Unstable weather conditions continue to churn above the island chain, bringing more heavy showers to Oahu, Kauai and Niihau on Saturday.

The weather will remain hotter and more humid than usual, and vog is also expected to move over Oahu Saturday through Labor Day, forecasters said.

A flash flood watch for Oahu and Kauai County issued Friday remains in effect through 6 p.m. Saturday.

The National Weather Service said a moist, unstable air mass over Kauai and Oahu, coupled with an upper-level trough just west of the state, will likely produce locally heavy showers and thunderstorms. Ground already saturated from recent heavy rain could increase the risk of flash flooding, the weather service said.

A day after heavy rain flooded businesses and closed roads downtown and in other areas of Oahu, another flash flood warning was issued for the island on Friday, with isolated heavy showers pounding Lualualei, Poamoho and other areas.

In the 24-hour period ending at 5 p.m. Friday, gauges at Poamoho recorded 3.50 inches of rain. The Pacific Tsunami Warning Center in Ewa Beach recorded 3.06 inches of rain during the same period. In a three-hour period between 11 a.m. and 2 p.m., 2.01 inches of rain fell on Lualualei and 1.86 inches on Palehua.

By midafternoon, the rain had mostly subsided, prompting the weather service to cancel the flash flood warning at 3:30 p.m.

Another flash flood warning was issued for Kauai at 5:24 p.m. Friday after radar showed stationary heavy rain 6 miles west of Kapaa or about 12 miles northwest of Lihue. Radar estimated rainfall rates were up to 3 inches per hour.

At about 6:15 p.m. Kauai police closed Kuhio Highway in the vicinity of the Hanalei Bridge after rain gauges indicated a rapid rise in the Hanalei River.

Areas covered in the warning included Haena, Wainiha, Na Pali State Park, Moloaa, Kalalau Valley, Princeville, Kilauea, Hanalei and Anahola. The warning remained in effect until 8:30 p.m.

Hawaii island also experienced heavy rain and flooding on Friday.

A flash flood warning was issued for Hawaii island at 3:06 p.m. and extended at 5:39 p.m. after radar showed heavy rain from Kailua-Kona to Keauhou. The rain was moving slowly southeast. Civil Defense officials reported lane closures due to flooding along Highway 11, south of Honaunau.

Areas covered in the warning included Kailua-Kona, Keauhou, Captain Cook and Honaunau.

Heavy ponding and debris prompted police to close Highway 11 near the 103-mile marker in Honaunau, Hualalai Road from Queen Kaahumanu Highway to Hienaloli Road, Kuakini Highway and Oni Oni Street.

In addition, traffic lights at Kealakaa Street and Palani Road were reported to be malfunctioning.

Meanwhile, a high surf warning for east shores of most islands remains in effect until 6 p.m. Saturday.

Surf generated by Jimena will reach 12 to 18 feet on east shores, forecasters said. The dangerous swell could continue into next week.

A storm near New Zealand has also generated advisory-level surf of 6 to 8 feet for south shores, prompting a high surf advisory effective until 6 p.m. Saturday.

Jimena is too far away to predict its exact impact on Hawaii’s weather, forecasters said. But like Ignacio, Jimena is expected to cut off the tradewinds as it moves north of the state as a tropical storm.

That will likely translate to a continuation of hot, humid weather and afternoon showers through at least the early part of next week.

After that, Jimena could take a turn to the southwest, again bringing rain as the system moves closer to the islands.

But forecasters caution that much could happen in the next week and it is far too early to predict the exact impact.

At 5 P.m. Friday, Jimena was about 620 miles east of Hilo and 795 miles east of Honolulu, moving north- northwest at a slow 3 mph.

Jimena had sustained winds of 75 mph. The hurricane-force winds extended for 40 miles and tropical storm-force winds extended outward for 230 miles.

The storm is expected to gradually weaken and move slowly northwest, far east of the state.

Ignacio briefly intensified into a hurricane before dropping to tropical storm strength north of the islands with sustained winds of 65 mph.

At 5 p.m. Friday, Ignacio was about 1,060 miles north-northwest of Honolulu and about 810 miles north of French Frigate Shoals.

The storm was moving north at 16 mph.

Ignacio is expected to weaken and merge with a storm front moving toward Canada next week.

Surf generated by Ignacio hit 4 to 6 feet Friday, and was expected to drop to 3 to 5 feet along north shores on Saturday.

Out in the Western Pacific, Typhoon Kilo is sending a small west swell to the state. West shores should see 3- to 5-foot wave faces through Saturday.