8 AM: Olivia Forecast to Be Strong Tropical Storm When It Reaches Hawai‘i

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Monday, Sept. 10, 2018, 8 AM: Olivia Forecast to Be Strong Tropical Storm When it Reaches Hawai‘i.

At 8 a.m., Air Force Reserve Hurricane Hunters located the center of Category 1 Hurricane Olivia near latitude 21.8 north, longitude 148.1 west, 475 miles ENE of Hilo.

Olivia is moving toward the west near 8 mph, 2 mph slower that what was reported earlier this morning. A turn toward the WSW will start later today, and this motion is expected to continue through Wednesday.

On the forecast track, the center of Olivia will be moving over the main Hawaiian Islands Tuesday night into Wednesday.

Maximum sustained winds are still near 85 mph, with higher gusts.

Little change in strength is forecast today, with slight weakening starting tonight and continuing through Tuesday.

However, Olivia is forecast to be a strong tropical storm when it reaches the Hawaiian Islands.

Hurricane-force winds extend outward up to 30 miles from the center and tropical-storm-force winds extend outward up to 115 miles.

6 AM: Tropical Storm Warning Issued for Big Island

The NWS Central Pacific Hurricane Center in Honolulu has issued a Tropical Storm Warning for the Hawaiian Islands as Category 1 Hurricane Olivia approaches.

At 5 a.m. on Monday, Sept. 10, 2018. the warning was issued for Hawai‘i County and Maui County.

A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch is in effect for O‘ahu. A Tropical Storm Watch means that tropical storm conditions are possible in the watch area within 48 hours.

Interests on Kaua‘i and Ni‘ihau should closely monitor the progress of Olivia.

The center of Hurricane Olivia is located near latitude 21.7 north, longitude 148.0 west, about 480 miles ENE of Hilo. Olivia is moving toward the west near 10 mph. This general motion is expected to continue early today, followed by a turn toward the WSW starting later today. This WSW motion is expected to continue through Tuesday night. On this forecast track, tropical storm conditions are expected over parts of Hawai‘i starting late Tuesday.

Maximum sustained winds have increased overnight and are near 85 mph, with higher gusts. Little change in strength is forecast today, with slight weakening starting tonight and continuing through Tuesday. However, Olivia is forecast to be a strong tropical storm when it reaches the Hawaiian Islands.

Hurricane-force winds extend outward up to 30 miles from the center and tropical-storm-force winds extend outward up to 115 miles.

HURRICANE OLIVIA OVERVIEW

Hurricane Olivia is expected to bring strong winds, heavy rainfall and high surf to parts of the state. Olivia will continue moving toward the west early today, followed by an expected turn toward the WSW tonight. Based on the latest forecast track, Olivia will approach the main Hawaiian Islands on Tuesday and will likely move over portions of the island chain Tuesday night and Wednesday.

While remains too early to determine which island is at the greatest risk, the Big Island and Maui will be the first areas to experience impacts from Olivia.

Forecasters with the CPHC advise residents and visitors to not focus on the exact forecast track or intensity of Olivia and be prepared for changes in future forecasts.

Damaging tropical storm force winds may begin as early as Tuesday afternoon across the Big Island and Maui. Hurricane force wind gusts are possible as Olivia moves across the state Tuesday night and
Wednesday.

Forecasters said it is also important to remember that the mountainous terrain of Hawai‘i can produce localized areas of highly enhanced winds, even well away from the tropical cyclone center.

The chance for flooding rainfall will increase rapidly late Tuesday and will remain a significant threat through at least Wednesday. Preliminary storm total rainfall amounts are in the 10 to 15 inch
range, with isolated areas up to 20 inches. Much of this rainfall will be focused on windward areas, many of which already received substantial amounts of rain from recent Hurricane Lane. However, flooding will be a significant threat for all areas.

Large swells and surf generated by Hurricane Olivia will be the initial threat. Surf will slowly build over the next couple of days, and may become damaging on some east facing shores Tuesday and Wednesday. This is expected to result in significant beach erosion and overwash onto vulnerable coastal roadways, particularly during high tide.

SUMMARY: HAZARDS AFFECTING LAND

WIND: Tropical storm conditions are expected somewhere within the warning area starting late Tuesday. Tropical storm conditions are possible within the watch area starting early Wednesday morning.

RAINFALL: Olivia is expected to produce total rainfall accumulations of 10 to 15 inches. Isolated maximum amounts of 20 inches are possible, especially over windward sections of the Big Island and Maui County. This rainfall may produce life-threatening flash flooding.

SURF: Large swells generated by Olivia will spread from east to west across the Hawaiian Islands early this week. This will cause surf to build along exposed east facing shorelines as Olivia approaches. This surf may become damaging across parts of the state.