(BIVN) – Potential Tropical Cyclone One-C has formed in the Central Pacific and the forecast track has it nearing the Hawaiian islands by late Friday as a tropical storm.
One-C, the future Tropical Cyclone Lala, was already 935 miles east southeast of Hilo as of Wednesday morning. Heavy rainfall associated with the system is expected to begin to impact Hawaiʻi Island by Friday. There is an increasing risk of wind and wave impacts in the Hawaiian Islands, regardless of the exact track and intensity of the system, forecasters say.
The Central Pacific Hurricane Center says a Hurricane or Tropical Storm Watch will likely be required for the Hawaiian islands by early Thursday.
The National Weather Service noted fire weather concerns will also increase on Friday, as winds begin to strengthen, “and a dry and stable air mass with low relative humidity in advance of the storm will likely lead to high wildfire potential.”
“We are closely tracking the development of this storm system and actively preparing for any hazards that could affect our island,” said Mayor Kimo Alameda in a statement issued Tuesday. “While the magnitude of impacts is uncertain at this time, the best way to keep you and your family safe is to prepare now and stay connected. Take the time to check on your home and follow official County channels, including our emergency alerts, and local news sources for updates.”
From the Central Pacific Hurricane Center discussion posted at 5 a.m. HST:
The disturbance well to the east-southeast of the Hawaiian Islands is expected to become a tropical storm within the next day or so and be near the Islands by late Friday. Given the potential for significant impacts over the Hawaiian Islands, Potential Tropical Cyclone advisories are being initiated at this time. The system’s cloud pattern is elongated from southwest to northeast with most of the deep convection well to the southwest of the center. The disturbance currently lacks sufficiently organized convection to be classified as a tropical cyclone, and the Dvorak classifications from Honolulu are T1.0/1.0. Scatterometer data suggests that the intensity is near 30 kt.
Satellite fixes indicate that the system is moving generally westward and the initial motion estimate is 270/9 kt. Dynamical models show a mid-level high pressure system persisting to the north of the disturbance. This steering pattern should result in a generally west-northwestward track for the next several days. The simple and corrected model consensus and Google DeepMind track predictions are in reasonable agreement, and the official forecast follows this guidance closely. Given that the system is still in the formative stage, the precise track is still somewhat uncertain.
The atmospheric and oceanic environment look conducive for gradual strengthening during the next few days. Based on the intensity models, the system is expected to be nearing hurricane strength by the time it nears the Hawaiian Islands. However, an upper-level low/trough could limit strengthening while the system passes near or over the Islands.
Key Messages:
1. The disturbance is expected to become a tropical storm later today or tonight 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 is expected to begin to impact the Big Island Friday, spreading westward into Maui on Saturday, and across 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 tonight or early Thursday.
