger extratropical low