Kona low continues to draw up unstable moisture across the state

Flood Watch extended for Maui and Big Island until Sunday Afternoon
3:42 p.m., Saturday, Feb. 18, 2023

The National Weather Service has extended a Flood Watch for Maui and the Big Island through Sunday afternoon, Feb. 19, 2023.

The NWS says significant flooding may occur due to the overflow of streams and drainages. Continued moderate to heavy rainfall across saturated soil will maintain a flood threat for both islands.

Hawaiʻi Island Flood Warning extended to 10 p.m.
6:51 p.m., 3:46 p.m., 12:44 p.m., 9:43 a.m., 6:45 a.m., 5:14 a.m., Saturday, Feb. 18, 2023

The National Weather Service has extended the Flash Flood Warning for the island of Hawaiʻi until 10 p.m.

At 6:51 p.m., radar and rain gauges showed that rainfall rates have eased over the southeast flank of the Big Island, according to the NWS. However, runoff levels were still high, and the Hawaiʻi County Civil Defense Agency reported that Highway 11 at Kawa Flats, Wood Valley Road, and Kaalaiki Road were still closed in the Kaʻū District. Highway 130 in the Puna bound direction is also closed between mile markers 2 and 3. These roads will likely remain closed tonight, according to emergency managers.

The NWS reports that radar and rain gauges indicated that moderate to heavy rainfall was still moving over the South Hilo, Puna, and Kaʻū Districts from the southeast. Peak rain rates were around 1 inch per hour. Periods of heavy rainfall will continue through tonight.

Unstable moisture still in the forecast into Sunday
4:03 a.m., Saturday, Feb. 18, 2023

“An upper low southwest of the Hawaiian Islands continues to draw up a large band of deep tropical moisture within converging east to southeast wind flow,” according to the latest synopsis issued by the National Weather Service.

The NWS reports that this unstable tropical moisture band will keep widespread rainfall in the forecast, heavy at times, with developing thunderstorms across much of the state into Sunday.

“The low will slowly weaken from Sunday into Monday with decreasing rainfall trends as more stable trade winds begin to build in from the east,” the agency reports.

The NWS says another round of unstable showers may develop by Tuesday and Wednesday as another cut off low drops in west of the island chain.

More stable conditions return by next week Thursday as a high pressure ridge builds in from the northeast, according to the agency.

Kauaʻi Flash Flood Warning until 4:15 p.m.
1:01 p.m., Saturday, Feb. 18, 2023

The National Weather Service in Honolulu has extended the Flash Flood Warning for the island of Kauaʻi until 4:15 p.m.

At 1:01 p.m., radar showed that moderate to heavy rainfall was still moving over the east half of Kauaʻi from the southeast.

The NWS reports the Hanalei River water level was still elevated and was still expected to inundate Kūhiō Highway near the Hanalei Bridge. South Fork Wailua River was also running at a high level. Additional rainfall through the afternoon should keep streams and rivers in east Kauaʻi at high flow levels, according to the NWS.