000 WTPA44 PHFO 100857 TCDCP4 Tropical Storm Kiko Discussion Number 41 NWS Central Pacific Hurricane Center Honolulu HI EP112025 Issued by NWS National Hurricane Center Miami FL 1100 PM HST Tue Sep 09 2025 Satellite images show that the burst of deep convection which developed north of the low-level center of Kiko this afternoon has collapsed, likely due to the strong southwesterly vertical wind shear and the dry mid-level environment the cyclone is navigating. The most recent subjective Dvorak current intensity estimates from PHFO, SAB, and JTWC ranged from 1.5/25 kt to 2.0/30 kt, while the objective estimates from UW-CIMSS ranged from 31 to 36 kt. Based on a blend of these data, and accounting for little change in the satellite presentation during the past 12 hours or so, the initial intensity has been held at 35 kt for this advisory, keeping Kiko a tropical storm for now. Kiko’s movement has been a bit erratic since the previous advisory, with outflow from the collapse of a deep convective burst driving the low-level center south of due west since the previous advisory cycle. This motion appears to be modifying after the initial southward jog, with a west-northwestward motion expected to resume shortly. The initial motion for this advisory is set at a somewhat uncertain 280 degrees at 11 kt. This general west to west-northwest motion is expected to continue during the next several days as Kiko’s increasingly shallow circulation is steered by the low-level flow along the southwest periphery of a low- to mid-level ridge to the north and northeast. The latest track forecast has shifted south of the previous advisory to account for the southward jog, and is roughly a blend of the latest multi-model consensus HCCA/TVCE/FSSE aids and the AI-driven GDMI/EGMI aids. Kiko will remain over sufficiently warm water during the next 24 hours, while struggling with very dry mid-level air and moderate to strong southwesterly vertical wind shear. This should lead to continued slow weakening of the cyclone, and Kiko will likely become a tropical depression on Wednesday. Beyond 24 hours, the vertical wind shear decreases and waters will warm to 27–28C, but this will likely not be sufficient for intensification due to the very dry mid-level environment and increasing upper-level convergence. As a result, Kiko is expected to continue to weaken, with the forecast calling for the cyclone to become a post-tropical remnant low by 48 hours and dissipate entirely by 96 hours. The intensity forecast is very close to the previous forecast and is on the lower end of the various intensity aids. Key Messages: 1. Kiko is forecast to pass north of the western Hawaiian Islands tonight through early Wednesday. The threat of direct impacts continues to lower, although interests in the western Hawaiian Islands should continue to monitor Kiko's progress. 2. Swells generated by Kiko will peak over the exposed waters of the western Hawaiian Islands tonight and Wednesday, producing life-threatening surf and rip currents. Refer to the latest updates and forecasts issued by the National Weather Service in Honolulu, Hawaii. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 22.4N 157.1W 35 KT 40 MPH 12H 10/1800Z 22.9N 158.9W 30 KT 35 MPH 24H 11/0600Z 23.6N 161.2W 30 KT 35 MPH 36H 11/1800Z 24.2N 163.5W 25 KT 30 MPH 48H 12/0600Z 24.9N 165.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 12/1800Z 25.6N 167.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 13/0600Z 26.2N 170.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 14/0600Z...DISSIPATED $$ Forecaster Jelsema (CPHC)
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