Tropical Storm Warning for Hawaii Island is discontinued



A color enhanced infrared GOES-West satellite time-lapse movie of the Central Pacific September 6-13, 2018.

This is a Civil Defense Tropical Storm Olivia & Lower East Rift Zone update for 9:30 a.m.,  Wednesday, September 12, 2018.

The Central Pacific Hurricane Center reports that Tropical Storm Olivia continues to dissipate as it moves west across Maui. Although the tropical storm threat has passed, Hawaii Island remains under a Flash Flood Watch and isolated heavy rain and thunderstorms could still occur. A High Surf Advisory is also in effect for the east facing shores of the island.

For your information:

Lower East Rift Zone eruption information:

Thank you for your cooperation and patience over the past few months. Please have a safe day. This is your Hawaii County Civil Defense Agency.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for…

Interests in the Northwest Hawaiian Islands should monitor the progress of Olivia.

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

For storm information specific to your area, please monitor products issued by the National Weather Service office in Honolulu Hawaii.

DISCUSSION AND OUTLOOK

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At 5 a.m. HST (1500 UTC), the center of Tropical Storm Olivia was located near latitude 21.2 North, longitude 155.7 West. Olivia is moving toward the west near 12 mph (19 km/h), and this motion is expected to continue through this morning. A motion toward the west-southwest is expected later today, with an increase in forward speed. This general motion is then expected to continue the next couple of days.

Maximum sustained winds are near 45 mph (75 km/h) with higher gusts. Some weakening is forecast during the next 48 hours.

Tropical-storm-force winds extend outward up to 90 miles (150 km) from the center.

The estimated minimum central pressure is 1005 mb (29.68 inches).

HAZARDS AFFECTING LAND

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WIND: Tropical storm conditions are expected in Maui County today. Tropical storm conditions are expected to begin over Oahu later this morning. Remember that wind gusts can be much stronger near higher terrain, and in the upper floors of high-rise buildings. Winds can also be especially gusty through gaps between mountains and where winds blow downslope.

RAINFALL: Showers will continue to increase over the main Hawaiian Islands today. Olivia is expected to produce total rainfall accumulations of 5 to 10 inches in some areas, with isolated maximum amounts of 15 inches possible, especially in higher terrain. This rainfall may produce life-threatening flash flooding. Up to 6 inches of rain has already fallen over parts of Maui.

SURF: Large swells generated by Olivia will impact the main Hawaiian Islands over the next couple of days. This will result in dangerously high and potentially damaging surf, mainly along exposed east facing shores.

In the short term, Olivia is expected to move toward the west. However, the expectation is that the deep convection will wane later this morning, and Olivia will make a turn toward the west-southwest by this afternoon. After emerging to the west of Maui County this evening, the expectation is that terrain interaction and increasing vertical wind shear will prevent deep convection from persisting over the center. A motion toward the west-southwest is then expected through 36 hours, with the assumption that the LLCC will be intact after emerging to the southwest of Maui County. GFS guidance indicates dissipation within 48 hours, while the ECMWF carries a surface low through day 5. The official forecast splits the difference, with Olivia devolving to a post-tropical remnant low by day 3 before dissipation on day 5.

Key Message:

1. Flooding rainfall, high surf, and damaging winds are expected in the warning area. Significant impacts can occur well away from the center, especially when considering that the mountainous terrain of Hawaii can produce localized areas of strongly enhanced wind gusts and rainfall.

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Actions to take whenever a tropical storm or hurricane nears Hawaii

All of Hawaii’s citizens should know what to do during a hurricane, tropical storm watches and warnings. Watches and warnings are prepared for the Hawaiian Islands by the National Weather Service Central Pacific Hurricane Center in Honolulu. When watches and warnings are issued, people should closely monitor the Internet, radio, TV, or NOAA Weather Radio for official bulletins of the storm’s progress and instructions from civil defense authorities. Jim Weyman, director of the Central Pacific Hurricane Center, said, “Although you and your family may have never experienced a hurricane, don’t be complacent! It’s not a matter of if a hurricane will occur, but when one will occur. All of the Hawaiian Islands are at risk for a hurricane and we should all know what actions to take.”

For the Central Pacific Ocean a Hurricane/Tropical Storm Watch means hurricane/tropical storm conditions are possible in the specified area of the Watch, usually within 48 hours.

When a Hurricane or Tropical Storm Watch is issued:

For the Central Pacific Ocean a Hurricane/Tropical Storm Warning means hurricane/tropical storm conditions are expected in the specified area of the Warning, usually within 36 hours.

When a Hurricane or Tropical Storm Warning is issued:

The Central Pacific Hurricane Center (CPHC) issues tropical cyclone warnings, watches, advisories, discussions, and statements for all tropical cyclones in the Central Pacific from 140 Degrees West Longitude to the International Dateline. The season officially begins on June 1 and ends on November 30. However, tropical cyclones can occur at any time. The National Weather Service Forecast Office in Honolulu activates the CPHC when: (1) a tropical cyclone moves into the Central Pacific from the Eastern Pacific, (2) a tropical cyclone forms in the Central Pacific, or (3) a tropical cyclone moves into the Central Pacific from the West.

For links to the latest weather forecasts, reports, radar, webcam and satellite imagery visit our Weather Page at hawaii247.com/weather