EDITOR’S NOTE: This is an archive post of KHON2’s ongoing Lane coverage. Click here to view the most recent update.
As Lane weakens to a tropical depression 270 miles southwest of Lihue, it leaves lingering moisture that will produce heavy rainfall over portions of the islands today.
Any additional heavy rainfall over these highly saturated grounds could quickly lead to flash flooding and landslides.
The National Weather Service in Honolulu has issued a flood advisory for portions of Oahu until 8:00 a.m.
At 5:04 a.m., radar and rain gauges showed areas of moderate rain over the Koolau Range. Rainfall rates were generally around one inch per hour. Water levels on Manoa Stream have risen rapidly during the past couple of hours.
Locations in the advisory include but are not limited to Honolulu, Ahuimanu, Hauula, Waimanalo, Kailua, Manoa, Maunawili, Kaneohe, Waikane, Kaneohe Marine Base, Hawaii Kai, and Laie.
A flash flood watch continues for Kahoolawe, Lanai, Maui, Molokai, Oahu, and the Big Island through this afternoon.
As for Lane, the depression is moving toward the west near 10 mph. Lane is then expected to accelerate northwestward by Tuesday as it transitions to an extratropical low.
Maximum sustained winds are near 35 mph with higher gusts. Some weakening is forecast during the next 48 hours, and Lane is expected to become a post-tropical remnant low later today or tonight. In a couple of days, Lane may develop into a gale force extratropical low as it passes over portions of the Northwestern Hawaiian Islands.
- 19.1N 162.2W
- ABOUT 315 MI…510 KM WSW OF HONOLULU HAWAII
- ABOUT 270 MI…435 KM SW OF LIHUE HAWAII
MAXIMUM SUSTAINED WINDS…35 MPH…55 KM/H
PRESENT MOVEMENT…W OR 260 DEGREES AT 10 MPH…17 KM/H
MINIMUM CENTRAL PRESSURE…1006 MB…29.71 INCHES
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Although a few thunderstorms have recently developed in Lane’s northern semicircle, the low-level circulation remains exposed. The once powerful cyclone is in the process of becoming a post-tropical remnant low, as it remains embedded in a hostile environment characterized by 40-50 kt of vertical wind shear. The initial intensity for this advisory has been lowered to 30 kt based on decreasing Dvorak intensity estimates that are near 2.0/30 kt, and an 0821Z ASCAT pass that detected winds of 30 kt, mainly in the northern semicircle.
The initial motion for this advisory is 260/9 kt. A surface high to the distant northeast will keep Lane moving generally toward the west into Monday as it devolves into a post-tropical remnant low, probably by later today or tonight. Once Lane becomes post-tropical, redevelopment into a tropical cyclone is highly unlikely. A brief slowing in forward speed is expected Monday night as the remnant low reaches the southwestern edge of the high and begins to interact with a developing mid-level low to its west. Assuming Lane survives as a coherent feature until then, this interaction is expected to lead to the development of an extratropical low by Tuesday/Wednesday. This low could bring gale force winds to portions of the Papahanaumokuakea Marine National Monument as it tracks north and northwest around the middle of the week. The latest official forecast track is close to the TVCE consensus while the intensity forecast is supported by global model guidance.