000 WTPA44 PHFO 082049 TCDCP4 Hurricane Kiko Discussion Number 35 NWS Central Pacific Hurricane Center Honolulu HI EP112025 Issued by NWS National Hurricane Center Miami FL 1100 AM HST Mon Sep 08 2025 The convective structure of Hurricane Kiko continues to degrade, with IR satellite imagery depicting a gradual warming of cloud tops, with convection become more ragged. Furthermore, a WSF-M microwave pass at 1625 UTC showed the core of the circulation tilting with height toward the north. The most recent Air Force Reserve Hurricane Hunter aircraft observed maximum flight-level winds of 88 kt at 700 mb in the northeast quadrant, suggesting that Kiko has maintained its intensity, despite the continued structural degradation. Assuming a slightly lower than typical 0.85 reduction factor at 700 mb, the intensity for this advisory is maintained at 75 kt, which is higher than both Dvorak and objective satellite intensity estimates. The most recent aircraft pass through the northwest quadrant indicated a strongly tilted vortex, with enhanced convection in the downshear-left quadrant. Kiko continues to move west-northwestward, with its estimated motion at 305/13 kt. For the next 12-24 hours this motion should continue as Kiko continues to be steered around the southwestern periphery of a subtropical ridge. However, as Kiko continues to experience strong southwesterly vertical wind shear, the vertical depth of the system is expected to decrease, with the more shallow circulation becoming subsequently steered by the low- to mid-level subtropical ridge to the north. This evolution is forecast to result in a gradual leftward turn but still west-northwestward as Kiko passes the longitude of the Hawaiian islands. The track guidance remains in good agreement, and the latest NHC track forecast is very close to the prior forecast, remaining close to a blend of the HCCA and TVCE consensus and Google Deep Mind ensemble mean (GDMI). The strong southwesterly vertical wind shear above 25 kts is expected to continue through 48 hours. Beyond that, SHIPS guidance suggests a brief decrease in shear from 48 to 72 hours, after which the shear increases again but shifting 180 degrees from southwesterly to northeasterly. Dry air continues to surround the circulation of Kiko, particularly upshear, which in light of the current shear, will accelerate the ventilation of the core convection. Weakening is forecast through the forecast period. The latest NHC intensity forecast is close to the middle of the guidance envelope through the 5 day period. Key Messages: 1. Kiko is forecast to pass north of the Hawaiian Islands on Tuesday and Wednesday. While the risk of direct impacts on the islands continues to decrease, interests there should continue to monitor Kiko's progress and the latest forecast. 2. Swells generated by Kiko are expected to gradually build and are forecast to peak along east-facing exposures of the Hawaiian Islands late today through the middle of the week, potentially producing life-threatening surf and rip currents. Listen to the latest updates and potential High Surf Warnings issued from the National Weather Service in Honolulu, Hawaii. FORECAST POSITIONS AND MAX WINDS INIT 08/2100Z 21.0N 149.9W 75 KT 85 MPH 12H 09/0600Z 21.8N 151.7W 60 KT 70 MPH 24H 09/1800Z 23.0N 154.2W 50 KT 60 MPH 36H 10/0600Z 23.9N 156.7W 45 KT 50 MPH 48H 10/1800Z 24.8N 159.4W 45 KT 50 MPH 60H 11/0600Z 25.5N 161.6W 45 KT 50 MPH 72H 11/1800Z 26.1N 163.8W 40 KT 45 MPH 96H 12/1800Z 27.5N 167.6W 35 KT 40 MPH 120H 13/1800Z 29.5N 169.5W 30 KT 35 MPH $$ Forecaster Shieh/Papin
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