Severe Tropical Storm Neoguri (25W) – Tropical Cyclone Advisory #16: 1200 UTC 25 September 2025

…Neoguri taking a jump to the left and then a step to the right…

Current storm information:

• Position: 32.3°N 154.9°E

• Movement: WSW at 11 knots (20 km/h)

• Intensity: 60 knots (110 km/h)

• Central pressure: 979 hPa

Trend:

• Little change in strength is likely during the next 24 hours.

Discussion:

Neoguri is currently doing the Time Warp over the northern Pacific, as the tropical cyclone is now moving west-southwestward under the influence of a small ridge of high pressure that has built to the north. There is not much convection left - other than a small area of ragged, formless convection to the north of the center, Neoguri is mostly devoid of convection. The surface circulation is fully exposed and embedded in cool, dry air, and there are signs that a cold front is developing to the south. Cyclone phase diagrams indicate that Neoguri’s warm core is becoming asymmetric, which is an indication of impending extratropical transition. Given the overall lack of convection, most satellite-based estimates of Neoguri’s intensity are too low. The intensity is lowered to 60 kts based on a RCM-2 SAR pass that indicated winds of about 58 kts, and this is also backed up by scatterometer data.

The frontal system that will finally sweep Neoguri away is approaching from the northwest. This front will erode the small ridge currently steering Neoguri to the west-southwest, and the tropical cyclone is forecast to pivot back to the east-northeast, then northeast during the next day or two. Much colder air is behind this front, and very strong baroclinic forcing will cause Neoguri to strengthen as it undergoes extratropical transition. Neoguri is expected to become a powerful hurricane-force extratropical cyclone by Sunday evening as it races northeastward, and it will likely remain a hurricane-force low as it exits the basin on Monday. 

Neoguri is expected to remain a powerful extratropical low as it passes very near the Aleutian Islands and the Alaska Peninsula on Tuesday and Wednesday, and interests there should closely monitor its progress. For additional information, and possible warnings, refer to products from the National Weather Service.

Forecast positions and maximum winds

• 00 hrs: 32.3°N 154.9°E – 55 kts

• 12 hrs: 32.0°N 154.5°E – 55 kts

• 24 hrs: 31.6°N 153.9°E – 60 kts

• 48 hrs: 33.0°N 158.6°E – 70 kts

• 72 hrs: 39.2°N 167.1°E – 70 kts Post-tropical/extratropical

• 96 hrs: 47.5°N 178.3°E – 65 kts Post-tropical/extratropical

• 120 hrs: 54.0°N 162.0°W – 60 kts Post-tropical/extratropical