Update 9:30 a.m.

A flood advisory for Oahu has been extended until 11:45 a.m. today, according to National Weather Service Center forecasters.

“At 8:45 a.m., radar indicated moderate to heavy showers moving over oahu from the south therefore impacting leeward as well as windward areas. Rainfall rates between 1 and 2 inches in the heaviest showers will lead to ponding on roadways, including the H-1 and h-2 freeways through Central and Leeward Oahu,” forecasters said.

A flash flood watch for the entire state remains through late this afternoon.

Update 6 a.m.

The National Weather Service again extended a flood advisory for Oahu, this time until 9 a.m., after radar showed moderate to locally heavy showers moving over the island. Forecasters also expect an area of showers developing south of Oahu to move onshore over the next few hours.

A flash flood watch remains in effect for the entire state through this afternoon.

Update 4:30 a.m.

The National Weather Service extended a flood advisory for Oahu until 6 a.m. after radar showed heavy rain continuing to fall over much of the island. Rainfall rates of 1 to 2 inches per hour were seen in some areas.

Locations in the advisory include, but are not limited to, Honolulu, Maunawili, Kailua, Waikane, Waialua, Hawaii Kai, Salt Lake, Kaneohe, Waiahole, Moanalua and Halawa.

A flash flood watch remains in effect for the entire state through this afternoon.

Update 12:40 a.m.

The National Weather Service extended a flood advisory for Oahu after radar showed heavy showers and thunderstorms over the south shore of Oahu. The showers and thunderstorms are moving north over the rest of the island until early morning.

Rain was falling at a rate of 1 to 2 inches per hour and minor flooding can be expected, forecasters said.

The advisory, in effect until 3 a.m., includes Honolulu, Maunawili, Kailua, Waikane, Mililani, Waialua, Hawaii Kai, Salt Lake, Kaneohe, Waiahole, Moanalua and Halawa.

A flood advisory is also in effect for Kauai, where radar showed heavy rain over north Kauai with the Hanalei river rising close to flood stage at 11:16 p.m. The advisory is in effect until 2:15 a.m.

It includes Kapaa, Princeville, Kilauea, Wailua Homesteads, Na Pali State Park, Moloaa, Anahola, Kokee State park, Hanalie, Haena, Wainiha and Wailua.

Update 12 a.m.

The National Weather Service at 11:46 p.m. expanded a flash flood watch that was issued for Hawaii island to include the entire state.

The watch is in effect through Wednesday afternoon.

Deep tropical moisture will continue to provide heavy rainfall and a chance of thunderstorms, according to weather officials.

Update 11:47 p.m.

The National Weather Service at 11:25 p.m. issued a flood advisory for the island of Kauai until 2:15 a.m. Wednesday.

Radar at 11:16 p.m. showed heavy rain over northern parts of Kauai with the Hanalei river gauge rising close to flood stage. A flash flood warning may be needed if water levels continue to rise.

Locations of the advisory include Kapaa, Princeville, Kilauea, Wailua Homesteads, Na Pali State Park, Moloaa, Anahola, Kokee Sate Park, Hanalei, Haena, Wainiha and Wailua.

Update 10:05 p.m.

The National Weather Service canceled the flash flood warning for Oahu and extended a flash flood advisory until 1:15 a.m. Wednesday.

Locations of the advisory include Maunawili, Kailua, Waikane, Hauula, Kaneohe, Waiahole, Kahaluu, Kaneohe Marine Base, Ahuimanu, Kahuku, Punaluu and Kaaawa.

Doppler radar at 9:57 p.m. indicated heavy rain over windward Oahu falling at a rate of 1 to 2 inches per hour.

Minor flooding of low lying and poor drainage areas is to be expected.

Update 8:17 p.m.

The National Weather Service issued a flash flood warning for Oahu after radar showed heavy rain over the Koolau mountains, falling at a rate of 1 to 2 inches an hour just after 8 p.m.

The Waiahole Stream has risen just above flood stage, which, in the past, has led to flooding on Kamehameha Highway at Waiahole Valley Road.

The warning includes Maunawili,Kailua, Waikane, Hauula, Kaneohe, Waiahole, Kahaluu, Marine Base Hawaii in Kaneohe, Ahuimanu, Kahuku, Punaluu and Kaaawa.

Update 7 p.m.

The National Weather Service lifted flood advisories for Hawaii island and Maui after heavy afternoon rains and thunderstorms eased.

A flash flood watch for Hawaii island remains in effect until midnight.

Meanwhile, radar showed showers and thunderstorms passing near and south of Oahu this afternoon.

Radar also showed showers along the Koolau Mountains and North Shore.

Update 5:20 p.m.

The National Weather Service extended flood advisories for Hawaii island and Maui this evening as thunderstorms and heavy rain continued to fall over parts of the state.

At 4:36 p.m., radar showed heavy showers north of Kailua-Kona and along windward and southeast slopes of Hawaii island. The rain was falling at rates of 2 inches an hour and is expected to continue through the evening. The advisory for Hawaii island is in effect until 7:30 p.m.

