Updated: September 28, 2023
Flood Advisory for Molokaʻi Until 4:45 p.m.
Update: (1:43 p.m. 8.23.21)
The National Weather Service has issued a Flood Advisory for the island of Molokaʻi in Maui County until 4:45 p.m.
At 1:43 p.m., radar indicated heavy rain over east Molokaʻi near Puʻuohōkū Ranch and over Hālawa Valley. Rain was falling at a rate of 1 to 2 inches per hour and is expected to spread westward over the next several hours. Some locations that will experience flooding include: Kamalo, Kalaupapa National Park, ʻUalapuʻe, Kawela, Pūkoʻo, Hālawa Valley and Kualapuʻu.
The public is reminded to stay away from streams, drainage ditches and low-lying areas prone to flooding.
A Flash Flood Watch is also in effect for Maui County until 6 a.m. Tuesday, Aug. 24, 2021.
Flood Advisory Issued for Maui Until 2:15 p.m.
Update: (11:08 a.m. 8.23.21)
The National Weather Service has issued a Flood Advisory for the island of Maui until 2:15 p.m.
At 11:08 a.m., radar showed heavy rain over southeastern Haleakalā. The highest rain rates of 1-2 inches per hour were occurring from Kaupō Gap to Kahikinui. The NWS says this rainfall is expected to continue for several hours. The NWS says some locations that will experience flooding include: Kaupō, Kiīpahulu, Kēōkea and Haleakalā National Park.
The public is advised to stay away from streams, drainage ditches and low-lying areas prone to flooding.
A Flash Flood Watch is also in effect for Maui County through tonight.
Gale Low Centered Just NE of Hāna, Maui
Update: (5:19 a.m. 8.23.21)
The National Weather Service says circulation associated with the gale low appears to be centered just northeast of Hāna, Maui early this morning.
“The strong thunderstorms, which had been located in the north quadrant of this low last evening, have dissipated during the past few hours. Rainbands continue to form and rotate counter-clockwise around this low. These rainbands are currently impacting portions of Maui, Molokaʻi, and Oʻahu,” according to the latest forecast discussion issued by the NWS.
The NWS says that based on the latest guidance, the low will continue to track westward across Maui County this morning and the center may pass just south of Oʻahu this afternoon, and then move south of Kauaʻi this evening.
The current forecast continues to indicate that the coverage of clouds and the intensity of the showers will increase later today, especially over most windward areas.
A Wind Advisory, which includes wind gusts to 50 mph, has also been issued for the smaller islands from Molokaʻi and Lānaʻi to Kauaʻi. “The confidence in these strong winds occurring is highest for Oʻahu and Kauaʻi, which will likely be in the stronger northern semicircle of the westward moving circulation,” the NWS said.
In addition, the NWS notes that thunderstorms have been developing at times in the northern side of the gale low during the past couple of days. “If these redevelop later today, this may put Oʻahu and Kauaʻi in some of the heaviest rainfall.”
Note: For Molokaʻi and Lānaʻi, “the steadily backing wind profile as the low passes will lead to highly variable conditions with some areas experiencing light or variable winds with intermittent higher wind gusts, especially in thunderstorms.”
The NWS says more typical trade wind weather is expected to gradually return from Tuesday into mid-week.
Flood Watch Continues Through Late Tonight
Update: (5:11 a.m. 8.23.21)
A Flash Flood Watch continues for Molokai, Kauaʻi, Maui, Lanaʻi, Niʻihau, Hawaiʻi Island, Oʻahu and Kahoʻolawe through late tonight.
The National Weather Service says a gale low associated with the remnants of former TC Linda is moving westward into the Hawaiian Islands this morning, creating unstable conditions that will produce rain showers across all islands, heavy at times, increasing the threat for flash flooding through late tonight.
According to the latest forecast, “Thunderstorms may also anchor over island mountains as strong winds with this system produce heavier showers over higher terrain areas. Flood prone roads and other low-lying areas may be closed due to elevated runoff and overflowing streams. Urban areas may receive more significant flooding and property damage due to rapid runoff.”
The public is advised to be prepared to take action if a Flash Flood Warning is issued.
Remnants of Linda Expected to be “On Maui’s Doorstep” Sometime After 12 a.m.
“The remnants of former Tropical Cyclone Linda are expected to move through the islands between today and Monday night, bringing with it the potential for heavy rains that may result in flash flooding, and accompanied by locally breezy winds,” according to the latest forecast issued by the National Weather Service.
The smaller islands from Maui to Kauaʻi appear to be in “direct line” to experience the worst impacts of what forecasters are calling a “potent weather system.” “Even the Big Island, which appears to be to the south of the low’s track, will likely experience bouts of heavy rain, thunderstorms, and gusty winds.”
In a Forecast Discussion issued by the NWS at 8:35 p.m., the NWS said a “very gloomy forecast” has the potential of impacting the vast majority of the population.
“Loops of satellite imagery show the very prominent circulation associated with a gale low that appears to be centered about 90 miles east of Hāna. This low, which has been moving west at about 10 mph, has a large area of thunderstorms with tops in excess of 50 thousand feet to the north of the circulation center. Outer rainbands with heavy rainfall and strong gusty winds are also emanating from this low toward the west and southwest at this time,” according to the NWS.
Rainbands are already impacting the portions of the northern Big Island, Maui, Lānaʻi, and Molokaʻi.
“Since this system has tropical origins, it has likely corralled significant deep moisture within its inner core,” forecasters said. “As the strong winds and the deep tropical moisture begin to interact with the islands as the night progresses, there will be a serious deterioration in the weather conditions from east to west.”
“Based on the latest track guidance, we believe the center of the low will be on Maui’s doorstep some time after midnight HST. It will continue to bring its heavy rain and gusty winds across the rest of Maui County through early Monday morning,” according to the NWS forecast discussion.
“Unfortunately for Oʻahu, this means that by daybreak Monday, the weather will likely take a serious turn for the worst. Since the track of the low center could be just south of the island, flooding rains with heavy thunderstorms and gusty winds could make the morning commute very challenging,” forecasters said, noting that these conditions could persist for several hours.
The NWS says these “adverse weather conditions” will also likely spread to Kauaʻi during the daytime hours Monday, where”thunderstorms could also produce flash flooding and strong gusty winds.”
A Flash Flood Watch remains in effect for the state through Monday night. A Wind Advisory, which includes wind gusts to 50 mph, has also been issued for all of the smaller islands from Maui to Kauaʻi.
“In addition, the thunderstorms have been in the northern side of the gale low, so this may put Oahu and Kauai in some of the heaviest rainfall. Note that for Maui County, the steadily backing wind profile as the low passes will lead to highly variable conditions with some areas experiencing light or variable winds with intermittent higher wind gusts, especially in thunderstorms,” NWS forecasters said.
Forecasters say the weather is expected to improve with a return to a more trade wind pattern starting Tuesday, and lasting through the second half of the week.