Tropical Storm Warning for Maui, Hurricane Warning for Big Island

Iselle 5-day track 6 p.m. HST Wednesday, Aug. 6, 2014. Image courtesy CPHC/NOAA/NWS.

By Maui Now Staff

(Update: 8 p.m. 8/6/2014)

A hurricane warning continues for the Big Island of Hawaiʻi, and a tropical storm warning continues for Maui County as Hurricane Iselle continues on its path toward the state.

The Central Pacific Hurricane Center says the system was located 445 miles ESE of Hilo; 560 miles ESE of Kahului, Maui; 610 miles ESE of Kaunakakai, Molokaʻi; and 585 miles ESE of Lānaʻi City at 8 p.m. on Wednesday, Aug. 6, 2014.

Satellite imagery of Iselle at 7 p.m. HST, Wednesday, Aug. 6, 2014. Image courtesy CPHC/NOAA/NWS.

A tropical storm warning means that tropical storm conditions are expected in the warning area within 36 hours. The CPHC forecasts tropical storm conditions to begin impacting Maui County on Thursday night.

Swells generated by Iselle will continue to build along east facing shores tonight with very large damaging surf expected along mainly east and south shores starting late tonight or Thursday.

Rainfall totals of 5 to 8 inches, with isolated maximum amounts to 12 inches, are expected along the track of Iselle. These rains could cause life-threatening flash floods and rock and mud slides.

The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters. The surge will be accompanied by large and damaging waves. Surge related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances.

A flash flood watch is also in effect for the state of Hawaiʻi from 4 a.m. on Thursday to 6 a.m. on Saturday.

Another hurricane, Julio was last located 1450 miles ESE of Hilo and is projected to impact the state on Sunday, potentially as a tropical storm.

Iselle 5-day track 11 a.m. HST Wednesday, Aug. 6, 2014. Image courtesy CPHC/NOAA/NWS.

(Update: 3:15 p.m. 8/6/2014)

A hurricane warning has been issued for the Big Island of Hawaii, and Maui County is under a tropical storm warning as Hurricane Iselle continues on its path toward the state.

The warnings indicate that impacts are expected within the warning areas within the next 36 hours.

Hurricane Iselle is currently 560 miles ESE of Hilo; 670 miles ESE of Kahului, Maui; 720 miles ESE of Kaunakakai, Molokaʻi; and 695 miles ESE of Lānaʻi City.

The system was moving WNW at 16 mph, with sustained winds near 90 mph.

Potential Impacts, Rain:

Anticipated impacts include rainfall amounts of 5 to 8 inches, with some isolated locations receiving as much as 12 inches of rain. Forecasters are also advising that winds, surf and storm surge can pose potential impacts as well.

Potential Impacts, Winds:

Based on the latest forecast track, winds will be as high as 60 to 70 mph, with 85 mph gusts on Hawaiʻi Island, affecting the island on Thursday afternoon and evening.  In Maui County, winds are forecast to be 45 to 55 mph with 65 mph gusts. The impacts in Maui County are expected to begin Thursday night and continue through late Friday morning.

Forecasters with the National Weather Service say gusts will be strongest over mountainous terrain, through passes, and where winds blow downslope. Winds affecting the upper floors of high rise buildings will be significantly stronger than those near ground level.

The NWS advises homeowners that damage to shingles, siding, gutters and windows may occur, especially if these items are not properly secured.  Loose outdoor items have the potential of becoming airborne and could cause additional damage or injury.

Potential Impacts, High Surf:

• Big Island of Hawaiʻi: beginning today 15 to 25 feet, favoring east facing shores
• Maui County: 12 to 18 feet east facing beginning today, 10 to 15 feet south facing on Friday
• Oʻahu: 10 to 15 feet, favoring east facing shores beginning today and south facing shores on Friday
• Kauaʻi: 10 to 15 feet, favoring east facing shores tonight and south facing shores on Friday

(Update: 10:55 a.m. 8/6/2014)

Hurricane Iselle is now located 625 miles ESE of Hilo Hawaiʻi, and was moving WNW at 16 mph, with sustained winds near 90 mph, according to an updated forecast issued by the National Weather Service at 11 a.m on Wednesday, Aug. 6, 2014.

The agency also issued a hurricane warning for Hawaiʻi County, and a tropical storm warning for Maui County.

A hurricane warning means that hurricane conditions are expected somewhere within the warning area. The NWS says a warning is usually issued 36 hours before the anticipated impacts including tropical storm force winds. Under such conditions, authorities advise that preparations to protect life and property should be rushed to completion.

Here in Maui County, a tropical storm warning is in effect, meaning that tropical storm conditions are expected within the warning area within 36 hours.

The system is still on track to pass near the Big Island of Hawaiʻi on Thursday night.

NWS forecasters say some weakening is forecast during the next 48 hours; however, Iselle may still be a hurricane as it passes near the Big Island.

Hurricane force winds extend outward from the center of the system up to 35 miles, and tropical storm force winds extend outward up to 115 miles.

Hurricane Julio is a few days behind Iselle and may impact the islands as soon as Sunday. Julio was still located 1645 miles ESE of Hilo and 1740 miles ESE of Kahului, Maui, and had maximum sustained winds near 75 mph.

IMPACTS:

WIND: Tropical storm conditions are expected on the Big Island of Hawaiʻi Thursday, with hurricane conditions expected Thursday night, the NWS states. Tropical storm conditions are expected for portions of Maui County Thursday night, with possible impacts over Oʻahu on Thursday night or Friday.

Based on the latest forecast track, winds over 40 mph are expected to begin on Thursday afternoon, and early Thursday evening.  The NWS says winds in some areas of Maui County will be as high as 45 to 55 mph with 65 mph gusts. On the Big Island, winds in some areas will be as high as 60 to 70 mph with 85 mph gusts.

SURF: Swells generated by Iselle will reach the main Hawaiian Islands today with large, damaging surf expected along mainly East and South shores starting late tonight or Thursday.

The NWS forecast says increasing surf will occur today ahead of Iselle with surf heights reaching 15 to 25 feet on Thursday.

RAINFALL: Iselle is expected to produce rainfall amounts of 5 to 8 inches, with isolated maximum amounts to 12 inches in Maui County and Hawaiʻi Island, the NWS forecast states. These rains could cause life-threatening flash floods and rock and mud slides.  Inland flooding on other islands is projected to be slightly less at 4 to 7 inches, with isolated maximum amounts of 10 inches on Oʻahu, Kauaʻi and Niʻihau.

STORM SURGE: A combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters. The water could reach the following height above ground if the peak surge occurs at the time of high tide.

The “Astronomical High Tide” for Hāna Bay will be 2.7 feet at 1:42 p.m. on Thursday, and 2.9 feet at 2:18 p.m. on Friday.  The “Astronomical High Tide” for Hilo Bay will be 2.8 feet at 1:20 p.m. on Thursday, and 3 feet at 2:03 p.m. on Friday.

Forecasters say the high surf and high tide combination will bring coastal flooding along low-lying areas, with storm surge expected to reach 1 to 3 feet during the storm passage, and the threat of coastal flooding Thursday afternoon and night.