Civil Defense Interim Administrator Ed Teixeira said three to four homes reported flooding near Mile Marker 53 in Waimea. The homes are in flat areas where there is no runoff.

Runoff flooded another Waimea home on Puu Nani Drive.

Workers from the county Department of Public Works delivered sand bags to affected residents, and the fire department also responded, he said.

Runoff also affected Saddle Road near Mile Marker 37 near the Pohakuloa Training Area. Water was coming across the highway, Teixeira said.

However, “no routes are blocked,” he said, except for Kukila Street in Hilo, due to ponding water, making it impassable.

“The good news, looking at the radar charts, looks like it’s improved and might have moved offshore,” Teixeira said at about 5:15 p.m. today.

On the Valley Isle, radar showed heavy rain falling at rates of up to 2 inches an hour across windward east Maui. The showers and thunderstorms are expected to linger into the evening and could lead to rapid rises in streams.

The advisory, in effect until 8 p.m., includes Haiku-Pauwela, Kaupo, Kipahulu, Huelo, Nahiku, Hana, Makawao, Paia, Kailua, Wailua and Haleakala National Park.

Hilo set rain records for the date Monday and today.

The National Weather Service said the 6.98 inches recorded at the airport so far today has already broken the old record of 3.59 inches set in 1982. On Monday, the 4.04 inches recorded broke the old record of 2.99 inches set in 1982.

In Honolulu, the 0.13 inches that fell at the airport broke the old record of 0.1 inches set in 1988.

The humidity and chance of heavy showers are expected to continue through Wednesday. Cooling tradewinds may return Thursday.

Update 2:45 p.m.

Maui is also under a flood advisory as radar showed afternoon showers beginning to fall on Oahu.

Heavy rains, with rates up to 3 inches per hour across Upcountry Maui are expected to persist through the afternoon, the National Weather Service said.

The rain was falling east of Kula, Pukalani and Makawao just before 2 p.m.

The advisory, in effect until 5 p.m., includes Haiku to Pauwela, Hailimaile, Paia, Pauwela, Keokea, Huelo, Nahiku, Kailua and Wailua.

Radar also showed rains developing over parts of Oahu, but no advisories have been issued.

Forecasters are also monitoring an area of heavy rains and thunderstorms south of Oahu. At this time, the rains are not expected to move north over the island.

However, with the heavy tropical moisture over the state, heavy rain showers can develop at any time over any area, said Derek Wroe, a meteorologist with the Honolulu office of the National Weather Service.

“We’re still going to have moist and unstable conditions over most of the state,” Wroe said.

Update 2:20 p.m.

The National Weather Service issued a flood advisory for all of Hawaii island until 4:45 p.m. after thunderstorms and heavy rain began falling over interior and upslope areas.

Forecasters also warned of the dangers from lightning strikes from the thunderstorms. They advised residents to move indoors and stay way from windows and electrical appliances.

The heaviest rain is happening upslope of Milolii to Kailua-Kona with more rain just south of Kamuela and the Pohakuloa Training Area.

“Runoff from this rainfall may impact downslope leeward coastal areas even in areas where little to no rainfall is occurring,” the National Weather Service said.

Rain rates of 2 to 3 inches are expected as the showers move slowly north.

Forecasters said people should stay away from streams, drainage ditches and low-lying areas prone to flooding.

The rain is also causing hazardous driving conditions because of water on roads and reduced visibility.

People should not cross fast-flowing or rising water. “Turn around, don’t drown,” forecasters advised.

Original story:

Expect at least another day of hot, humid and wet conditions throughout the state, with Hawaii island under a flash flood watch because of the chance of thunderstorms.

In addition, National Weather Service forecasters said, vog could blow over Oahu and other islands because of the light, easterly and southeasterly winds.

Deep tropical moisture and unstable atmospheric conditions over and around the Big Island will continue to produce heavy rain and a chance of thunderstorms through this evening, they said.

“With the ground already saturated in many areas from heavy rains during the past couple of days, there will be an elevated risk for flash flooding,” the weather service said.

Radar and satellite images show a band of heavy showers about 35 miles south of Oahu stretching west and northwest of the Big Island.

The rain is not expected to reach Oahu right away, however there is a chance of thunderstorms developing on all islands this afternoon.

Forecasters expect the hot and humid conditions to produce afternoon showers in leeward and interior sections regardless of whether the heavy rain south of Oahu and Kauai moves ashore.

The heat, humidity, rain and vog should continue through Wednesday. Cooling tradewinds are expected to return Thursday.

The forecast for Honolulu and south shores of Oahu calls for partly sunny skies this morning with scattered showers and isolated thunderstorms in the afternoon and the chance of vog. Highs will between 84 and 90 degrees and locally heavy rain is possible.

Expect more scattered showers and vog tonight with lows between 65 and 74.

Wednesday’s weather should be similar to today.