Tropical Cyclone Discussion
279 WTPA42 PHFO 130251 TCDCP2 Potential Tropical Cyclone One-C Discussion Number 3 NWS Central Pacific Hurricane Center Honolulu HI CP012026 Issued by NWS National Hurricane Center Miami FL 500 PM HST Wed Aug 12 2026 The disturbance remains poorly organized, with at least two mesovortices rotating around the larger circulation. A recent OSCAT pass also shows a very elongated circulation, with gale-force winds confined to the northeastern quadrant. There has been some suggestion in recent imagery that the southern side of the circulation is becoming more dominant, but the overall system is still too ill-defined to be considered a tropical cyclone. The initial wind speed remains 35 kt per earlier scatterometer data. The overall circulation envelope appears to be moving westward at about 8 kt. A large high pressure system north of the Hawaiian Islands should cause a west to west-northwestward track of the disturbance for the next several days. At this point, the track forecast is highly dependent on where a true center forms, with the most northward model formations generally gaining the most latitude, and the southward model solutions usually staying just south of the Hawaiian Islands. The overall model trend is slightly south of the previous forecast, and the new forecast is adjusted in that direction. This should not be considered a high-confidence prediction given the uncertainties on where a center will form. The environment should generally be conducive for intensification during the next few days with warm sea-surface temperatures, low-to-moderate vertical wind shear and ample low- to mid-level humidities in the system's path. Due to the sprawling structure, only a gradual strengthening is anticipated. The intensity forecast near the Hawaiian Islands is challenging because of land interaction and an upper-low dropping near the cyclone. Models tonight generally show a more conducive trough interaction than a high-shear one, and the system is expected to be near hurricane strength by the time it nears the Hawaiian Islands. The new intensity forecast is slightly higher than the previous one, but is leveled off near Hawaii. This forecast could be conservative beyond 3 days, especially if the system moves south of expected. Key Messages: 1. The disturbance is expected to become a tropical storm on Thursday and strengthen while it moves west-northwestward near or over the Hawaiian Islands late this week and this weekend. Although it is too soon to specify the exact location and magnitude of impacts, residents should closely monitor the latest forecast updates and ensure that they have their preparedness plan in place. 2. Heavy rainfall associated with the system will begin to impact the Big Island Friday, spreading westward into Maui Saturday, and Lanai, Molokai, Oahu and Kauai on Sunday. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. 3. There is an increasing risk of wind and wave impacts in the Hawaiian Islands regardless of the exact track and intensity of the system. Hurricane or Tropical Storm Watches may be required for portions of the Hawaiian Islands early Thursday. FORECAST POSITIONS AND MAX WINDS INIT 13/0300Z 14.8N 143.5W 35 KT 40 MPH...POTENTIAL TROP CYCLONE 12H 13/1200Z 15.2N 144.6W 40 KT 45 MPH...POTENTIAL TROP CYCLONE 24H 14/0000Z 16.2N 146.6W 45 KT 50 MPH...TROPICAL CYCLONE 36H 14/1200Z 17.3N 149.0W 50 KT 60 MPH 48H 15/0000Z 18.1N 151.6W 55 KT 65 MPH 60H 15/1200Z 18.8N 154.1W 60 KT 70 MPH 72H 16/0000Z 19.6N 156.7W 60 KT 70 MPH 96H 17/0000Z 21.4N 162.2W 55 KT 65 MPH 120H 18/0000Z 23.3N 167.6W 60 KT 70 MPH